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fallow_extract/
sfc.rs

1//! Vue/Svelte Single File Component (SFC) script and style extraction.
2//!
3//! Extracts `<script>` block content from `.vue` and `.svelte` files using regex,
4//! handling `lang`, `src` metadata, and `generic` attributes, and filtering
5//! HTML comments. Vue external script references are emitted as graph edges;
6//! Svelte markup-level script `src` references are treated as runtime HTML.
7//! Also extracts `<style>` block sources (`@import` / `@use` / `@forward` /
8//! `@plugin` and `<style src="...">`) so referenced CSS / SCSS files become
9//! reachable from the component, preventing false `unused-files` reports on
10//! co-located styles.
11
12use std::path::Path;
13use std::sync::LazyLock;
14
15use oxc_allocator::Allocator;
16use oxc_ast_visit::Visit;
17use oxc_parser::Parser;
18use oxc_span::SourceType;
19use rustc_hash::{FxHashMap, FxHashSet};
20
21use crate::asset_url::normalize_asset_url;
22use crate::parse::{
23    compute_auto_import_candidates, compute_import_binding_usage, compute_semantic_usage,
24};
25use crate::sfc_template::{SfcKind, collect_template_usage_with_bound_targets};
26use crate::source_map::ExtractionResult;
27use crate::visitor::ModuleInfoExtractor;
28use crate::{ImportInfo, ImportedName, ModuleInfo};
29use fallow_types::discover::FileId;
30use fallow_types::extract::{FunctionComplexity, byte_offset_to_line_col, compute_line_offsets};
31use oxc_span::Span;
32
33/// Regex to extract `<script>` block content from Vue/Svelte SFCs.
34/// The attrs pattern handles `>` inside quoted attribute values (e.g., `generic="T extends Foo<Bar>"`).
35static SCRIPT_BLOCK_RE: LazyLock<regex::Regex> = LazyLock::new(|| {
36    crate::static_regex(
37        r#"(?is)<script\b(?P<attrs>(?:[^>"']|"[^"]*"|'[^']*')*)>(?P<body>[\s\S]*?)</script>"#,
38    )
39});
40
41/// Regex to extract the `lang` attribute value from a script tag.
42static LANG_ATTR_RE: LazyLock<regex::Regex> =
43    LazyLock::new(|| crate::static_regex(r#"lang\s*=\s*["'](\w+)["']"#));
44
45/// Regex to extract the `src` attribute value from a script tag.
46/// Requires whitespace (or start of string) before `src` to avoid matching `data-src` etc.
47static SRC_ATTR_RE: LazyLock<regex::Regex> =
48    LazyLock::new(|| crate::static_regex(r#"(?:^|\s)src\s*=\s*["']([^"']+)["']"#));
49
50/// Regex to detect Vue's bare `setup` attribute.
51static SETUP_ATTR_RE: LazyLock<regex::Regex> =
52    LazyLock::new(|| crate::static_regex(r"(?:^|\s)setup(?:\s|$)"));
53
54/// Regex to detect Svelte's `context="module"` attribute (Svelte 4).
55static CONTEXT_MODULE_ATTR_RE: LazyLock<regex::Regex> =
56    LazyLock::new(|| crate::static_regex(r#"context\s*=\s*["']module["']"#));
57
58/// Regex to detect Svelte 5's bare `module` script attribute (`<script module>`,
59/// `<script module lang="ts">`). Anchored like [`SETUP_ATTR_RE`] so `module` must
60/// be a standalone attribute, not a substring of another attr name (e.g.
61/// `data-module`) or value.
62static SVELTE_MODULE_ATTR_RE: LazyLock<regex::Regex> =
63    LazyLock::new(|| crate::static_regex(r"(?:^|\s)module(?:\s|$|=)"));
64
65/// Regex to extract Vue's `generic="..."` attribute value (script-setup
66/// generics). Matches the contents between the quotes and stops at the
67/// closing quote, mirroring `LANG_ATTR_RE`.
68static VUE_GENERIC_ATTR_RE: LazyLock<regex::Regex> = LazyLock::new(|| {
69    crate::static_regex(r#"(?:^|\s)generic\s*=\s*"([^"]*)"|(?:^|\s)generic\s*=\s*'([^']*)'"#)
70});
71
72/// Regex to extract Svelte's `generics="..."` attribute value (Svelte 4
73/// generic script attribute, repurposed by some Svelte 5 code).
74static SVELTE_GENERICS_ATTR_RE: LazyLock<regex::Regex> = LazyLock::new(|| {
75    crate::static_regex(r#"(?:^|\s)generics\s*=\s*"([^"]*)"|(?:^|\s)generics\s*=\s*'([^']*)'"#)
76});
77
78/// Regex to match HTML comments for filtering script blocks inside comments.
79static HTML_COMMENT_RE: LazyLock<regex::Regex> =
80    LazyLock::new(|| crate::static_regex(r"(?s)<!--.*?-->"));
81
82/// Regex to detect a whole-object prop/attr spread in a Vue template:
83/// `v-bind="$attrs"`, `v-bind="$props"`, or `v-bind="props"` (with single or
84/// double quotes). A bound prop may be consumed indirectly, so the
85/// `unused-component-prop` detector abstains on the whole file when this matches.
86static PROPS_ATTRS_SPREAD_RE: LazyLock<regex::Regex> =
87    LazyLock::new(|| crate::static_regex(r#"v-bind\s*=\s*["'](?:\$attrs|\$props|props)["']"#));
88
89/// FP-1 (unused-load-data-key): a SvelteKit route component passing the whole
90/// `data` prop opaquely in MARKUP, where a child reads arbitrary keys the
91/// detector cannot see. Matches `data={data}` (whole-prop pass to a child) and
92/// `{...data}` (Svelte template spread). The script-side `const x = {...data}` /
93/// `fn(data)` / `const X = data` forms are captured by the JS visitor instead.
94/// Only a whole-`data` pass forces the abstain; `data.x` member access stays a
95/// credited consumer.
96static SVELTE_TEMPLATE_DATA_WHOLE_USE_RE: LazyLock<regex::Regex> =
97    LazyLock::new(|| crate::static_regex(r"(?:=\s*\{\s*data\s*\}|\{\s*\.\.\.\s*data\s*\})"));
98
99/// Matches an emit-style call in template markup: a callee identifier (or
100/// `$emit`) followed by `(` and its first argument. Group 1 is the callee name
101/// (filtered against the harvested emit binding / `$emit` by the caller), groups
102/// 2 and 3 are a string-literal first arg (single- or double-quoted: the event
103/// name, credited as used), and group 4 is the first non-space character of a
104/// NON-literal first arg (a dynamic emit, whose event name is unknowable, forcing
105/// a whole-file abstain). Event names allow kebab and namespaced forms
106/// (`update:modelValue`, `my-event`). The Rust `regex` crate has no
107/// backreferences, so the two quote styles are separate alternatives.
108static TEMPLATE_EMIT_CALL_RE: LazyLock<regex::Regex> =
109    LazyLock::new(|| crate::static_regex(r#"([\w$]+)\s*\(\s*(?:'([\w:-]*)'|"([\w:-]*)"|(\S))"#));
110
111/// Regex to extract `<style>` block content from Vue/Svelte SFCs.
112/// Mirrors `SCRIPT_BLOCK_RE`: handles `>` inside quoted attribute values and
113/// captures the body so `@import` / `@use` / `@forward` directives can be parsed.
114static STYLE_BLOCK_RE: LazyLock<regex::Regex> = LazyLock::new(|| {
115    crate::static_regex(
116        r#"(?is)<style\b(?P<attrs>(?:[^>"']|"[^"]*"|'[^']*')*)>(?P<body>[\s\S]*?)</style>"#,
117    )
118});
119
120/// Static asset references in SFC markup: `<img src="./logo.png">`,
121/// `<source src="...">`, `<video poster="...">`, etc.
122///
123/// Scoped to genuine asset elements (`img` / `source` / `video` / `audio` /
124/// `track` / `embed`) so a custom component's `src` PROP (`<MyImage src="./x">`)
125/// is never misread as an asset edge. ONLY plain relative literals (`./` or
126/// `../`) are captured: dynamic bindings (`:src`, `v-bind:src`, `bind:src`,
127/// `src={...}`, `data-src`), alias-prefixed (`@/`), root-relative (`/foo`),
128/// remote, interpolated (`{{ }}` / `{ }`), and query/hash-suffixed values are
129/// all skipped (the value class excludes `{`, `?`, `#`, whitespace, and angle
130/// brackets, and the alternation anchors on a leading `./` or `../`). A
131/// captured ref becomes a `SideEffect` import; an existing asset resolves to
132/// `ExternalFile` (no finding) and a genuinely-missing one surfaces as
133/// `unresolved-import` on the trusted resolver path.
134static TEMPLATE_ASSET_RE: LazyLock<regex::Regex> = LazyLock::new(|| {
135    crate::static_regex(
136        r#"(?si)<(?:img|source|video|audio|track|embed)\b(?:[^>"']|"[^"]*"|'[^']*')*?\s(?:src|poster)\s*=\s*(?:"((?:\./|\.\./)[^"<>{}?#\s]*)"|'((?:\./|\.\./)[^'<>{}?#\s]*)')"#,
137    )
138});
139
140/// Mask `<script>` / `<style>` blocks and HTML comments to equal-length spaces
141/// so a markup-region scan (asset refs) sees only the template, while byte
142/// offsets still map 1:1 into the original source for line/col reporting.
143fn mask_non_markup_regions(source: &str) -> String {
144    let mut masked = source.to_string();
145    for re in [&*SCRIPT_BLOCK_RE, &*STYLE_BLOCK_RE, &*HTML_COMMENT_RE] {
146        masked = re
147            .replace_all(&masked, |caps: &regex::Captures<'_>| {
148                " ".repeat(caps[0].len())
149            })
150            .into_owned();
151    }
152    masked
153}
154
155/// Collect static relative asset references from SFC markup as
156/// `(normalized_specifier, value_span)` pairs. See [`TEMPLATE_ASSET_RE`].
157fn collect_template_asset_refs(source: &str) -> Vec<(String, Span)> {
158    let masked = mask_non_markup_regions(source);
159    let mut refs = Vec::new();
160    for caps in TEMPLATE_ASSET_RE.captures_iter(&masked) {
161        let Some(value) = caps.get(1).or_else(|| caps.get(2)) else {
162            continue;
163        };
164        let raw = value.as_str();
165        if raw.is_empty() {
166            continue;
167        }
168        refs.push((
169            normalize_asset_url(raw),
170            Span::new(value.start() as u32, value.end() as u32),
171        ));
172    }
173    refs
174}
175
176/// An extracted `<script>` block from a Vue or Svelte SFC.
