fallow_types/
suppress.rs

1//! Inline suppression comment types and issue kind definitions.
2
3pub use crate::issue_meta::{DEAD_CODE_FILTER_FLAGS, KNOWN_ISSUE_KIND_NAMES};
4
5/// Issue kind for suppression matching.
6///
7/// # Examples
8///
9/// ```
10/// use fallow_types::suppress::IssueKind;
11///
12/// let kind = IssueKind::parse("unused-export");
13/// assert_eq!(kind, Some(IssueKind::UnusedExport));
14///
15/// // Round-trip through discriminant
16/// let d = IssueKind::UnusedFile.to_discriminant();
17/// assert_eq!(IssueKind::from_discriminant(d), Some(IssueKind::UnusedFile));
18///
19/// // Unknown strings return None
20/// assert_eq!(IssueKind::parse("not-a-kind"), None);
21/// ```
22#[derive(Debug, Clone, Copy, PartialEq, Eq)]
23pub enum IssueKind {
24    /// An unused file.
25    UnusedFile,
26    /// An unused export.
27    UnusedExport,
28    /// An unused type export.
29    UnusedType,
30    /// An exported signature that references a same-file private type.
31    PrivateTypeLeak,
32    /// An unused dependency.
33    UnusedDependency,
34    /// An unused dev dependency.
35    UnusedDevDependency,
36    /// An unused enum member.
37    UnusedEnumMember,
38    /// An unused class member.
39    UnusedClassMember,
40    /// An unresolved import.
41    UnresolvedImport,
42    /// An unlisted dependency.
43    UnlistedDependency,
44    /// A duplicate export name across modules.
45    DuplicateExport,
46    /// Code duplication.
47    CodeDuplication,
48    /// A circular dependency chain.
49    CircularDependency,
50    /// A cycle or self-loop in the re-export edge subgraph (barrel files
51    /// re-exporting from each other in a loop). Structurally always a bug:
52    /// chain propagation through the cycle is a no-op.
53    ReExportCycle,
54    /// A production dependency only imported via type-only imports.
55    TypeOnlyDependency,
56    /// A production dependency only imported by test files.
57    TestOnlyDependency,
58    /// An import that crosses an architecture boundary.
59    BoundaryViolation,
60    /// A runtime file or export with no test dependency path.
61    CoverageGaps,
62    /// A detected feature flag pattern.
63    FeatureFlag,
64    /// A function exceeding complexity thresholds (health command).
65    Complexity,
66    /// A suppression comment or JSDoc tag that no longer matches any issue.
67    StaleSuppression,
68    /// A pnpm catalog entry in pnpm-workspace.yaml not referenced by any workspace package.
69    PnpmCatalogEntry,
70    /// A named pnpm catalog group in pnpm-workspace.yaml with no entries.
71    EmptyCatalogGroup,
72    /// A workspace package.json reference (`catalog:` / `catalog:<name>`) pointing at
73    /// a catalog that does not declare the consumed package.
74    UnresolvedCatalogReference,
75    /// An entry in pnpm's `overrides:` / `pnpm.overrides` whose target package
76    /// is not declared in any workspace `package.json`.
77    UnusedDependencyOverride,
78    /// An entry in pnpm's `overrides:` / `pnpm.overrides` whose key or value
79    /// cannot be parsed into a valid pnpm shape.
80    MisconfiguredDependencyOverride,
81    /// A `"use client"` file that transitively imports a module reading a
82    /// non-public `process.env` secret (security candidate).
83    SecurityClientServerLeak,
84    /// A syntactic tainted-sink candidate matched against the data-driven
85    /// security matcher catalogue (`security_matchers.toml`). ONE suppression
86    /// token covers all catalogue categories.
87    SecuritySink,
88    /// A banned call or banned import matched by a declarative rule pack
89    /// (`rulePacks` config). The bare token covers every pack rule; scoped
90    /// tokens can target one `<pack>/<rule-id>` identity.
91    PolicyViolation,
92    /// A `"use client"` file that exports a Next.js server-only /
93    /// route-segment config name (e.g. `metadata`, `revalidate`, `GET`).
94    InvalidClientExport,
95    /// A barrel file that re-exports BOTH a `"use client"` origin module AND a
96    /// server-only origin module (Next.js App Router footgun: one import drags
97    /// the other's directive context across the boundary).
98    MixedClientServerBarrel,
99    /// A `"use client"` / `"use server"` directive string written as an
100    /// expression statement after a non-directive statement (an import, a
101    /// const). It is no longer in the leading prologue, so the RSC bundler
102    /// parses it as an ordinary string and silently ignores it.
103    MisplacedDirective,
104    /// A store member (Pinia `state` / `getters` / `actions` key, or a
105    /// setup-store returned key) declared but never accessed by any consumer
106    /// project-wide. Cross-graph: the store binding is imported (the module is
107    /// reachable) yet a specific member is dead.
108    UnusedStoreMember,
109    /// A Vue `inject(KEY)` or Svelte `getContext(KEY)` whose symbol KEY is
110    /// `provide`/`setContext`'d nowhere in the analyzed project. Cross-graph
111    /// dead-half DI link: at runtime the inject returns `undefined`.