177pub struct SfcScript {
178    /// The script body text.
179    pub body: String,
180    /// Whether the script uses TypeScript (`lang="ts"` or `lang="tsx"`).
181    pub is_typescript: bool,
182    /// Whether the script uses JSX syntax (`lang="tsx"` or `lang="jsx"`).
183    pub is_jsx: bool,
184    /// Byte offset of the script body within the full SFC source.
185    pub byte_offset: usize,
186    /// External script source path from `src` attribute.
187    pub src: Option<String>,
188    /// Span of the `src` attribute value in the full SFC source.
189    pub src_span: Option<Span>,
190    /// Whether this script is a Vue `<script setup>` block.
191    pub is_setup: bool,
192    /// Whether this script is a Svelte module-context block.
193    pub is_context_module: bool,
194    /// Type-parameter list from a `generic="..."` (Vue) or `generics="..."`
195    /// (Svelte) attribute on the script tag. Holds the bare constraint, no
196    /// surrounding angle brackets, e.g. `T extends Test<boolean>`.
197    pub generic_attr: Option<String>,
198}
199
200/// Extract all `<script>` blocks from a Vue/Svelte SFC source string.
201pub fn extract_sfc_scripts(source: &str) -> Vec<SfcScript> {
202    let comment_ranges: Vec<(usize, usize)> = HTML_COMMENT_RE
203        .find_iter(source)
204        .map(|m| (m.start(), m.end()))
205        .collect();
206
207    SCRIPT_BLOCK_RE
208        .captures_iter(source)
209        .filter(|cap| {
210            let start = cap.get(0).map_or(0, |m| m.start());
211            !comment_ranges
212                .iter()
213                .any(|&(cs, ce)| start >= cs && start < ce)
214        })
215        .map(|cap| {
216            let attrs = cap.name("attrs").map_or("", |m| m.as_str());
217            let body_match = cap.name("body");
218            let byte_offset = body_match.map_or(0, |m| m.start());
219            let body = body_match.map_or("", |m| m.as_str()).to_string();
220            let lang = LANG_ATTR_RE
221                .captures(attrs)
222                .and_then(|c| c.get(1))
223                .map(|m| m.as_str());
224            let is_typescript = matches!(lang, Some("ts" | "tsx"));
225            let is_jsx = matches!(lang, Some("tsx" | "jsx"));
226            let src = SRC_ATTR_RE
227                .captures(attrs)
228                .and_then(|c| c.get(1))
229                .map(|m| m.as_str().to_string());
230            let attrs_start = cap.name("attrs").map_or(0, |m| m.start());
231            let src_span = SRC_ATTR_RE.captures(attrs).and_then(|c| c.get(1)).map(|m| {
232                Span::new(
233                    (attrs_start + m.start()) as u32,
234                    (attrs_start + m.end()) as u32,
235                )
236            });
237            let is_setup = SETUP_ATTR_RE.is_match(attrs);
238            // Svelte module context: Svelte 4 `context="module"` OR Svelte 5's
239            // bare `module` attribute. Both scope declarations to the module
240            // script (not the instance), so `is_template_visible_script` returns
241            // false and the instance/module split for runes harvest is correct.
242            let is_context_module =
243                CONTEXT_MODULE_ATTR_RE.is_match(attrs) || SVELTE_MODULE_ATTR_RE.is_match(attrs);
244            let generic_attr = VUE_GENERIC_ATTR_RE
245                .captures(attrs)
246                .or_else(|| SVELTE_GENERICS_ATTR_RE.captures(attrs))
247                .and_then(|cap| cap.get(1).or_else(|| cap.get(2)))
248                .map(|m| m.as_str().to_string())
249                .filter(|value| !value.trim().is_empty());
250            SfcScript {
251                body,
252                is_typescript,
253                is_jsx,
254                byte_offset,
255                src,
256                src_span,
257                is_setup,
258                is_context_module,
259                generic_attr,
260            }
261        })
262        .collect()
263}
264
265/// An extracted `<style>` block from a Vue or Svelte SFC.
266pub struct SfcStyle {
267    /// The style body text (CSS / SCSS / Sass / Less / Stylus / PostCSS source).
268    pub body: String,
269    /// The `lang` attribute value (`scss`, `sass`, `less`, `stylus`, `postcss`, ...).
270    /// `None` for plain `<style>` (CSS).
271    pub lang: Option<String>,
272    /// External style source path from the `src` attribute (`<style src="./theme.scss">`).
273    pub src: Option<String>,
274    /// Span of the `src` attribute value in the full SFC source.
275    pub src_span: Option<Span>,
276    /// Byte offset of the style body within the full SFC source.
277    pub byte_offset: usize,
278}
279
280/// A source region extracted from a larger file while preserving the byte
281/// offset of the region body in the original source.
282pub struct SourceRegion {
283    /// Region body text.
284    pub body: String,
285    /// Byte offset of `body` within the original source.
286    pub byte_offset: usize,
287}
288
289/// Extract template markup regions from a Vue/Svelte SFC.
290///
291/// The returned regions exclude `<script>` blocks, `<style>` blocks, and HTML
292/// comments, so callers can tokenize authored markup without reading code or
293/// comments as template text. Offsets always point into the original SFC source.
294#[must_use]
295pub fn extract_sfc_template_regions(source: &str) -> Vec<SourceRegion> {
296    let mut ranges: Vec<(usize, usize)> = SCRIPT_BLOCK_RE
297        .find_iter(source)
298        .chain(STYLE_BLOCK_RE.find_iter(source))
299        .chain(HTML_COMMENT_RE.find_iter(source))
300        .map(|m| (m.start(), m.end()))
301        .collect();
302    ranges.sort_unstable_by_key(|(start, _)| *start);
303    ranges_to_gaps(source, &ranges)
304}
305
306/// Extract all `<style>` blocks from a Vue/Svelte SFC source string.
307///
308/// Mirrors [`extract_sfc_scripts`]: filters blocks inside HTML comments and
309/// captures the `lang` and `src` attributes so the caller can route the body to
310/// the right preprocessor's import scanner (currently only CSS / SCSS / Sass) or
311/// seed the `src` reference as a side-effect import.
312pub fn extract_sfc_styles(source: &str) -> Vec<SfcStyle> {
313    let comment_ranges: Vec<(usize, usize)> = HTML_COMMENT_RE
314        .find_iter(source)
315        .map(|m| (m.start(), m.end()))
316        .collect();
317
318    STYLE_BLOCK_RE
319        .captures_iter(source)
320        .filter(|cap| {
321            let start = cap.get(0).map_or(0, |m| m.start());
322            !comment_ranges
323                .iter()
324                .any(|&(cs, ce)| start >= cs && start < ce)
325        })
326        .map(|cap| {
327            let attrs = cap.name("attrs").map_or("", |m| m.as_str());
328            let body = cap.name("body").map_or("", |m| m.as_str()).to_string();
329            let byte_offset = cap.name("body").map_or(0, |m| m.start());
330            let lang = LANG_ATTR_RE
331                .captures(attrs)
332                .and_then(|c| c.get(1))
333                .map(|m| m.as_str().to_string());
334            let src = SRC_ATTR_RE
335                .captures(attrs)
336                .and_then(|c| c.get(1))
337                .map(|m| m.as_str().to_string());
338            let attrs_start = cap.name("attrs").map_or(0, |m| m.start());
339            let src_span = SRC_ATTR_RE.captures(attrs).and_then(|c| c.get(1)).map(|m| {
340                Span::new(
341                    (attrs_start + m.start()) as u32,
342                    (attrs_start + m.end()) as u32,
343                )
344            });
345            SfcStyle {
346                body,
347                lang,
348                src,
349                src_span,
350                byte_offset,
351            }
352        })
353        .collect()
354}
355
356fn ranges_to_gaps(source: &str, ranges: &[(usize, usize)]) -> Vec<SourceRegion> {
357    let mut regions = Vec::new();
358    let mut cursor = 0;
359    for &(start, end) in ranges {
360        if start > cursor {
361            push_region(source, cursor, start, &mut regions);
362        }
363        cursor = cursor.max(end);
364    }
365    if cursor < source.len() {
366        push_region(source, cursor, source.len(), &mut regions);
367    }
368    regions
369}
370
371fn push_region(source: &str, start: usize, end: usize, regions: &mut Vec<SourceRegion>) {
372    let Some(body) = source.get(start..end) else {
373        return;
374    };
375    if body.trim().is_empty() {
376        return;
377    }
378    regions.push(SourceRegion {
379        body: body.to_string(),
380        byte_offset: start,
381    });
382}
383
384/// Check if a file path is a Vue or Svelte SFC (`.vue` or `.svelte`).
385#[must_use]
386pub fn is_sfc_file(path: &Path) -> bool {
387    path.extension()
388        .and_then(|e| e.to_str())
389        .is_some_and(|ext| ext == "vue" || ext == "svelte")
390}
391
392/// Parse an SFC file by extracting and combining all `<script>` and `<style>` blocks.
393pub(crate) fn parse_sfc_to_module(
394    file_id: FileId,
395    path: &Path,
396    source: &str,
397    content_hash: u64,
398    need_complexity: bool,
399) -> ModuleInfo {
400    let scripts = extract_sfc_scripts(source);
401    let styles = extract_sfc_styles(source);
402    let kind = sfc_kind(path);
403    let mut combined = empty_sfc_module(file_id, source, content_hash);
404    let mut template_visible_imports: FxHashSet<String> = FxHashSet::default();
405    let mut template_visible_bound_targets: FxHashMap<String, String> = FxHashMap::default();
406    let mut props_return_binding: Option<String> = None;
407    let mut emit_return_binding: Option<String> = None;
408
409    for script in &scripts {
410        merge_script_into_module(&mut SfcScriptMergeInput {
411            kind,
412            script,
413            combined: &mut combined,
414            template_visible_imports: &mut template_visible_imports,
415            template_visible_bound_targets: &mut template_visible_bound_targets,
416            props_return_binding: &mut props_return_binding,
417            emit_return_binding: &mut emit_return_binding,
418            need_complexity,
419        });
420    }
421
422    for style in &styles {
423        merge_style_into_module(style, &mut combined);
424    }
425
426    // Whole-object prop/attr spread in the template (`v-bind="$attrs"`,
427    // `v-bind="$props"`, `v-bind="props"`) can consume a prop indirectly, so the
428    // `unused-component-prop` detector must abstain on the whole file.