112    UnprovidedInject,
113    /// Two or more Next.js App Router route files that resolve to the same URL
114    /// within one app-root (a guaranteed `next build` failure).
115    RouteCollision,
116    /// Sibling Next.js dynamic route segments at one tree position using
117    /// different param spellings (`[id]` vs `[slug]`; a dev / runtime error
118    /// that `next build` does NOT catch).
119    DynamicSegmentNameConflict,
120    /// A component defined in the project that is exported but never rendered
121    /// (no JSX usage) anywhere across the analyzed project.
122    UnrenderedComponent,
123    /// A Vue `<script setup>` `defineProps`, Svelte 5 `$props()`, or React
124    /// declared prop that is referenced NOWHERE inside its own component.
125    /// Single-component dead-input direction.
126    UnusedComponentProp,
127    /// A Vue `<script setup>` `defineEmits` declared event that is EMITTED
128    /// nowhere inside its own single-file component (no `emit('<name>')` call).
129    /// Single-file dead-input direction.
130    UnusedComponentEmit,
131    /// An Angular `@Input()` / signal `input()` / `model()` declared input that
132    /// is read NOWHERE inside its own component (neither the inline/external
133    /// template nor the class body). Single-file dead-input direction; the
134    /// Angular analogue of `unused-component-prop`.
135    UnusedComponentInput,
136    /// An Angular `@Output()` / signal `output()` declared output that is
137    /// EMITTED nowhere inside its own component (no `this.<output>.emit(...)`).
138    /// Single-file dead-output direction; the Angular analogue of
139    /// `unused-component-emit`.
140    UnusedComponentOutput,
141    /// A Next.js Server Action (an export of a `"use server"` file) that no code
142    /// in the project references (no import-and-call, no `action={fn}` binding,
143    /// no `<form action={fn}>`). Cross-graph dead-export direction, reclassified
144    /// from `unused-export` for `"use server"` files.
145    UnusedServerAction,
146    /// A SvelteKit `+page.{ts,server.ts,js,server.js}` `load()` return-object key
147    /// that no consumer reads: not off the sibling `+page.svelte`'s `data.<key>`,
148    /// nor project-wide via `page.data.<key>` / `$page.data.<key>`. A dead load
149    /// key runs a real server/DB fetch cost for data nothing renders.
150    UnusedLoadDataKey,
151    /// A React/Preact prop forwarded unchanged through `>= N` intermediate
152    /// pass-through components until a component that substantively consumes it.
153    /// Health signal, rule defaults to `off` (opt-in). Cross-graph: the chain
154    /// spans multiple components / files.
155    PropDrilling,
156    /// A React/Preact component whose entire body is `return <Child {...props}/>`
157    /// (a single spread-forwarded child render, no own value-add): pure
158    /// structural indirection, a candidate for inlining. Health signal, rule
159    /// defaults to `off` (opt-in).
160    ThinWrapper,
161    /// Three or more React/Preact components across two or more files whose
162    /// statically-harvested prop NAME set is identical after stripping ubiquitous
163    /// DOM / passthrough names (a missing shared `Props` type). Health signal,
164    /// rule defaults to `off` (opt-in). Cross-graph: the group spans multiple
165    /// components / files.
166    DuplicatePropShape,
167    /// A Svelte component dispatching a custom event via
168    /// `createEventDispatcher()` whose event name is listened to NOWHERE in the
169    /// analyzed project. Cross-file dead-output direction: the component fires an
170    /// event nothing handles.
171    UnusedSvelteEvent,
172    /// A CSS / CSS-in-JS design-token DRIFT candidate surfaced in `fallow audit`
173    /// as an advisory styling finding: a hardcoded value where a design token
174    /// exists (a Tailwind arbitrary value like `w-[13px]`, or a near-duplicate
175    /// token). Styling-domain finding produced by the health-time css pass (not
176    /// dead-code); the rule defaults to `warn` and is verdict-neutral.
177    CssTokenDrift,
178    /// A CSS / CSS-in-JS DUPLICATE declaration block: a copy-pasted rule body
179    /// repeated across selectors, a consolidation candidate. Styling-domain
180    /// advisory (rule defaults to `warn`, verdict-neutral); the audit copy of
181    /// this is changed-file-local.
182    CssDuplicateBlock,
183    /// A CSS selector / nesting / important-density complexity finding surfaced
184    /// as advisory styling feedback. Styling-domain finding produced by the
185    /// health-time css pass; defaults to `warn` and is verdict-neutral.
186    CssSelectorComplexity,
187    /// A CSS dead-surface finding, such as unused scoped SFC classes. Styling-
188    /// domain advisory surfaced in `fallow audit`; defaults to `warn` and is
189    /// verdict-neutral.
190    CssDeadSurface,
191    /// A CSS broken-reference finding, such as a class or keyframes reference
192    /// that resolves to no stylesheet definition. Styling-domain advisory
193    /// surfaced by deep CSS audit mode; defaults to `warn` and is
194    /// verdict-neutral.
195    CssBrokenReference,
196    /// A `devDependencies` package imported by production (non-test, non-config)
197    /// source code via a runtime/value import. It should be promoted to
198    /// `dependencies` because a production-only install (`pnpm install --prod`)
199    /// would omit it and break at runtime. The promote-side mirror of
200    /// `test-only-dependency` / `type-only-dependency`.