429    if kind == SfcKind::Vue
430        && !combined.component_props.is_empty()
431        && PROPS_ATTRS_SPREAD_RE.is_match(source)
432    {
433        combined.has_props_attrs_fallthrough = true;
434    }
435
436    apply_template_usage(TemplateUsageInput {
437        kind,
438        source,
439        template_visible_imports: &template_visible_imports,
440        template_visible_bound_targets: &template_visible_bound_targets,
441        props_return_binding: props_return_binding.as_deref(),
442        credit_load_data: kind == SfcKind::Svelte && is_sveltekit_route_data_component(path),
443        combined: &mut combined,
444    });
445
446    if need_complexity {
447        append_template_complexity(kind, source, &mut combined);
448    }
449
450    // Credit `<emit_binding>('event')` / `$emit('event')` calls in the template
451    // (`@click="emit('close')"`), which the script-only emit usage walk cannot
452    // see. A dynamic template emit (`$emit(someVar)`) abstains the whole file.
453    if kind == SfcKind::Vue && !combined.component_emits.is_empty() {
454        apply_template_emit_usage(source, emit_return_binding.as_deref(), &mut combined);
455    }
456
457    // Harvest Svelte template `on:<name>` listener bindings on component tags
458    // into the per-file listened set; the `unused-svelte-event` detector unions
459    // these project-wide to decide which dispatched events are dead.
460    if kind == SfcKind::Svelte {
461        combined.svelte_listened_events =
462            crate::sfc_template::collect_svelte_listened_events(source);
463    }
464
465    append_template_asset_imports(source, &mut combined);
466    dedup_import_binding_lists(&mut combined);
467
468    combined
469}
470
471/// Append the synthetic `<template>` complexity entry for the SFC. Counts
472/// template control flow (`v-if`/`v-for`, `{#if}`/`{#each}`) and
473/// bound-expression/interpolation complexity so a template-heavy SFC is not
474/// scored as artificially simple. The scanners mask `<script>`/`<style>`/comments,
475/// so script control flow is NOT double-counted (it is scored by
476/// `translate_script_complexity`). Mirrors Angular's synthetic entry; no new rule
477/// or threshold, the entry folds into the existing complexity aggregate.
478fn append_template_complexity(kind: SfcKind, source: &str, combined: &mut ModuleInfo) {
479    let template_complexity = match kind {
480        SfcKind::Vue => crate::template_complexity::compute_vue_template_complexity(source),
481        SfcKind::Svelte => crate::template_complexity::compute_svelte_template_complexity(source),
482    };
483    combined.complexity.extend(template_complexity);
484}
485
486/// Turn static relative asset references in markup (`<img src="./logo.png">`)
487/// into `SideEffect` imports so a genuinely-missing asset surfaces as
488/// `unresolved-import` (existing assets resolve to `ExternalFile`, no finding).
489fn append_template_asset_imports(source: &str, combined: &mut ModuleInfo) {
490    for (specifier, span) in collect_template_asset_refs(source) {
491        combined.imports.push(ImportInfo {
492            source: specifier,
493            imported_name: ImportedName::SideEffect,
494            local_name: String::new(),
495            is_type_only: false,
496            from_style: false,
497            span,
498            source_span: span,
499        });
500    }
501}
502
503/// Sort and dedup the per-script import-binding accumulator lists so the merged
504/// SFC module reports each binding once in a stable order.
505fn dedup_import_binding_lists(combined: &mut ModuleInfo) {
506    combined.unused_import_bindings.sort_unstable();
507    combined.unused_import_bindings.dedup();
508    combined.type_referenced_import_bindings.sort_unstable();
509    combined.type_referenced_import_bindings.dedup();
510    combined.value_referenced_import_bindings.sort_unstable();
511    combined.value_referenced_import_bindings.dedup();
512    combined.auto_import_candidates.sort_unstable();
513    combined.auto_import_candidates.dedup();
514}
515
516fn sfc_kind(path: &Path) -> SfcKind {
517    if path.extension().and_then(|ext| ext.to_str()) == Some("vue") {
518        SfcKind::Vue
519    } else {
520        SfcKind::Svelte
521    }
522}
523
524/// SvelteKit route components receive a `data` prop populated by the route's
525/// `load()` return object. This predicate gates the `data`-as-template-root
526/// credit (unused-load-data-key Primitive B) to exactly those files. It matches
527/// `+page.svelte` / `+layout.svelte` AND their layout-reset variants
528/// (`+page@.svelte`, `+page@named.svelte`, `+page@(group).svelte`, and the
529/// `+layout@...` forms), all of which still receive the `data` prop. `+error.svelte`
530/// is excluded (it receives `$page.error`, not the `load()` `data` prop), and a
531/// non-route file like `+pageHelper.svelte` is excluded by the grammar (the part
532/// after `+page` must be empty or start with `@`). The leading `+` is a
533/// SvelteKit-only filename convention, so no ordinary `.svelte` component matches.
534fn is_sveltekit_route_data_component(path: &Path) -> bool {
535    let Some(stem) = path
536        .file_name()
537        .and_then(|name| name.to_str())
538        .and_then(|name| name.strip_suffix(".svelte"))
539    else {
540        return false;
541    };
542    ["+page", "+layout"].iter().any(|prefix| {
543        stem.strip_prefix(prefix)
544            .is_some_and(|rest| rest.is_empty() || rest.starts_with('@'))
545    })
546}
547
548fn empty_sfc_module(file_id: FileId, source: &str, content_hash: u64) -> ModuleInfo {
549    let parsed = crate::suppress::parse_suppressions_from_source(source);
550
551    crate::module_info::non_js_module_info(
552        file_id,
553        content_hash,
554        source,
555        parsed,
556        Vec::new(),
557        Vec::new(),
558    )
559}
560
561struct SfcScriptMergeInput<'a> {
562    kind: SfcKind,
563    script: &'a SfcScript,
564    combined: &'a mut ModuleInfo,
565    template_visible_imports: &'a mut FxHashSet<String>,
566    template_visible_bound_targets: &'a mut FxHashMap<String, String>,
567    props_return_binding: &'a mut Option<String>,
568    emit_return_binding: &'a mut Option<String>,
569    need_complexity: bool,
570}
571
572fn merge_script_into_module(input: &mut SfcScriptMergeInput<'_>) {
573    if input.kind == SfcKind::Vue
574        && let Some(src) = &input.script.src
575    {
576        add_script_src_import(input.combined, src, input.script.src_span);
577    }
578
579    let allocator = Allocator::default();
580    let parser_return = Parser::new(
581        &allocator,
582        &input.script.body,
583        source_type_for_script(input.script),
584    )
585    .parse();
586    let mut extractor = ModuleInfoExtractor::new();
587    extractor.visit_program(&parser_return.program);
588    let extraction = ExtractionResult::contiguous(&input.script.body, input.script.byte_offset);
589    extractor.remap_spans_with(|span| extraction.remap_span(span));
590    extractor.resolve_typed_destructure_bindings();
591
592    merge_script_binding_usage(input, &allocator, &parser_return, &extractor.imports);
593    if input.need_complexity {
594        input
595            .combined
596            .complexity
597            .extend(translate_script_complexity(
598                input.script,
599                &parser_return.program,
600                &input.combined.line_offsets,
601            ));
602    }
603
604    // Vue prop/emit harvesting (`<script setup>` macros + Options API) for the
605    // `unused-component-prop` / `unused-component-emit` detectors. Extracted to a
606    // helper to keep this function under the unit-size lint.
607    if input.kind == SfcKind::Vue {
608        merge_vue_props_emits_into(input, &parser_return.program);
609    }
610
611    // Svelte 5 `$props()` rune harvesting for `unused-component-prop`. `$props`
612    // is an instance-only rune, so harvest ONLY the template-visible instance
613    // script, never the module script (`<script context="module">` /
614    // `<script module>`).
615    if input.kind == SfcKind::Svelte && is_template_visible_script(input.kind, input.script) {
616        merge_svelte_props_into(
617            input.combined,
618            &parser_return.program,
619            input.script.byte_offset,
620        );
621    }
622
623    if is_template_visible_script(input.kind, input.script) {
624        harvest_template_visible_bindings(input, &extractor);
625    }
626
627    // Dispatched events recorded by the visitor carry body-relative spans, like
628    // props/emits above. Remap the entries this script contributes onto the SFC
629    // source via the script byte offset so the finding line/col points at the
630    // real `dispatch(...)` call, not a body-relative position.
631    let dispatch_base = input.combined.svelte_dispatched_events.len();
632    extractor.merge_into(input.combined);
633    for event in &mut input.combined.svelte_dispatched_events[dispatch_base..] {
634        event.span_start += input.script.byte_offset as u32;
635    }
636}
637
638/// Compute and merge this script's import-binding usage (unused / type- and
639/// value-referenced) plus auto-import candidates into `combined`. A
640/// `generic="..."` attribute re-parses an augmented body so a type-only import
641/// consumed solely inside the constraint stays classified as type-referenced.
642fn merge_script_binding_usage(
643    input: &mut SfcScriptMergeInput<'_>,
644    allocator: &Allocator,
645    parser_return: &oxc_parser::ParserReturn<'_>,
646    imports: &[ImportInfo],
647) {
648    let augmented_body = build_generic_attr_probe_source(input.script);
649    let empty_template_used = FxHashSet::default();
650    let (binding_usage, auto_import_candidates) = if let Some(augmented) = augmented_body.as_deref()
651    {
652        let augmented_return =
653            Parser::new(allocator, augmented, source_type_for_script(input.script)).parse();
654        (
655            compute_import_binding_usage(&augmented_return.program, imports, &empty_template_used),
656            compute_auto_import_candidates(&parser_return.program),
657        )
658    } else {
659        let semantic_usage =
660            compute_semantic_usage(&parser_return.program, imports, &empty_template_used);
661        (
662            semantic_usage.import_binding_usage,
663            semantic_usage.auto_import_candidates,
664        )
665    };
666    input
667        .combined
668        .unused_import_bindings
669        .extend(binding_usage.unused.iter().cloned());
670    input
671        .combined
672        .type_referenced_import_bindings
673        .extend(binding_usage.type_referenced.iter().cloned());
674    input
675        .combined
676        .value_referenced_import_bindings
677        .extend(binding_usage.value_referenced.iter().cloned());
678    input
679        .combined
680        .auto_import_candidates
681        .extend(auto_import_candidates);
682}
683
684/// Carry an instance script's import locals and binding-target names into the
685/// template-visible sets (dropping empty locals and `this.`-prefixed targets) so
686/// the template scanner can credit them.
687fn harvest_template_visible_bindings(
688    input: &mut SfcScriptMergeInput<'_>,
689    extractor: &ModuleInfoExtractor,
690) {
691    input.template_visible_imports.extend(
692        extractor
693            .imports
694            .iter()
695            .filter(|import| !import.local_name.is_empty())
696            .map(|import| import.local_name.clone()),
697    );
698    input.template_visible_bound_targets.extend(
699        extractor
700            .binding_target_names()
701            .iter()
702            .filter(|(local, _)| !local.starts_with("this."))
703            .map(|(local, target)| (local.clone(), target.clone())),
704    );
705}
706
707/// Harvest Svelte 5 `$props()` declared props from an instance `<script>`
708/// program into `combined.component_props` (reusing the Vue IR + abstain flags),
709/// remapping each prop's body-relative span onto the SFC source via `byte_offset`.
710fn merge_svelte_props_into(
711    combined: &mut ModuleInfo,
712    program: &oxc_ast::ast::Program<'_>,
713    byte_offset: usize,
714) {
715    let harvest = crate::sfc_props::harvest_svelte_props(program);
716    if harvest.has_unharvestable_props {
717        combined.has_unharvestable_props = true;
718    }
719    if harvest.has_props_attrs_fallthrough {
720        combined.has_props_attrs_fallthrough = true;
721    }
722    for mut prop in harvest.props {
723        prop.span_start += byte_offset as u32;
724        combined.component_props.push(prop);
725    }
726}
727
728/// Harvest Vue prop/emit declarations into `combined`, remapping body-relative
729/// spans onto the SFC source via the script byte offset. The `<script setup>`
730/// path harvests `defineProps` / `defineEmits` (and the `defineExpose` /
731/// `defineModel` abstain flags + return bindings); the non-setup path harvests
732/// the Options API `props:` / `emits:` (same IR, same abstain flags, same remap,
733/// only the harvest source differs).
734fn merge_vue_props_emits_into(
735    input: &mut SfcScriptMergeInput<'_>,
736    program: &oxc_ast::ast::Program<'_>,
737) {
738    let byte_offset = input.script.byte_offset as u32;
739    if input.script.is_setup {
740        apply_props_harvest(
741            input,
742            crate::sfc_props::harvest_define_props(program),
743            byte_offset,
744        );
745        apply_emits_harvest(
746            input,
747            crate::sfc_props::harvest_define_emits(program),
748            byte_offset,
749        );
750    } else {
751        apply_props_harvest(
752            input,
753            crate::sfc_props::harvest_options_api_props(program),
754            byte_offset,
755        );
756        apply_emits_harvest(
757            input,
758            crate::sfc_props::harvest_options_api_emits(program),
759            byte_offset,
760        );
761    }
762}
763
764/// Fold a prop harvest (setup `defineProps` or Options-API `props:`) into
765/// `combined`: copy the abstain flags and `defineProps` return binding, then push
766/// each prop with its span remapped onto the SFC source. The setup-only fields
767/// (`has_define_expose` / `has_define_model` / `props_return_binding`) default to
768/// `false`/`None` in the Options-API harvest, so the shared copy is inert there.
769fn apply_props_harvest(
770    input: &mut SfcScriptMergeInput<'_>,
771    harvest: crate::sfc_props::DefinePropsHarvest,
772    byte_offset: u32,
773) {
774    if harvest.has_unharvestable_props {
775        input.combined.has_unharvestable_props = true;
776    }
777    if harvest.has_props_attrs_fallthrough {
778        input.combined.has_props_attrs_fallthrough = true;
779    }
780    if harvest.has_define_expose {
781        input.combined.has_define_expose = true;
782    }
783    if harvest.has_define_model {
784        input.combined.has_define_model = true;
785    }
786    if let Some(binding) = harvest.props_return_binding {
787        *input.props_return_binding = Some(binding);
788    }
789    for mut prop in harvest.props {
790        prop.span_start += byte_offset;
791        input.combined.component_props.push(prop);
792    }
793}
794
795/// Fold an emit harvest (setup `defineEmits` or Options-API `emits:`) into
796/// `combined`: copy the abstain flags and emit return binding, then push each
797/// emit with its span remapped onto the SFC source. The setup-only fields
798/// (`has_emit_whole_object_use` / `emit_binding`) default to `false`/`None` in
799/// the Options-API harvest, so the shared copy is inert there.
800fn apply_emits_harvest(
801    input: &mut SfcScriptMergeInput<'_>,
802    harvest: crate::sfc_props::DefineEmitsHarvest,
803    byte_offset: u32,
804) {
805    if harvest.has_unharvestable_emits {
806        input.combined.has_unharvestable_emits = true;
807    }
808    if harvest.has_dynamic_emit {
809        input.combined.has_dynamic_emit = true;
810    }
811    if harvest.has_emit_whole_object_use {
812        input.combined.has_emit_whole_object_use = true;
813    }
814    if let Some(binding) = harvest.emit_binding {
815        *input.emit_return_binding = Some(binding);
816    }
817    for mut emit in harvest.emits {
818        emit.span_start += byte_offset;
819        input.combined.component_emits.push(emit);
820    }
821}
822
823fn translate_script_complexity(
824    script: &SfcScript,
825    program: &oxc_ast::ast::Program<'_>,
826    sfc_line_offsets: &[u32],
827) -> Vec<FunctionComplexity> {
828    let script_line_offsets = compute_line_offsets(&script.body);
829    let mut complexity =
830        crate::complexity::compute_complexity(program, &script.body, &script_line_offsets);
831    let (body_start_line, body_start_col) =
832        byte_offset_to_line_col(sfc_line_offsets, script.byte_offset as u32);
833
834    for function in &mut complexity {
835        function.line = body_start_line + function.line.saturating_sub(1);
836        if function.line == body_start_line {
837            function.col += body_start_col;
838        }
839    }
840
841    complexity
842}
843
844fn add_script_src_import(module: &mut ModuleInfo, source: &str, source_span: Option<Span>) {
845    let span = source_span.unwrap_or_default();
846    module.imports.push(ImportInfo {
847        source: normalize_asset_url(source),
848        imported_name: ImportedName::SideEffect,
849        local_name: String::new(),
850        is_type_only: false,
851        from_style: false,
852        span,
853        source_span: span,
854    });
855}
856
857/// `lang` attribute values whose body we know how to scan for `@import` /
858/// `@use` / `@forward` / `@plugin` directives. Plain `<style>` (no `lang`) is treated as
859/// CSS. `less`, `stylus`, and `postcss` bodies are NOT scanned because their
860/// import syntax differs (`@import (reference)` modifiers, etc.); their
861/// `<style src="...">` references are still seeded.
862fn style_lang_is_scss(lang: Option<&str>) -> bool {
863    matches!(lang, Some("scss" | "sass"))
864}
865
866fn style_lang_is_css_like(lang: Option<&str>) -> bool {
867    lang.is_none() || matches!(lang, Some("css"))
868}
869
870fn merge_style_into_module(style: &SfcStyle, combined: &mut ModuleInfo) {
871    if let Some(src) = &style.src {
872        let span = style.src_span.unwrap_or_default();
873        combined.imports.push(ImportInfo {
874            source: normalize_asset_url(src),
875            imported_name: ImportedName::SideEffect,
876            local_name: String::new(),
877            is_type_only: false,
878            from_style: true,
879            span,
880            source_span: span,
881        });
882    }
883
884    let lang = style.lang.as_deref();
885    let is_scss = style_lang_is_scss(lang);
886    let is_css_like = style_lang_is_css_like(lang);
887    if !is_scss && !is_css_like {
888        return;
889    }
890
891    for source in crate::css::extract_css_import_sources(&style.body, is_scss) {
892        let source_span = Span::new(
893            style.byte_offset as u32 + source.span.start,
894            style.byte_offset as u32 + source.span.end,
895        );
896        combined.imports.push(ImportInfo {
897            source: source.normalized,
898            imported_name: if source.is_plugin {
899                ImportedName::Default
900            } else {
901                ImportedName::SideEffect
902            },
903            local_name: String::new(),
904            is_type_only: false,
905            from_style: true,
906            span: source_span,
907            source_span,
908        });
909    }
910}
911
912fn source_type_for_script(script: &SfcScript) -> SourceType {
913    match (script.is_typescript, script.is_jsx) {
914        (true, true) => SourceType::tsx(),
915        (true, false) => SourceType::ts(),
916        (false, true) => SourceType::jsx(),
917        (false, false) => SourceType::mjs(),
918    }
919}
920
921/// Build an augmented script body that pins the `generic="..."` constraint as
922/// a synthetic local type alias. The alias is unexported and uses a sentinel
923/// name so it can't collide with user code. Returns `None` when there is no
924/// generic attribute to pin (the common case), so callers fall back to the
925/// raw body without paying for a second parse.
926fn build_generic_attr_probe_source(script: &SfcScript) -> Option<String> {
927    let constraint = script.generic_attr.as_deref()?.trim();
928    if constraint.is_empty() {
929        return None;
930    }
931    Some(format!(
932        "{}\n;type __FALLOW_GENERIC_ATTR_PROBE<{}> = unknown;\n",
933        script.body, constraint,
934    ))
935}
936
937struct TemplateUsageInput<'a> {
938    kind: SfcKind,
939    source: &'a str,
940    template_visible_imports: &'a FxHashSet<String>,
941    template_visible_bound_targets: &'a FxHashMap<String, String>,
942    props_return_binding: Option<&'a str>,
943    credit_load_data: bool,
944    combined: &'a mut ModuleInfo,
945}
946
947fn apply_template_usage(input: TemplateUsageInput<'_>) {
948    let TemplateUsageInput {
949        kind,
950        source,
951        template_visible_imports,
952        template_visible_bound_targets,
953        props_return_binding,
954        credit_load_data,
955        combined,
956    } = input;
957    let credited = build_template_credited_set(
958        template_visible_imports,
959        props_return_binding,
960        credit_load_data,
961        source,
962        combined,
963    );
964    let template_usage = compute_template_usage(
965        kind,
966        source,
967        &credited,
968        template_visible_bound_targets,
969        credit_load_data,
970    );
971    apply_prop_template_credit(&template_usage, props_return_binding, combined);
972    merge_template_usage_into_combined(template_usage, combined);
973}
974
975/// Build the set of template-credited names: the template-visible imports plus
976/// each harvested prop name / destructure local, Vue's implicit `$props`, the
977/// `defineProps` return binding, and (for SvelteKit route components) the `data`
978/// load prop. Crediting a prop name against an import is inert. Also sets
979/// `has_load_data_whole_use` when a route spreads / passes the whole `data` prop.