201    DevDependencyInProduction,
202}
203
204impl IssueKind {
205    /// Stable inventory of all issue kinds.
206    pub const ALL: &'static [Self] = &[
207        Self::UnusedFile,
208        Self::UnusedExport,
209        Self::UnusedType,
210        Self::PrivateTypeLeak,
211        Self::UnusedDependency,
212        Self::UnusedDevDependency,
213        Self::UnusedEnumMember,
214        Self::UnusedClassMember,
215        Self::UnresolvedImport,
216        Self::UnlistedDependency,
217        Self::DuplicateExport,
218        Self::CodeDuplication,
219        Self::CircularDependency,
220        Self::ReExportCycle,
221        Self::TypeOnlyDependency,
222        Self::TestOnlyDependency,
223        Self::BoundaryViolation,
224        Self::CoverageGaps,
225        Self::FeatureFlag,
226        Self::Complexity,
227        Self::StaleSuppression,
228        Self::PnpmCatalogEntry,
229        Self::EmptyCatalogGroup,
230        Self::UnresolvedCatalogReference,
231        Self::UnusedDependencyOverride,
232        Self::MisconfiguredDependencyOverride,
233        Self::SecurityClientServerLeak,
234        Self::SecuritySink,
235        Self::PolicyViolation,
236        Self::InvalidClientExport,
237        Self::MixedClientServerBarrel,
238        Self::MisplacedDirective,
239        Self::UnusedStoreMember,
240        Self::UnprovidedInject,
241        Self::RouteCollision,
242        Self::DynamicSegmentNameConflict,
243        Self::UnrenderedComponent,
244        Self::UnusedComponentProp,
245        Self::UnusedComponentEmit,
246        Self::UnusedComponentInput,
247        Self::UnusedComponentOutput,
248        Self::UnusedServerAction,
249        Self::UnusedLoadDataKey,
250        Self::PropDrilling,
251        Self::ThinWrapper,
252        Self::DuplicatePropShape,
253        Self::UnusedSvelteEvent,
254        Self::CssTokenDrift,
255        Self::CssDuplicateBlock,
256        Self::CssSelectorComplexity,
257        Self::CssDeadSurface,
258        Self::CssBrokenReference,
259        Self::DevDependencyInProduction,
260    ];
261
262    /// Parse an issue kind from the string tokens used in CLI output and suppression comments.
263    #[must_use]
264    pub fn parse(s: &str) -> Option<Self> {
265        crate::issue_meta::issue_meta_for_token(s).and_then(|meta| meta.kind)
266    }
267
268    /// Convert to a u8 discriminant for compact cache storage.
269    #[must_use]
270    pub const fn to_discriminant(self) -> u8 {
271        match self {
272            Self::UnusedFile => 1,
273            Self::UnusedExport => 2,
274            Self::UnusedType => 3,
275            Self::PrivateTypeLeak => 4,
276            Self::UnusedDependency => 5,
277            Self::UnusedDevDependency => 6,
278            Self::UnusedEnumMember => 7,
279            Self::UnusedClassMember => 8,
280            Self::UnresolvedImport => 9,
281            Self::UnlistedDependency => 10,
282            Self::DuplicateExport => 11,
283            Self::CodeDuplication => 12,
284            Self::CircularDependency => 13,
285            Self::TypeOnlyDependency => 14,
286            Self::TestOnlyDependency => 15,
287            Self::BoundaryViolation => 16,
288            Self::CoverageGaps => 17,
289            Self::FeatureFlag => 18,
290            Self::Complexity => 19,
291            Self::StaleSuppression => 20,
292            Self::PnpmCatalogEntry => 21,
293            Self::UnresolvedCatalogReference => 22,
294            Self::UnusedDependencyOverride => 23,
295            Self::MisconfiguredDependencyOverride => 24,
296            Self::EmptyCatalogGroup => 25,
297            Self::ReExportCycle => 26,
298            Self::SecurityClientServerLeak => 27,
299            Self::SecuritySink => 28,
300            Self::PolicyViolation => 29,
301            Self::InvalidClientExport => 30,
302            Self::MixedClientServerBarrel => 31,
303            Self::MisplacedDirective => 32,
304            Self::UnusedStoreMember => 33,
305            Self::UnprovidedInject => 34,
306            Self::RouteCollision => 35,
307            Self::DynamicSegmentNameConflict => 36,
308            Self::UnrenderedComponent => 37,
309            Self::UnusedComponentProp => 38,
310            Self::UnusedComponentEmit => 39,
311            Self::UnusedServerAction => 40,
312            Self::UnusedLoadDataKey => 41,
313            Self::PropDrilling => 42,
314            Self::ThinWrapper => 43,
315            Self::DuplicatePropShape => 44,
316            Self::UnusedComponentInput => 45,
317            Self::UnusedComponentOutput => 46,
318            Self::UnusedSvelteEvent => 47,
319            Self::CssTokenDrift => 48,
320            Self::CssDuplicateBlock => 49,
321            Self::CssSelectorComplexity => 50,
322            Self::CssDeadSurface => 51,
323            Self::CssBrokenReference => 52,
324            Self::DevDependencyInProduction => 53,
325        }
326    }
327
328    /// Reconstruct from a cache discriminant.