980fn build_template_credited_set(
981    template_visible_imports: &FxHashSet<String>,
982    props_return_binding: Option<&str>,
983    credit_load_data: bool,
984    source: &str,
985    combined: &mut ModuleInfo,
986) -> FxHashSet<String> {
987    let mut credited: FxHashSet<String> = template_visible_imports.clone();
988    // unused-load-data-key Primitive B: a SvelteKit route component receives a
989    // `data` prop populated by the route's `load()` return object. Credit `data`
990    // as a recognized root so its template member accesses (`data.<key>`) are
991    // emitted for the cross-file load-data-key join, gated to route components.
992    if credit_load_data {
993        credited.insert("data".to_string());
994        // FP-1: a route component spreading / passing the whole `data` prop in
995        // markup consumes arbitrary keys opaquely; force the detector to abstain.
996        if SVELTE_TEMPLATE_DATA_WHOLE_USE_RE.is_match(source) {
997            combined.has_load_data_whole_use = true;
998        }
999    }
1000    if !combined.component_props.is_empty() {
1001        for prop in &combined.component_props {
1002            // Credit both the declared name (Vue exposes props by name in the
1003            // template) and the destructure local (a renamed prop is used via it).
1004            credited.insert(prop.name.clone());
1005            credited.insert(prop.local.clone());
1006        }
1007        // Vue's implicit `$props` whole-props object is always available in a
1008        // template; credit `$props.<name>` member accesses too.
1009        credited.insert("$props".to_string());
1010        if let Some(binding) = props_return_binding {
1011            credited.insert(binding.to_string());
1012        }
1013    }
1014    credited
1015}
1016
1017/// Scan the template for usage of the credited names and bound targets. For a
1018/// SvelteKit route, `data` is dropped from the bound targets so its template
1019/// member accesses stay keyed on `data` (not remapped onto the generated
1020/// `PageData` / `LayoutData` type) for the cross-file load-data join.
1021fn compute_template_usage(
1022    kind: SfcKind,
1023    source: &str,
1024    credited: &FxHashSet<String>,
1025    template_visible_bound_targets: &FxHashMap<String, String>,
1026    credit_load_data: bool,
1027) -> crate::template_usage::TemplateUsage {
1028    if credit_load_data && template_visible_bound_targets.contains_key("data") {
1029        let mut filtered = template_visible_bound_targets.clone();
1030        filtered.remove("data");
1031        collect_template_usage_with_bound_targets(kind, source, credited, &filtered)
1032    } else {
1033        collect_template_usage_with_bound_targets(
1034            kind,
1035            source,
1036            credited,
1037            template_visible_bound_targets,
1038        )
1039    }
1040}
1041
1042/// Mark each harvested prop `used_in_template` when the template references it by
1043/// bare name (destructure form) or via a `<props>.<name>` / `$props.<name>`
1044/// member access. A bare reference to a custom `defineProps` return binding as a
1045/// whole object means abstain on the whole file (`has_props_attrs_fallthrough`).
1046fn apply_prop_template_credit(
1047    template_usage: &crate::template_usage::TemplateUsage,
1048    props_return_binding: Option<&str>,
1049    combined: &mut ModuleInfo,
1050) {
1051    if !combined.component_props.is_empty() {
1052        let member_used: FxHashSet<&str> = template_usage
1053            .member_accesses
1054            .iter()
1055            .filter(|access| {
1056                access.object == "$props"
1057                    || props_return_binding.is_some_and(|binding| access.object == binding)
1058            })
1059            .map(|access| access.member.as_str())
1060            .collect();
1061        for prop in &mut combined.component_props {
1062            if template_usage.used_bindings.contains(&prop.name)
1063                || template_usage.used_bindings.contains(&prop.local)
1064                || member_used.contains(prop.name.as_str())
1065            {
1066                prop.used_in_template = true;
1067            }
1068        }
1069    }
1070
1071    if let Some(binding) = props_return_binding
1072        && (template_usage.used_bindings.contains(binding)
1073            || template_usage
1074                .whole_object_uses
1075                .iter()
1076                .any(|used| used == binding))
1077    {
1078        combined.has_props_attrs_fallthrough = true;
1079    }
1080}
1081
1082/// Drain the scanned template usage into `combined`: retain unused-import
1083/// bindings the template did not consume, extend member accesses / whole-object
1084/// uses / security sinks, and fold unresolved tag names into auto-import
1085/// candidates (sorted + deduped).
1086fn merge_template_usage_into_combined(
1087    template_usage: crate::template_usage::TemplateUsage,
1088    combined: &mut ModuleInfo,
1089) {
1090    combined
1091        .unused_import_bindings
1092        .retain(|binding| !template_usage.used_bindings.contains(binding));
1093    combined
1094        .member_accesses
1095        .extend(template_usage.member_accesses);
1096    combined
1097        .whole_object_uses
1098        .extend(template_usage.whole_object_uses);
1099    combined
1100        .security_sinks
1101        .extend(template_usage.security_sinks);
1102    if !template_usage.unresolved_tag_names.is_empty() {
1103        let mut names: Vec<String> = template_usage.unresolved_tag_names.into_iter().collect();
1104        names.sort_unstable();
1105        combined.auto_import_candidates.extend(names);
1106        combined.auto_import_candidates.dedup();
1107    }
1108}
1109
1110/// Credit emit events fired from the `<template>` (`@click="emit('close')"`,
1111/// `@click="$emit('remove')"`, `:close="{ onClick: () => emit('close') }"`),
1112/// which the script-only emit usage walk in `harvest_define_emits` cannot see.
1113///
1114/// Scans the template-only region (scripts/styles/comments masked) for
1115/// [`TEMPLATE_EMIT_CALL_RE`]: a call whose callee is the harvested emit binding
1116/// (`emit` / `emits` / whatever it was bound to) or the implicit `$emit` (always
1117/// available in a Vue template regardless of `<script setup>` binding). A
1118/// string-literal first arg credits the matching `ComponentEmit` as used; a
1119/// non-literal first arg (a variable / template-literal) is a dynamic template
1120/// emit whose event is unknowable, so the whole file abstains (`has_dynamic_emit`)
1121/// to preserve the zero-FP doctrine.
1122///
1123/// Over-crediting is the safe direction (it only suppresses a finding), so a
1124/// liberal raw-source scan is intentional here. The scan is byte-safe: the regex
1125/// runs over the `&str` template and only reads captured-group text, never
1126/// slicing at arbitrary byte offsets.
1127fn apply_template_emit_usage(
1128    source: &str,
1129    emit_return_binding: Option<&str>,
1130    combined: &mut ModuleInfo,
1131) {
1132    let masked = mask_non_markup_regions(source);
1133    let mut used: FxHashSet<String> = FxHashSet::default();
1134    let mut dynamic = false;
1135
1136    for caps in TEMPLATE_EMIT_CALL_RE.captures_iter(&masked) {
1137        let Some(callee) = caps.get(1) else {
1138            continue;
1139        };
1140        let callee = callee.as_str();
1141        let is_emit_call =
1142            callee == "$emit" || emit_return_binding.is_some_and(|binding| callee == binding);
1143        if !is_emit_call {
1144            continue;
1145        }
1146        if let Some(event) = caps.get(2).or_else(|| caps.get(3)) {
1147            // String-literal first arg (single- or double-quoted): the event
1148            // name. Credit it as used.
1149            used.insert(event.as_str().to_string());
1150        } else if caps.get(4).is_some() {
1151            // Non-literal first arg (`$emit(someVar)`, `emit(\`x\`)`): the event
1152            // cannot be known. Abstain on the whole file.