329    #[must_use]
330    pub const fn from_discriminant(d: u8) -> Option<Self> {
331        match d {
332            1 => Some(Self::UnusedFile),
333            2 => Some(Self::UnusedExport),
334            3 => Some(Self::UnusedType),
335            4 => Some(Self::PrivateTypeLeak),
336            5 => Some(Self::UnusedDependency),
337            6 => Some(Self::UnusedDevDependency),
338            7 => Some(Self::UnusedEnumMember),
339            8 => Some(Self::UnusedClassMember),
340            9 => Some(Self::UnresolvedImport),
341            10 => Some(Self::UnlistedDependency),
342            11 => Some(Self::DuplicateExport),
343            12 => Some(Self::CodeDuplication),
344            13 => Some(Self::CircularDependency),
345            14 => Some(Self::TypeOnlyDependency),
346            15 => Some(Self::TestOnlyDependency),
347            16 => Some(Self::BoundaryViolation),
348            17 => Some(Self::CoverageGaps),
349            18 => Some(Self::FeatureFlag),
350            19 => Some(Self::Complexity),
351            20 => Some(Self::StaleSuppression),
352            21 => Some(Self::PnpmCatalogEntry),
353            22 => Some(Self::UnresolvedCatalogReference),
354            23 => Some(Self::UnusedDependencyOverride),
355            24 => Some(Self::MisconfiguredDependencyOverride),
356            25 => Some(Self::EmptyCatalogGroup),
357            26 => Some(Self::ReExportCycle),
358            27 => Some(Self::SecurityClientServerLeak),
359            28 => Some(Self::SecuritySink),
360            29 => Some(Self::PolicyViolation),
361            30 => Some(Self::InvalidClientExport),
362            31 => Some(Self::MixedClientServerBarrel),
363            32 => Some(Self::MisplacedDirective),
364            33 => Some(Self::UnusedStoreMember),
365            34 => Some(Self::UnprovidedInject),
366            35 => Some(Self::RouteCollision),
367            36 => Some(Self::DynamicSegmentNameConflict),
368            37 => Some(Self::UnrenderedComponent),
369            38 => Some(Self::UnusedComponentProp),
370            39 => Some(Self::UnusedComponentEmit),
371            40 => Some(Self::UnusedServerAction),
372            41 => Some(Self::UnusedLoadDataKey),
373            42 => Some(Self::PropDrilling),
374            43 => Some(Self::ThinWrapper),
375            44 => Some(Self::DuplicatePropShape),
376            45 => Some(Self::UnusedComponentInput),
377            46 => Some(Self::UnusedComponentOutput),
378            47 => Some(Self::UnusedSvelteEvent),
379            48 => Some(Self::CssTokenDrift),
380            49 => Some(Self::CssDuplicateBlock),
381            50 => Some(Self::CssSelectorComplexity),
382            51 => Some(Self::CssDeadSurface),
383            52 => Some(Self::CssBrokenReference),
384            53 => Some(Self::DevDependencyInProduction),
385            _ => None,
386        }
387    }
388}
389
390/// One scoped rule-pack policy suppression target.
391#[derive(Debug, Clone, PartialEq, Eq, Hash)]
392pub struct PolicyRuleSuppression {
393    /// Rule-pack name.
394    pub pack: String,
395    /// Rule id within the pack.
396    pub rule_id: String,
397}
398
399impl PolicyRuleSuppression {
400    /// Build a scoped policy suppression target.
401    #[must_use]
402    pub fn new(pack: impl Into<String>, rule_id: impl Into<String>) -> Self {
403        Self {
404            pack: pack.into(),
405            rule_id: rule_id.into(),
406        }
407    }
408
409    /// Canonical suppression token.
410    #[must_use]
411    pub fn token(&self) -> String {
412        format!("policy-violation:{}/{}", self.pack, self.rule_id)
413    }
414}
415
416/// A specific suppression target parsed from a comment token.
417#[derive(Debug, Clone, PartialEq, Eq)]
418pub enum SuppressionTarget {
419    /// A regular issue-kind token such as `unused-export` or bare
420    /// `policy-violation`.
421    Issue(IssueKind),
422    /// A scoped rule-pack policy token such as
423    /// `policy-violation:team-policy/no-child-process`.
424    PolicyRule(PolicyRuleSuppression),
425}
426
427impl SuppressionTarget {
428    /// Return the regular issue kind when this target is a bare issue-kind
429    /// token.
430    #[must_use]
431    pub const fn issue_kind(&self) -> Option<IssueKind> {
432        match self {
433            Self::Issue(kind) => Some(*kind),
434            Self::PolicyRule(_) => None,
435        }
436    }
437
438    /// Canonical suppression token for output and active-suppression capture.
439    #[must_use]
440    pub fn token(&self) -> String {
441        match self {
442            Self::Issue(kind) => issue_kind_to_kebab(*kind).to_owned(),
443            Self::PolicyRule(rule) => rule.token(),
444        }
445    }
446}
447
448/// Convert an [`IssueKind`] to its canonical suppression token.