1153            dynamic = true;
1154        }
1155    }
1156
1157    if dynamic {
1158        combined.has_dynamic_emit = true;
1159    }
1160    if !used.is_empty() {
1161        for emit in &mut combined.component_emits {
1162            if used.contains(&emit.name) {
1163                emit.used = true;
1164            }
1165        }
1166    }
1167}
1168
1169fn is_template_visible_script(kind: SfcKind, script: &SfcScript) -> bool {
1170    match kind {
1171        SfcKind::Vue => script.is_setup,
1172        SfcKind::Svelte => !script.is_context_module,
1173    }
1174}
1175
1176#[cfg(all(test, not(miri)))]
1177mod tests {
1178    use super::*;
1179
1180    #[test]
1181    fn is_sfc_file_vue() {
1182        assert!(is_sfc_file(Path::new("App.vue")));
1183    }
1184
1185    #[test]
1186    fn is_sfc_file_svelte() {
1187        assert!(is_sfc_file(Path::new("Counter.svelte")));
1188    }
1189
1190    #[test]
1191    fn is_sfc_file_rejects_ts() {
1192        assert!(!is_sfc_file(Path::new("utils.ts")));
1193    }
1194
1195    #[test]
1196    fn is_sfc_file_rejects_jsx() {
1197        assert!(!is_sfc_file(Path::new("App.jsx")));
1198    }
1199
1200    #[test]
1201    fn is_sfc_file_rejects_astro() {
1202        assert!(!is_sfc_file(Path::new("Layout.astro")));
1203    }
1204
1205    #[test]
1206    fn single_plain_script() {
1207        let scripts = extract_sfc_scripts("<script>const x = 1;</script>");
1208        assert_eq!(scripts.len(), 1);
1209        assert_eq!(scripts[0].body, "const x = 1;");
1210        assert!(!scripts[0].is_typescript);
1211        assert!(!scripts[0].is_jsx);
1212        assert!(scripts[0].src.is_none());
1213    }
1214
1215    #[test]
1216    fn single_ts_script() {
1217        let scripts = extract_sfc_scripts(r#"<script lang="ts">const x: number = 1;</script>"#);
1218        assert_eq!(scripts.len(), 1);
1219        assert!(scripts[0].is_typescript);
1220        assert!(!scripts[0].is_jsx);
1221    }
1222
1223    #[test]
1224    fn single_tsx_script() {
1225        let scripts = extract_sfc_scripts(r#"<script lang="tsx">const el = <div />;</script>"#);
1226        assert_eq!(scripts.len(), 1);
1227        assert!(scripts[0].is_typescript);
1228        assert!(scripts[0].is_jsx);
1229    }
1230
1231    #[test]
1232    fn single_jsx_script() {
1233        let scripts = extract_sfc_scripts(r#"<script lang="jsx">const el = <div />;</script>"#);
1234        assert_eq!(scripts.len(), 1);
1235        assert!(!scripts[0].is_typescript);
1236        assert!(scripts[0].is_jsx);
1237    }
1238
1239    #[test]
1240    fn two_script_blocks() {
1241        let source = r#"
1242<script lang="ts">
1243export default {};
1244</script>
1245<script setup lang="ts">
1246const count = 0;
1247</script>
1248"#;
1249        let scripts = extract_sfc_scripts(source);
1250        assert_eq!(scripts.len(), 2);
1251        assert!(scripts[0].body.contains("export default"));
1252        assert!(scripts[1].body.contains("count"));
1253    }
1254
1255    #[test]
1256    fn script_setup_extracted() {
1257        let scripts =
1258            extract_sfc_scripts(r#"<script setup lang="ts">import { ref } from 'vue';</script>"#);
1259        assert_eq!(scripts.len(), 1);
1260        assert!(scripts[0].body.contains("import"));
1261        assert!(scripts[0].is_typescript);
1262    }
1263
1264    #[test]
1265    fn script_src_detected() {
1266        let scripts = extract_sfc_scripts(r#"<script src="./component.ts" lang="ts"></script>"#);
1267        assert_eq!(scripts.len(), 1);
1268        assert_eq!(scripts[0].src.as_deref(), Some("./component.ts"));
1269    }
1270
1271    // -- Svelte module-context recognition (W1.1 piece 1) ----------------------
1272
1273    #[test]
1274    fn svelte4_context_module_is_module_context() {
1275        let scripts =
1276            extract_sfc_scripts(r#"<script context="module">export const x = 1;</script>"#);
1277        assert_eq!(scripts.len(), 1);
1278        assert!(scripts[0].is_context_module);
1279    }
1280
1281    #[test]
1282    fn svelte5_bare_module_attr_is_module_context() {
1283        let scripts = extract_sfc_scripts(r"<script module>export const x = 1;</script>");
1284        assert_eq!(scripts.len(), 1);
1285        assert!(scripts[0].is_context_module);
1286    }
1287
1288    #[test]
1289    fn svelte5_module_with_lang_is_module_context() {
1290        let scripts =
1291            extract_sfc_scripts(r#"<script module lang="ts">export const x = 1;</script>"#);
1292        assert_eq!(scripts.len(), 1);
1293        assert!(scripts[0].is_context_module);
1294        assert!(scripts[0].is_typescript);
1295    }
1296
1297    #[test]
1298    fn plain_script_is_not_module_context() {
1299        let scripts = extract_sfc_scripts(r"<script>const x = 1;</script>");
1300        assert_eq!(scripts.len(), 1);
1301        assert!(!scripts[0].is_context_module);
1302    }
1303
1304    #[test]
1305    fn lang_ts_script_is_not_module_context() {
1306        let scripts = extract_sfc_scripts(r#"<script lang="ts">const x = 1;</script>"#);
1307        assert_eq!(scripts.len(), 1);
1308        assert!(!scripts[0].is_context_module);
1309    }
1310
1311    #[test]
1312    fn data_module_attr_is_not_module_context() {
1313        // The `(?:^|\s)module(?:\s|$|=)` anchor must not match `data-module`.
1314        let scripts =
1315            extract_sfc_scripts(r#"<script data-module="x" lang="ts">const x = 1;</script>"#);
1316        assert_eq!(scripts.len(), 1);
1317        assert!(!scripts[0].is_context_module);
1318    }
1319
1320    #[test]
1321    fn bare_module_script_is_not_template_visible() {
1322        // AC-2: a bare `<script module>` is scoped as module context, so its
1323        // imports are NOT credited as template-visible (matching `context="module"`).
1324        let module_script = SfcScript {
1325            body: String::new(),
1326            is_typescript: false,
1327            is_jsx: false,
1328            byte_offset: 0,
1329            src: None,
1330            src_span: None,
1331            is_setup: false,
1332            is_context_module: true,
1333            generic_attr: None,
1334        };
1335        assert!(!is_template_visible_script(SfcKind::Svelte, &module_script));
1336        let instance_script = SfcScript {
1337            is_context_module: false,
1338            ..module_script
1339        };
1340        assert!(is_template_visible_script(
1341            SfcKind::Svelte,
1342            &instance_script
1343        ));
1344    }
1345
1346    #[test]
1347    fn data_src_not_treated_as_src() {
1348        let scripts =
1349            extract_sfc_scripts(r#"<script lang="ts" data-src="./nope.ts">const x = 1;</script>"#);
1350        assert_eq!(scripts.len(), 1);
1351        assert!(scripts[0].src.is_none());
1352    }
1353
1354    #[test]
1355    fn script_inside_html_comment_filtered() {
1356        let source = r#"
1357<!-- <script lang="ts">import { bad } from 'bad';</script> -->
1358<script lang="ts">import { good } from 'good';</script>
1359"#;
1360        let scripts = extract_sfc_scripts(source);
1361        assert_eq!(scripts.len(), 1);
1362        assert!(scripts[0].body.contains("good"));
1363    }
1364
1365    #[test]
1366    fn spanning_comment_filters_script() {
1367        let source = r#"
1368<!-- disabled:
1369<script lang="ts">import { bad } from 'bad';</script>
1370-->
1371<script lang="ts">const ok = true;</script>
1372"#;
1373        let scripts = extract_sfc_scripts(source);
1374        assert_eq!(scripts.len(), 1);
1375        assert!(scripts[0].body.contains("ok"));
1376    }
1377
1378    #[test]
1379    fn string_containing_comment_markers_not_corrupted() {
1380        let source = r#"
1381<script setup lang="ts">
1382const marker = "<!-- not a comment -->";
1383import { ref } from 'vue';
1384</script>
1385"#;
1386        let scripts = extract_sfc_scripts(source);
1387        assert_eq!(scripts.len(), 1);
1388        assert!(scripts[0].body.contains("import"));
1389    }
1390
1391    #[test]
1392    fn generic_attr_with_angle_bracket() {
1393        let source =
1394            r#"<script setup lang="ts" generic="T extends Foo<Bar>">const x = 1;</script>"#;
1395        let scripts = extract_sfc_scripts(source);
1396        assert_eq!(scripts.len(), 1);
1397        assert_eq!(scripts[0].body, "const x = 1;");
1398    }
1399
1400    #[test]
1401    fn nested_generic_attr() {
1402        let source = r#"<script setup lang="ts" generic="T extends Map<string, Set<number>>">const x = 1;</script>"#;
1403        let scripts = extract_sfc_scripts(source);
1404        assert_eq!(scripts.len(), 1);
1405        assert_eq!(scripts[0].body, "const x = 1;");
1406    }
1407
1408    #[test]
1409    fn lang_single_quoted() {
1410        let scripts = extract_sfc_scripts("<script lang='ts'>const x = 1;</script>");
1411        assert_eq!(scripts.len(), 1);
1412        assert!(scripts[0].is_typescript);
1413    }
1414
1415    #[test]
1416    fn uppercase_script_tag() {
1417        let scripts = extract_sfc_scripts(r#"<SCRIPT lang="ts">const x = 1;</SCRIPT>"#);
1418        assert_eq!(scripts.len(), 1);
1419        assert!(scripts[0].is_typescript);
1420    }
1421
1422    #[test]
1423    fn no_script_block() {
1424        let scripts = extract_sfc_scripts("<template><div>Hello</div></template>");
1425        assert!(scripts.is_empty());
1426    }
1427
1428    #[test]
1429    fn empty_script_body() {
1430        let scripts = extract_sfc_scripts(r#"<script lang="ts"></script>"#);
1431        assert_eq!(scripts.len(), 1);
1432        assert!(scripts[0].body.is_empty());
1433    }
1434
1435    #[test]
1436    fn whitespace_only_script() {
1437        let scripts = extract_sfc_scripts("<script lang=\"ts\">\n  \n</script>");
1438        assert_eq!(scripts.len(), 1);
1439        assert!(scripts[0].body.trim().is_empty());
1440    }
1441
1442    #[test]
1443    fn byte_offset_is_set() {
1444        let source = r#"<template><div/></template><script lang="ts">code</script>"#;
1445        let scripts = extract_sfc_scripts(source);
1446        assert_eq!(scripts.len(), 1);
1447        let offset = scripts[0].byte_offset;
1448        assert_eq!(&source[offset..offset + 4], "code");
1449    }
1450
1451    #[test]
1452    fn script_with_extra_attributes() {
1453        let scripts = extract_sfc_scripts(
1454            r#"<script lang="ts" id="app" type="module" data-custom="val">const x = 1;</script>"#,
1455        );
1456        assert_eq!(scripts.len(), 1);
1457        assert!(scripts[0].is_typescript);
1458        assert!(scripts[0].src.is_none());
1459    }
1460
1461    #[test]
1462    fn multiple_script_blocks_exports_combined() {
1463        let source = r#"
1464<script lang="ts">
1465export const version = '1.0';
1466</script>
1467<script setup lang="ts">
1468import { ref } from 'vue';
1469const count = ref(0);
1470</script>
1471"#;
1472        let info = parse_sfc_to_module(FileId(0), Path::new("Dual.vue"), source, 0, false);