449#[must_use]
450pub fn issue_kind_to_kebab(kind: IssueKind) -> &'static str {
451    let Some(meta) = crate::issue_meta::issue_meta_by_kind(kind) else {
452        unreachable!("IssueKind {kind:?} has no metadata row");
453    };
454    meta.suppress_token.unwrap_or(meta.code)
455}
456
457/// Parse a suppression token into a structured target.
458#[must_use]
459pub fn parse_suppression_target(token: &str) -> Option<SuppressionTarget> {
460    parse_policy_rule_suppression_token(token)
461        .map(SuppressionTarget::PolicyRule)
462        .or_else(|| IssueKind::parse(token).map(SuppressionTarget::Issue))
463}
464
465/// Parse canonical scoped policy suppression tokens.
466///
467/// The plural prefix is accepted for consistency with the bare legacy alias,
468/// but output always uses singular `policy-violation:`.
469#[must_use]
470pub fn parse_policy_rule_suppression_token(token: &str) -> Option<PolicyRuleSuppression> {
471    let identity = token
472        .strip_prefix("policy-violation:")
473        .or_else(|| token.strip_prefix("policy-violations:"))?;
474    let (pack, rule_id) = identity.split_once('/')?;
475    if rule_id.contains('/') {
476        return None;
477    }
478    if !is_valid_policy_identifier(pack) || !is_valid_policy_identifier(rule_id) {
479        return None;
480    }
481    Some(PolicyRuleSuppression::new(pack, rule_id))
482}
483
484/// Whether a rule-pack name or rule id can be used inside
485/// `policy-violation:<pack>/<rule-id>` without escaping.
486#[must_use]
487pub fn is_valid_policy_identifier(value: &str) -> bool {
488    !value.is_empty()
489        && value
490            .bytes()
491            .all(|b| b.is_ascii_alphanumeric() || matches!(b, b'.' | b'_' | b'-'))
492}
493
494/// A suppression directive parsed from a source comment.
495///
496/// # Examples
497///
498/// ```
499/// use fallow_types::suppress::{Suppression, IssueKind};
500///
501/// // File-wide suppression (line 0, no specific kind)
502/// let file_wide = Suppression::all(0, 1);
503/// assert_eq!(file_wide.line, 0);
504///
505/// // Line-specific suppression for unused exports
506/// let line_suppress = Suppression::issue(42, 41, IssueKind::UnusedExport);
507/// assert_eq!(line_suppress.issue_kind_target(), Some(IssueKind::UnusedExport));
508/// ```
509#[derive(Debug, Clone)]
510pub struct Suppression {
511    /// 1-based line this suppression applies to. 0 = file-wide suppression.
512    pub line: u32,
513    /// 1-based line where the suppression comment itself appears.
514    /// For `fallow-ignore-next-line`, this is `line - 1`.
515    /// For `fallow-ignore-file`, this is the actual line of the comment in the source.
516    pub comment_line: u32,
517    /// None = suppress all issue kinds on this line or file.
518    pub target: Option<SuppressionTarget>,
519    /// Human-authored reason after `--`, when present.
520    pub reason: Option<String>,
521}
522
523impl Suppression {
524    /// Build a blanket suppression.
525    #[must_use]
526    pub const fn all(line: u32, comment_line: u32) -> Self {
527        Self {
528            line,
529            comment_line,
530            target: None,
531            reason: None,
532        }
533    }
534
535    /// Build a regular issue-kind suppression.
536    #[must_use]
537    pub const fn issue(line: u32, comment_line: u32, kind: IssueKind) -> Self {
538        Self {
539            line,
540            comment_line,
541            target: Some(SuppressionTarget::Issue(kind)),
542            reason: None,
543        }
544    }
545
546    /// Build a scoped rule-pack policy suppression.
547    #[must_use]
548    pub fn policy_rule(
549        line: u32,
550        comment_line: u32,
551        pack: impl Into<String>,
552        rule_id: impl Into<String>,
553    ) -> Self {
554        Self {
555            line,
556            comment_line,
557            target: Some(SuppressionTarget::PolicyRule(PolicyRuleSuppression::new(
558                pack, rule_id,
559            ))),
560            reason: None,
561        }
562    }
563
564    /// Return a copy with a parsed suppression reason attached.
565    #[must_use]
566    pub fn with_reason(mut self, reason: Option<String>) -> Self {
567        self.reason = reason;
568        self
569    }
570
571    /// The bare issue kind if this suppression targets one.
572    #[must_use]
573    pub const fn issue_kind_target(&self) -> Option<IssueKind> {
574        match &self.target {
575            Some(SuppressionTarget::Issue(kind)) => Some(*kind),
576            Some(SuppressionTarget::PolicyRule(_)) | None => None,
577        }
578    }
579
580    /// The scoped policy target if this suppression targets one rule-pack rule.
581    #[must_use]
582    pub const fn policy_rule_target(&self) -> Option<&PolicyRuleSuppression> {
583        match &self.target {
584            Some(SuppressionTarget::PolicyRule(rule)) => Some(rule),
585            Some(SuppressionTarget::Issue(_)) | None => None,
586        }
587    }
588
589    /// Canonical token for this suppression, or `None` for blanket comments.