1473        assert!(
1474            info.exports
1475                .iter()
1476                .any(|e| matches!(&e.name, crate::ExportName::Named(n) if n == "version")),
1477            "export from <script> block should be extracted"
1478        );
1479        assert!(
1480            info.imports.iter().any(|i| i.source == "vue"),
1481            "import from <script setup> block should be extracted"
1482        );
1483    }
1484
1485    #[test]
1486    fn lang_tsx_detected_as_typescript_jsx() {
1487        let scripts =
1488            extract_sfc_scripts(r#"<script lang="tsx">const el = <div>{x}</div>;</script>"#);
1489        assert_eq!(scripts.len(), 1);
1490        assert!(scripts[0].is_typescript, "lang=tsx should be typescript");
1491        assert!(scripts[0].is_jsx, "lang=tsx should be jsx");
1492    }
1493
1494    #[test]
1495    fn multiline_html_comment_filters_all_script_blocks_inside() {
1496        let source = r#"
1497<!--
1498  This whole section is disabled:
1499  <script lang="ts">import { bad1 } from 'bad1';</script>
1500  <script lang="ts">import { bad2 } from 'bad2';</script>
1501-->
1502<script lang="ts">import { good } from 'good';</script>
1503"#;
1504        let scripts = extract_sfc_scripts(source);
1505        assert_eq!(scripts.len(), 1);
1506        assert!(scripts[0].body.contains("good"));
1507    }
1508
1509    #[test]
1510    fn script_src_generates_side_effect_import() {
1511        let info = parse_sfc_to_module(
1512            FileId(0),
1513            Path::new("External.vue"),
1514            r#"<script src="./external-logic.ts" lang="ts"></script>"#,
1515            0,
1516            false,
1517        );
1518        assert!(
1519            info.imports
1520                .iter()
1521                .any(|i| i.source == "./external-logic.ts"
1522                    && matches!(i.imported_name, ImportedName::SideEffect)),
1523            "script src should generate a side-effect import"
1524        );
1525    }
1526
1527    #[test]
1528    fn parse_sfc_no_script_returns_empty_module() {
1529        let info = parse_sfc_to_module(
1530            FileId(0),
1531            Path::new("Empty.vue"),
1532            "<template><div>Hello</div></template>",
1533            42,
1534            false,
1535        );
1536        assert!(info.imports.is_empty());
1537        assert!(info.exports.is_empty());
1538        assert_eq!(info.content_hash, 42);
1539        assert_eq!(info.file_id, FileId(0));
1540    }
1541
1542    #[test]
1543    fn parse_sfc_has_line_offsets() {
1544        let info = parse_sfc_to_module(
1545            FileId(0),
1546            Path::new("LineOffsets.vue"),
1547            r#"<script lang="ts">const x = 1;</script>"#,
1548            0,
1549            false,
1550        );
1551        assert!(!info.line_offsets.is_empty());
1552    }
1553
1554    #[test]
1555    fn parse_sfc_has_suppressions() {
1556        let info = parse_sfc_to_module(
1557            FileId(0),
1558            Path::new("Suppressions.vue"),
1559            r#"<script lang="ts">
1560// fallow-ignore-file
1561export const foo = 1;
1562</script>"#,
1563            0,
1564            false,
1565        );
1566        assert!(!info.suppressions.is_empty());
1567    }
1568
1569    #[test]
1570    fn source_type_jsx_detection() {
1571        let scripts = extract_sfc_scripts(r#"<script lang="jsx">const el = <div />;</script>"#);
1572        assert_eq!(scripts.len(), 1);
1573        assert!(!scripts[0].is_typescript);
1574        assert!(scripts[0].is_jsx);
1575    }
1576
1577    #[test]
1578    fn source_type_plain_js_detection() {
1579        let scripts = extract_sfc_scripts("<script>const x = 1;</script>");
1580        assert_eq!(scripts.len(), 1);
1581        assert!(!scripts[0].is_typescript);
1582        assert!(!scripts[0].is_jsx);
1583    }
1584
1585    #[test]
1586    fn is_sfc_file_rejects_no_extension() {
1587        assert!(!is_sfc_file(Path::new("Makefile")));
1588    }
1589
1590    #[test]
1591    fn is_sfc_file_rejects_mdx() {
1592        assert!(!is_sfc_file(Path::new("post.mdx")));
1593    }
1594
1595    #[test]
1596    fn is_sfc_file_rejects_css() {
1597        assert!(!is_sfc_file(Path::new("styles.css")));
1598    }
1599
1600    #[test]
1601    fn multiple_script_blocks_both_have_offsets() {
1602        let source = r#"<script lang="ts">const a = 1;</script>
1603<script setup lang="ts">const b = 2;</script>"#;
1604        let scripts = extract_sfc_scripts(source);
1605        assert_eq!(scripts.len(), 2);
1606        let offset0 = scripts[0].byte_offset;
1607        let offset1 = scripts[1].byte_offset;
1608        assert_eq!(
1609            &source[offset0..offset0 + "const a = 1;".len()],
1610            "const a = 1;"
1611        );
1612        assert_eq!(
1613            &source[offset1..offset1 + "const b = 2;".len()],
1614            "const b = 2;"
1615        );
1616    }
1617
1618    #[test]
1619    fn script_with_src_and_lang() {
1620        let scripts = extract_sfc_scripts(r#"<script src="./logic.ts" lang="tsx"></script>"#);
1621        assert_eq!(scripts.len(), 1);
1622        assert_eq!(scripts[0].src.as_deref(), Some("./logic.ts"));
1623        assert!(scripts[0].is_typescript);
1624        assert!(scripts[0].is_jsx);
1625    }
1626
1627    #[test]
1628    fn extract_style_block_lang_scss() {
1629        let source = r#"<template/><style lang="scss">@import 'Foo';</style>"#;
1630        let styles = extract_sfc_styles(source);
1631        assert_eq!(styles.len(), 1);
1632        assert_eq!(styles[0].lang.as_deref(), Some("scss"));
1633        assert!(styles[0].body.contains("@import"));
1634        assert!(styles[0].src.is_none());
1635    }
1636
1637    #[test]
1638    fn extract_style_block_with_src() {
1639        let source = r#"<style src="./theme.scss" lang="scss"></style>"#;
1640        let styles = extract_sfc_styles(source);
1641        assert_eq!(styles.len(), 1);
1642        assert_eq!(styles[0].src.as_deref(), Some("./theme.scss"));
1643        assert_eq!(styles[0].lang.as_deref(), Some("scss"));
1644    }
1645
1646    #[test]
1647    fn extract_style_block_plain_no_lang() {
1648        let source = r"<style>.foo { color: red; }</style>";
1649        let styles = extract_sfc_styles(source);
1650        assert_eq!(styles.len(), 1);
1651        assert!(styles[0].lang.is_none());
1652    }
1653
1654    #[test]
1655    fn extract_multiple_style_blocks() {
1656        let source = r#"<style lang="scss">@import 'a';</style>
1657<style scoped lang="scss">@import 'b';</style>"#;
1658        let styles = extract_sfc_styles(source);
1659        assert_eq!(styles.len(), 2);
1660    }
1661
1662    #[test]
1663    fn style_block_inside_html_comment_filtered() {
1664        let source = r#"<!-- <style lang="scss">@import 'bad';</style> -->
1665<style lang="scss">@import 'good';</style>"#;
1666        let styles = extract_sfc_styles(source);
1667        assert_eq!(styles.len(), 1);
1668        assert!(styles[0].body.contains("good"));
1669    }
1670
1671    #[test]
1672    fn parse_sfc_extracts_style_imports_with_from_style_flag() {
1673        let info = parse_sfc_to_module(
1674            FileId(0),
1675            Path::new("Foo.vue"),
1676            r#"<template/><style lang="scss">@import 'Foo';</style>"#,
1677            0,
1678            false,
1679        );
1680        let style_import = info
1681            .imports
1682            .iter()
1683            .find(|i| i.source == "./Foo")
1684            .expect("scss @import 'Foo' should be normalized to ./Foo");
1685        assert!(
1686            style_import.from_style,
1687            "imports from <style> blocks must carry from_style=true so the resolver \
1688             enables SCSS partial fallback for the SFC importer"
1689        );
1690        assert!(matches!(
1691            style_import.imported_name,
1692            ImportedName::SideEffect
1693        ));
1694    }
1695
1696    #[test]
1697    fn parse_sfc_extracts_style_plugin_as_default_import() {
1698        let info = parse_sfc_to_module(
1699            FileId(0),
1700            Path::new("Foo.vue"),
1701            r#"<template/><style>@plugin "./tailwind-plugin.js";</style>"#,
1702            0,
1703            false,
1704        );
1705        let plugin_import = info
1706            .imports
1707            .iter()
1708            .find(|i| i.source == "./tailwind-plugin.js")
1709            .expect("style @plugin should create an import");
1710        assert!(plugin_import.from_style);
1711        assert!(matches!(plugin_import.imported_name, ImportedName::Default));
1712    }
1713
1714    #[test]
1715    fn parse_sfc_extracts_style_src_with_from_style_flag() {
1716        let info = parse_sfc_to_module(
1717            FileId(0),
1718            Path::new("Bar.vue"),
1719            r#"<style src="./Bar.scss" lang="scss"></style>"#,
1720            0,
1721            false,
1722        );
1723        let style_src = info
1724            .imports
1725            .iter()
1726            .find(|i| i.source == "./Bar.scss")
1727            .expect("<style src=\"./Bar.scss\"> should produce a side-effect import");
1728        assert!(style_src.from_style);
1729    }
1730
1731    #[test]
1732    fn parse_sfc_skips_unsupported_style_lang_body_but_keeps_src() {
1733        let info = parse_sfc_to_module(
1734            FileId(0),
1735            Path::new("Baz.vue"),
1736            r#"<style lang="postcss" src="./Baz.pcss">@custom-rule "skipped";</style>"#,
1737            0,
1738            false,
1739        );
1740        assert!(
1741            info.imports.iter().any(|i| i.source == "./Baz.pcss"),
1742            "src reference should still be seeded for unsupported lang"
1743        );
1744        assert!(
1745            !info.imports.iter().any(|i| i.source.contains("skipped")),
1746            "postcss body should not be scanned for @import directives"
1747        );
1748    }
1749
1750    fn asset_refs(source: &str) -> Vec<String> {
1751        super::collect_template_asset_refs(source)
1752            .into_iter()
1753            .map(|(s, _)| s)
1754            .collect()
1755    }
1756
1757    #[test]
1758    fn captures_static_relative_template_asset_refs() {
1759        assert_eq!(
1760            asset_refs(r#"<template><img src="./logo.png" /></template>"#),
1761            vec!["./logo.png".to_string()]
1762        );
1763        assert_eq!(
1764            asset_refs(r#"<source src="../media/clip.mp4">"#),
1765            vec!["../media/clip.mp4".to_string()]
1766        );
1767        assert_eq!(
1768            asset_refs(r#"<video poster="./thumb.jpg"></video>"#),
1769            vec!["./thumb.jpg".to_string()]
1770        );
1771    }
1772
1773    #[test]
1774    fn skips_dynamic_alias_root_remote_and_query_asset_refs() {
1775        // Dynamic bindings (Vue `:src`, `v-bind:src`, Svelte `bind:src` / `src={}`).