590    #[must_use]
591    pub fn target_token(&self) -> Option<String> {
592        self.target.as_ref().map(SuppressionTarget::token)
593    }
594
595    /// Whether the comment applies to `line`.
596    #[must_use]
597    pub const fn applies_to_line(&self, line: u32) -> bool {
598        self.line == 0 || self.line == line
599    }
600
601    /// Whether this suppression covers a regular issue kind on a line.
602    ///
603    /// Scoped policy-rule targets intentionally do not match this generic
604    /// predicate. Policy detection uses [`Self::matches_policy_rule`] so the
605    /// exact pack and rule id are available.
606    #[must_use]
607    pub fn matches_issue_kind(&self, line: u32, kind: IssueKind) -> bool {
608        self.applies_to_line(line)
609            && match &self.target {
610                None => true,
611                Some(SuppressionTarget::Issue(target_kind)) => *target_kind == kind,
612                Some(SuppressionTarget::PolicyRule(_)) => false,
613            }
614    }
615
616    /// Whether this suppression covers a policy finding on a line.
617    #[must_use]
618    pub fn matches_policy_rule(&self, line: u32, pack: &str, rule_id: &str) -> bool {
619        self.applies_to_line(line)
620            && match &self.target {
621                None | Some(SuppressionTarget::Issue(IssueKind::PolicyViolation)) => true,
622                Some(SuppressionTarget::Issue(_)) => false,
623                Some(SuppressionTarget::PolicyRule(target)) => {
624                    target.pack == pack && target.rule_id == rule_id
625                }
626            }
627    }
628}
629
630/// Check if a specific issue at a given line should be suppressed.
631#[must_use]
632pub fn is_suppressed(suppressions: &[Suppression], line: u32, kind: IssueKind) -> bool {
633    suppressions
634        .iter()
635        .any(|suppression| suppression.matches_issue_kind(line, kind))
636}
637
638/// Check if the entire file is suppressed for issue types that do not have line numbers.
639#[must_use]
640pub fn is_file_suppressed(suppressions: &[Suppression], kind: IssueKind) -> bool {
641    suppressions
642        .iter()
643        .any(|suppression| suppression.line == 0 && suppression.matches_issue_kind(0, kind))
644}
645
646/// A suppression token that did not parse to any known `IssueKind`.
647///
648/// Emitted alongside `Suppression` when a `// fallow-ignore-*` marker contains
649/// a typo or an obsolete issue-kind name. The known tokens on the same marker
650/// are recorded as normal `Suppression` entries; this struct preserves the
651/// unknown token so the downstream `find_stale` pass can surface it as a
652/// `StaleSuppression` finding with `kind_known: false`. Without this, the
653/// entire suppression line would be discarded silently. See issue #449.
654#[derive(Debug, Clone)]
655pub struct UnknownSuppressionKind {
656    /// 1-based line where the suppression comment itself appears.
657    pub comment_line: u32,
658    /// Whether the marker was `fallow-ignore-file` (`true`) or
659    /// `fallow-ignore-next-line` (`false`).
660    pub is_file_level: bool,
661    /// The verbatim token from the marker that did not parse.
662    pub token: String,
663    /// Human-authored reason after `--`, when present.
664    pub reason: Option<String>,
665}
666
667/// Levenshtein edit distance between two ASCII-leaning strings.
668///
669/// Local duplicate of the config-crate helper (see
670/// `crates/config/src/config/rules.rs::levenshtein`) so `fallow-types` can
671/// compute "did you mean?" suggestions for unknown suppression tokens without
672/// taking a dependency on `fallow-config`. Issue-kind names are short
673/// (max ~33 chars) so allocation cost is negligible.
674fn levenshtein(a: &str, b: &str) -> usize {
675    let a_bytes = a.as_bytes();
676    let b_bytes = b.as_bytes();
677    let (a_len, b_len) = (a_bytes.len(), b_bytes.len());
678
679    if a_len == 0 {
680        return b_len;
681    }
682    if b_len == 0 {
683        return a_len;
684    }
685
686    let mut prev: Vec<usize> = (0..=b_len).collect();
687    let mut curr: Vec<usize> = vec![0; b_len + 1];
688
689    for i in 1..=a_len {
690        curr[0] = i;
691        for j in 1..=b_len {
692            let cost = usize::from(a_bytes[i - 1] != b_bytes[j - 1]);
693            curr[j] = (prev[j] + 1).min(curr[j - 1] + 1).min(prev[j - 1] + cost);
694        }
695        std::mem::swap(&mut prev, &mut curr);
696    }
697
698    prev[b_len]
699}
700
701/// Find the closest known issue-kind name to `input` when it is plausibly a typo.
702///
703/// Returns the best match when the Levenshtein distance is at most 2 AND
704/// the input is long enough that the match is not coincidental
705/// (`input.len() / 2 > distance`). Returns `None` for completely novel
706/// strings where a suggestion would be misleading.
707#[must_use]
708pub fn closest_known_kind_name(input: &str) -> Option<&'static str> {
709    let input_lower = input.to_ascii_lowercase();
710    let mut best: Option<(&'static str, usize)> = None;
711
712    for &candidate in KNOWN_ISSUE_KIND_NAMES.iter() {
713        let d = levenshtein(&input_lower, candidate);
714        if best.is_none_or(|(_, b_dist)| d < b_dist) {
715            best = Some((candidate, d));
716        }
717    }
718
719    best.filter(|&(_, d)| d > 0 && d <= 2 && input_lower.len() / 2 > d)
720        .map(|(name, _)| name)
721}
722
723const _: () = assert!(std::mem::size_of::<IssueKind>() == 1);
724
725#[cfg(test)]
726mod tests {
727    use super::*;
728
729    #[test]
730    fn issue_kind_parse_accepts_registry_codes_and_aliases() {
731        for meta in crate::issue_meta::ISSUE_KIND_META
732            .iter()
733            .filter(|meta| meta.kind.is_some())
734        {
735            let expected = meta.kind;
736            assert_eq!(
737                IssueKind::parse(meta.code),
738                expected,
739                "canonical registry token {} must parse",
740                meta.code
741            );
742            for alias in meta.aliases {
743                assert_eq!(
744                    IssueKind::parse(alias),
745                    expected,
746                    "registry alias {alias} must parse as {}",
747                    meta.code
748                );
749            }
750        }
751    }
752
753    #[test]
754    fn issue_kind_parse_accepts_registry_suppression_tokens() {
755        for meta in crate::issue_meta::ISSUE_KIND_META {
756            let (Some(kind), Some(token)) = (meta.kind, meta.suppress_token) else {
757                continue;
758            };
759            assert_eq!(
760                IssueKind::parse(token),
761                Some(kind),
762                "registry suppression token {token} must parse as {}",
763                meta.code
764            );
765        }
766    }
767
768    #[test]
769    fn issue_kind_from_str_unknown() {
770        assert_eq!(IssueKind::parse("foo"), None);
771        assert_eq!(IssueKind::parse(""), None);
772    }
773
774    #[test]
775    fn issue_kind_from_str_near_misses() {
776        assert_eq!(IssueKind::parse("Unused-File"), None);
777        assert_eq!(IssueKind::parse("UNUSED-EXPORT"), None);
778        assert_eq!(IssueKind::parse("unused_file"), None);
779        assert_eq!(IssueKind::parse("unused-files"), None);
780    }
781
782    #[test]
783    fn discriminant_out_of_range() {
784        // Pin exact discriminants so an inserted or reordered variant that
785        // shifts wire values is caught. `ALL` is not discriminant-ordered, so
786        // the mapping is spelled out explicitly.
787        let cases: &[(u8, IssueKind)] = &[
788            (29, IssueKind::PolicyViolation),
789            (30, IssueKind::InvalidClientExport),
790            (31, IssueKind::MixedClientServerBarrel),
791            (32, IssueKind::MisplacedDirective),
792            (33, IssueKind::UnusedStoreMember),
793            (34, IssueKind::UnprovidedInject),
794            (35, IssueKind::RouteCollision),
795            (36, IssueKind::DynamicSegmentNameConflict),
796            (37, IssueKind::UnrenderedComponent),
797            (38, IssueKind::UnusedComponentProp),
798            (39, IssueKind::UnusedComponentEmit),
799            (40, IssueKind::UnusedServerAction),
800            (41, IssueKind::UnusedLoadDataKey),
801            (42, IssueKind::PropDrilling),
802            (43, IssueKind::ThinWrapper),
803            (44, IssueKind::DuplicatePropShape),
804            (45, IssueKind::UnusedComponentInput),
805            (46, IssueKind::UnusedComponentOutput),
806            (47, IssueKind::UnusedSvelteEvent),
807            (48, IssueKind::CssTokenDrift),
808            (49, IssueKind::CssDuplicateBlock),
809            (50, IssueKind::CssSelectorComplexity),
810            (51, IssueKind::CssDeadSurface),
811            (52, IssueKind::CssBrokenReference),
812            (53, IssueKind::DevDependencyInProduction),
813        ];
814        for &(discriminant, kind) in cases {
815            assert_eq!(kind.to_discriminant(), discriminant, "{kind:?} drifted");
816            assert_eq!(IssueKind::from_discriminant(discriminant), Some(kind));
817        }
818        assert_eq!(IssueKind::from_discriminant(0), None);
819        let max_discriminant = IssueKind::ALL
820            .iter()
821            .map(|kind| kind.to_discriminant())
822            .max()
823            .expect("IssueKind::ALL should not be empty");
824        assert_eq!(IssueKind::from_discriminant(max_discriminant + 1), None);
825        assert_eq!(IssueKind::from_discriminant(u8::MAX), None);
826    }
827
828    #[test]
829    fn discriminant_roundtrip() {
830        for &kind in IssueKind::ALL {
831            assert_eq!(
832                IssueKind::from_discriminant(kind.to_discriminant()),
833                Some(kind)
834            );
835        }
836        assert_eq!(IssueKind::from_discriminant(0), None);
837        let max_discriminant = IssueKind::ALL
838            .iter()
839            .map(|kind| kind.to_discriminant())