1776        assert!(asset_refs(r#"<img :src="logo" />"#).is_empty());
1777        assert!(asset_refs(r#"<img v-bind:src="logo" />"#).is_empty());
1778        assert!(asset_refs(r#"<img bind:src="logo" />"#).is_empty());
1779        assert!(asset_refs(r"<img src={logo} />").is_empty());
1780        assert!(asset_refs(r#"<img data-src="./x.png" />"#).is_empty());
1781        // Alias-prefixed, root-relative, remote, bare: not plain relative literals.
1782        assert!(asset_refs(r#"<img src="@/assets/x.png" />"#).is_empty());
1783        assert!(asset_refs(r#"<img src="/logo.png" />"#).is_empty());
1784        assert!(asset_refs(r#"<img src="https://cdn/x.png" />"#).is_empty());
1785        // Query / hash suffix abstains (the resolver cannot verify them).
1786        assert!(asset_refs(r#"<img src="./x.png?inline" />"#).is_empty());
1787        // Interpolated value abstains.
1788        assert!(asset_refs(r#"<img src="{{ logo }}" />"#).is_empty());
1789    }
1790
1791    #[test]
1792    fn skips_custom_component_src_prop() {
1793        // A custom component's `src` PROP must never be read as an asset edge.
1794        assert!(asset_refs(r#"<MyImage src="./x.png" />"#).is_empty());
1795        assert!(asset_refs(r#"<AppIcon src="../icons/y.svg" />"#).is_empty());
1796    }
1797
1798    #[test]
1799    fn skips_asset_refs_inside_script_style_and_comments() {
1800        // Masked regions must not contribute asset refs.
1801        assert!(asset_refs(r#"<script>const x = "<img src='./a.png'>"</script>"#).is_empty());
1802        assert!(asset_refs(r#"<style>/* <img src="./b.png"> */ .x{}</style>"#).is_empty());
1803        assert!(asset_refs(r#"<!-- <img src="./c.png" /> -->"#).is_empty());
1804    }
1805
1806    #[test]
1807    fn parse_sfc_emits_template_asset_as_side_effect_import() {
1808        let info = parse_sfc_to_module(
1809            FileId(0),
1810            Path::new("Hero.vue"),
1811            r#"<template><img src="./hero.png" /></template><script>let x=1</script>"#,
1812            0,
1813            false,
1814        );
1815        assert!(
1816            info.imports.iter().any(|i| i.source == "./hero.png"
1817                && matches!(i.imported_name, ImportedName::SideEffect)
1818                && !i.from_style),
1819            "template <img src> should seed a SideEffect import: {:?}",
1820            info.imports
1821        );
1822    }
1823
1824    // -- Svelte 5 `$props()` rune harvest (W1.1 piece 2) -----------------------
1825
1826    fn svelte_props(source: &str) -> Vec<crate::ModuleInfo> {
1827        vec![parse_sfc_to_module(
1828            FileId(0),
1829            Path::new("Component.svelte"),
1830            source,
1831            0,
1832            false,
1833        )]
1834    }
1835
1836    fn prop_names(info: &crate::ModuleInfo) -> Vec<String> {
1837        let mut names: Vec<String> = info
1838            .component_props
1839            .iter()
1840            .map(|p| p.name.clone())
1841            .collect();
1842        names.sort();
1843        names
1844    }
1845
1846    #[test]
1847    fn svelte_shorthand_props_harvested() {
1848        // AC-3: `let { a, b } = $props()` harvests `a`, `b` with `local == name`.
1849        let info = &svelte_props(r"<script>let { a, b } = $props();</script>")[0];
1850        assert_eq!(prop_names(info), vec!["a", "b"]);
1851        for prop in &info.component_props {
1852            assert_eq!(prop.local, prop.name);
1853        }
1854    }
1855
1856    #[test]
1857    fn svelte_renamed_prop_tracks_local_and_script_use() {
1858        // AC-4: `let { a: alias } = $props()` harvests `a` with `local == "alias"`,
1859        // and a reference to `alias` sets `used_in_script` for prop `a`.
1860        let info =
1861            &svelte_props(r"<script>let { a: alias } = $props(); console.log(alias);</script>")[0];
1862        assert_eq!(prop_names(info), vec!["a"]);
1863        let prop = &info.component_props[0];
1864        assert_eq!(prop.local, "alias");
1865        assert!(
1866            prop.used_in_script,
1867            "alias is referenced, so a is used in script"
1868        );
1869    }
1870
1871    #[test]
1872    fn svelte_unreferenced_prop_is_unused_in_script() {
1873        let info = &svelte_props(r"<script>let { a } = $props();</script>")[0];
1874        assert_eq!(prop_names(info), vec!["a"]);
1875        assert!(!info.component_props[0].used_in_script);
1876    }
1877
1878    #[test]
1879    fn svelte_default_prop_peeled() {
1880        // AC-5: `let { a = 1 } = $props()` harvests `a` (default peeled).
1881        let info = &svelte_props(r"<script>let { a = 1 } = $props();</script>")[0];
1882        assert_eq!(prop_names(info), vec!["a"]);
1883    }
1884
1885    #[test]
1886    fn svelte_bindable_default_peeled() {
1887        // The bindable form `let { a = $bindable() } = $props()`: `a` is still a
1888        // declared prop (the default value is irrelevant to the local name).
1889        let info = &svelte_props(r"<script>let { a = $bindable() } = $props();</script>")[0];
1890        assert_eq!(prop_names(info), vec!["a"]);
1891    }
1892
1893    #[test]
1894    fn svelte_rest_element_sets_fallthrough_abstain() {
1895        // AC-6: `let { a, ...rest } = $props()` sets has_props_attrs_fallthrough.
1896        let info = &svelte_props(r"<script>let { a, ...rest } = $props();</script>")[0];
1897        assert!(info.has_props_attrs_fallthrough);
1898    }
1899
1900    #[test]
1901    fn svelte_bare_identifier_binding_sets_unharvestable_abstain() {
1902        // AC-7: `let p = $props()` (no destructure) sets has_unharvestable_props.
1903        let info = &svelte_props(r"<script>let p = $props(); console.log(p.x);</script>")[0];
1904        assert!(info.has_unharvestable_props);
1905        assert!(info.component_props.is_empty());
1906    }
1907
1908    #[test]
1909    fn svelte_nested_destructure_sets_unharvestable_abstain() {
1910        // A nested destructure (`{ a: { x } }`) cannot be flattened. Abstain.
1911        let info = &svelte_props(r"<script>let { a: { x } } = $props();</script>")[0];
1912        assert!(info.has_unharvestable_props);
1913    }
1914
1915    #[test]
1916    fn svelte_prop_used_only_in_markup_credited_as_template_root() {
1917        // AC-8: a prop used only in markup (`{a}`) is credited via
1918        // `apply_template_usage`, so `used_in_template` is set (parity with Vue).
1919        let info = &svelte_props(r"<script>let { a } = $props();</script><p>{a}</p>")[0];
1920        assert_eq!(prop_names(info), vec!["a"]);
1921        assert!(
1922            info.component_props[0].used_in_template,
1923            "a is used in markup, so used_in_template should be true"
1924        );
1925    }
1926
1927    #[test]
1928    fn svelte_module_script_props_not_harvested() {
1929        // `$props()` is instance-only; a module-context script must not harvest.
1930        let info = &svelte_props(
1931            r"<script module>let { a } = $props();</script><script>let { b } = $props();</script>",
1932        )[0];
1933        // Only the instance script's `b` is harvested.
1934        assert_eq!(prop_names(info), vec!["b"]);
1935    }
1936
1937    // -- Svelte custom-event dispatch harvest (unused-svelte-event) ------------
1938
1939    fn dispatched_names(info: &crate::ModuleInfo) -> Vec<String> {
1940        let mut names: Vec<String> = info
1941            .svelte_dispatched_events
1942            .iter()
1943            .map(|e| e.name.clone())
1944            .collect();
1945        names.sort();
1946        names
1947    }
1948
1949    #[test]
1950    fn svelte_dispatch_literal_event_is_harvested() {
1951        let info = &svelte_props(
1952            r"<script>import { createEventDispatcher } from 'svelte';
1953              const dispatch = createEventDispatcher();
1954              function save() { dispatch('save'); }</script>",
1955        )[0];
1956        assert_eq!(dispatched_names(info), vec!["save"]);
1957        assert!(!info.has_dynamic_dispatch);
1958    }
1959
1960    #[test]
1961    fn svelte_dispatch_without_svelte_import_is_ignored() {
1962        // A local `createEventDispatcher` not imported from `svelte` is not a
1963        // dispatcher; the `dispatch('save')` call records nothing.
1964        let info = &svelte_props(
1965            r"<script>function createEventDispatcher() { return () => {}; }
1966              const dispatch = createEventDispatcher();
1967              dispatch('save');</script>",
1968        )[0];
1969        assert!(info.svelte_dispatched_events.is_empty());
1970    }
1971
1972    #[test]
1973    fn svelte_dynamic_dispatch_sets_abstain() {
1974        let info = &svelte_props(
1975            r"<script>import { createEventDispatcher } from 'svelte';
1976              const dispatch = createEventDispatcher();
1977              function fire(name) { dispatch(name); }</script>",
1978        )[0];
1979        assert!(
1980            info.has_dynamic_dispatch,
1981            "a non-literal dispatch arg must set the abstain flag"
1982        );
1983    }
1984
1985    #[test]
1986    fn svelte_dispatch_whole_value_use_sets_abstain() {
1987        let info = &svelte_props(
1988            r"<script>import { createEventDispatcher } from 'svelte';
1989              const dispatch = createEventDispatcher();
1990              forward(dispatch);</script>",
1991        )[0];
1992        assert!(
1993            info.has_dynamic_dispatch,
1994            "passing the dispatch binding as a whole value must set the abstain flag"
1995        );
1996    }
1997
1998    #[test]
1999    fn svelte_listened_event_on_component_is_harvested() {
2000        let info =
2001            &svelte_props(r"<script>import Child from './Child.svelte';</script><Child on:save />")
2002                [0];
2003        assert!(info.svelte_listened_events.contains(&"save".to_string()));
2004    }
2005}