840            .max()
841            .expect("IssueKind::ALL should not be empty");
842        assert_eq!(IssueKind::from_discriminant(max_discriminant + 1), None);
843    }
844
845    #[test]
846    fn discriminant_values_are_unique() {
847        let discriminants: Vec<u8> = IssueKind::ALL
848            .iter()
849            .map(|kind| kind.to_discriminant())
850            .collect();
851        let mut sorted = discriminants.clone();
852        sorted.sort_unstable();
853        sorted.dedup();
854        assert_eq!(
855            discriminants.len(),
856            sorted.len(),
857            "discriminant values must be unique"
858        );
859    }
860
861    #[test]
862    fn discriminant_starts_at_one() {
863        assert_eq!(IssueKind::UnusedFile.to_discriminant(), 1);
864    }
865
866    #[test]
867    fn issue_kind_to_kebab_uses_registry_suppression_token() {
868        for &kind in IssueKind::ALL {
869            let meta = crate::issue_meta::issue_meta_by_kind(kind)
870                .unwrap_or_else(|| panic!("IssueKind {kind:?} has no metadata row"));
871            let token = issue_kind_to_kebab(kind);
872            assert_eq!(token, meta.suppress_token.unwrap_or(meta.code));
873            assert_eq!(IssueKind::parse(token), Some(kind));
874        }
875    }
876
877    #[test]
878    fn suppression_line_zero_is_file_wide() {
879        let s = Suppression::all(0, 1);
880        assert_eq!(s.line, 0);
881        assert!(s.issue_kind_target().is_none());
882    }
883
884    #[test]
885    fn suppression_with_specific_kind_and_line() {
886        let s = Suppression::issue(42, 41, IssueKind::UnusedExport);
887        assert_eq!(s.line, 42);
888        assert_eq!(s.comment_line, 41);
889        assert_eq!(s.issue_kind_target(), Some(IssueKind::UnusedExport));
890    }
891
892    #[test]
893    fn suppression_predicates_match_lines_and_file_wide_markers() {
894        let suppressions = vec![
895            Suppression::issue(42, 41, IssueKind::UnusedExport),
896            Suppression::all(0, 1),
897        ];
898
899        assert!(is_suppressed(&suppressions, 42, IssueKind::UnusedExport));
900        assert!(is_suppressed(&suppressions, 10, IssueKind::UnusedType));
901        assert!(is_file_suppressed(&suppressions, IssueKind::UnusedFile));
902    }
903
904    #[test]
905    fn parses_scoped_policy_suppression_token() {
906        let target =
907            parse_policy_rule_suppression_token("policy-violation:team-policy/no-child-process")
908                .expect("scoped token should parse");
909        assert_eq!(target.pack, "team-policy");
910        assert_eq!(target.rule_id, "no-child-process");
911        assert_eq!(
912            target.token(),
913            "policy-violation:team-policy/no-child-process"
914        );
915    }
916
917    #[test]
918    fn rejects_malformed_scoped_policy_suppression_tokens() {
919        for token in [
920            "policy-violation:",
921            "policy-violation:team-policy",
922            "policy-violation:/no-child-process",
923            "policy-violation:team-policy/",
924            "policy-violation:team-policy/no/child-process",
925            "policy-violation:team policy/no-child-process",
926            "policy-violation:team-policy/no:child-process",
927        ] {
928            assert!(
929                parse_policy_rule_suppression_token(token).is_none(),
930                "{token} should be rejected"
931            );
932        }
933    }
934
935    #[test]
936    fn scoped_policy_suppression_matches_exact_policy_rule_only() {
937        let suppression = Suppression::policy_rule(7, 6, "team-policy", "no-child-process");
938        assert!(suppression.matches_policy_rule(7, "team-policy", "no-child-process"));
939        assert!(!suppression.matches_policy_rule(7, "team-policy", "no-fs"));
940        assert!(!suppression.matches_policy_rule(8, "team-policy", "no-child-process"));
941        assert!(!suppression.matches_issue_kind(7, IssueKind::PolicyViolation));
942    }
943
944    #[test]
945    fn known_issue_kind_names_parses_each_entry() {
946        for &name in KNOWN_ISSUE_KIND_NAMES.iter() {
947            assert!(
948                IssueKind::parse(name).is_some(),
949                "KNOWN_ISSUE_KIND_NAMES contains '{name}' but IssueKind::parse rejects it"
950            );
951        }
952    }
953
954    #[test]
955    fn closest_known_kind_name_finds_near_misses() {
956        assert_eq!(
957            closest_known_kind_name("unused-exports"),
958            Some("unused-export")
959        );
960        assert_eq!(closest_known_kind_name("unused-files"), Some("unused-file"));
961        assert_eq!(closest_known_kind_name("complxity"), Some("complexity"));
962    }
963
964    #[test]
965    fn closest_known_kind_name_rejects_novel_strings() {
966        assert_eq!(closest_known_kind_name("xyzzy"), None);
967        assert_eq!(closest_known_kind_name("foo"), None);
968        assert_eq!(closest_known_kind_name(""), None);
969    }
970
971    #[test]
972    fn closest_known_kind_name_skips_exact_match() {
973        assert_eq!(closest_known_kind_name("unused-export"), None);
974    }
975}
fallow_types/suppress.rs

fallow_types/
suppress.rs
