rumdl_lib/rules/
md053_link_image_reference_definitions.rs

1use crate::rule::{LintError, LintResult, LintWarning, Rule, Severity};
2use crate::rule_config_serde::RuleConfig;
3use crate::utils::document_structure::DocumentStructure;
4use crate::utils::range_utils::calculate_line_range;
5use fancy_regex::Regex as FancyRegex;
6use lazy_static::lazy_static;
7use regex::Regex;
8use serde::{Deserialize, Serialize};
9use std::collections::{HashMap, HashSet};
10
11lazy_static! {
12    // Link reference format: [text][reference]
13    // REMOVED: static ref LINK_REFERENCE_REGEX: FancyRegex = FancyRegex::new(r"\[([^\]]*)\]\s*\[([^\]]*)\]").unwrap();
14
15    // Image reference format: ![text][reference]
16    // REMOVED: static ref IMAGE_REFERENCE_REGEX: FancyRegex = FancyRegex::new(r"!\[([^\]]*)\]\s*\[([^\]]*)\]").unwrap();
17
18    // Shortcut reference links: [reference] - must not be followed by another bracket
19    // Allow references followed by punctuation like colon, period, comma (e.g., "[reference]:", "[reference].")
20    // Don't exclude references followed by ": " in the middle of a line (only at start of line)
21    static ref SHORTCUT_REFERENCE_REGEX: FancyRegex =
22        FancyRegex::new(r"(?<!\!)\[([^\]]+)\](?!\[)").unwrap();
23
24    // REMOVED: Empty reference links: [text][] or ![text][]
25    // static ref EMPTY_LINK_REFERENCE_REGEX: Regex = Regex::new(r"\[([^\]]+)\]\s*\[\s*\]").unwrap();
26    // static ref EMPTY_IMAGE_REFERENCE_REGEX: Regex = Regex::new(r"!\[([^\]]+)\]\s*\[\s*\]").unwrap();
27
28    // Link/image reference definition format: [reference]: URL
29    static ref REFERENCE_DEFINITION_REGEX: Regex =
30        Regex::new(r"^\s*\[([^\]]+)\]:\s+(.+)$").unwrap();
31
32    // Multi-line reference definition continuation pattern
33    static ref CONTINUATION_REGEX: Regex = Regex::new(r"^\s+(.+)$").unwrap();
34
35    // Code block regex - support indented code blocks for MkDocs tabs
36    static ref CODE_BLOCK_START_REGEX: Regex = Regex::new(r"^(\s*)(`{3,}|~{3,})").unwrap();
37    static ref CODE_BLOCK_END_REGEX: Regex = Regex::new(r"^(\s*)(`{3,}|~{3,})\s*$").unwrap();
38}
39
40/// Configuration for MD053 rule
41#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
42#[serde(rename_all = "kebab-case")]
43pub struct MD053Config {
44    /// List of reference names to keep even if unused
45    #[serde(default = "default_ignored_definitions")]
46    pub ignored_definitions: Vec<String>,
47}
48
49impl Default for MD053Config {
50    fn default() -> Self {
51        Self {
52            ignored_definitions: default_ignored_definitions(),
53        }
54    }
55}
56
57fn default_ignored_definitions() -> Vec<String> {
58    Vec::new()
59}
60
61impl RuleConfig for MD053Config {
62    const RULE_NAME: &'static str = "MD053";
63}
64
65/// Rule MD053: Link and image reference definitions should be used
66///
67/// See [docs/md053.md](../../docs/md053.md) for full documentation, configuration, and examples.
68///
69/// This rule is triggered when a link or image reference definition is declared but not used
70/// anywhere in the document. Unused reference definitions can create confusion and clutter.
71///
72/// ## Supported Reference Formats
73///
74/// This rule handles the following reference formats:
75///
76/// - **Full reference links/images**: `[text][reference]` or `![text][reference]`
77/// - **Collapsed reference links/images**: `[text][]` or `![text][]`
78/// - **Shortcut reference links**: `[reference]` (must be defined elsewhere)
79/// - **Reference definitions**: `[reference]: URL "Optional Title"`
80/// - **Multi-line reference definitions**:
81///   ```markdown
82///   [reference]: URL
83///      "Optional title continued on next line"
84///   ```
85///
86/// ## Configuration Options
87///
88/// The rule supports the following configuration options:
89///
90/// ```yaml
91/// MD053:
92///   ignored_definitions: []  # List of reference definitions to ignore (never report as unused)
93/// ```
94///
95/// ## Performance Optimizations
96///
97/// This rule implements various performance optimizations for handling large documents:
98///
99/// 1. **Caching**: The rule caches parsed definitions and references based on content hashing
100/// 2. **Efficient Reference Matching**: Uses HashMaps for O(1) lookups of definitions
101/// 3. **Smart Code Block Handling**: Efficiently skips references inside code blocks/spans
102/// 4. **Lazy Evaluation**: Only processes necessary portions of the document
103///
104/// ## Edge Cases Handled
105///
106/// - **Case insensitivity**: References are matched case-insensitively
107/// - **Escaped characters**: Properly processes escaped characters in references
108/// - **Unicode support**: Handles non-ASCII characters in references and URLs
109/// - **Code blocks**: Ignores references inside code blocks and spans
110/// - **Special characters**: Properly handles references with special characters
111///
112/// ## Fix Behavior
113///
114/// This rule does not provide automatic fixes. Unused references must be manually reviewed
115/// and removed, as they may be intentionally kept for future use or as templates.
116#[derive(Clone)]
117pub struct MD053LinkImageReferenceDefinitions {
118    config: MD053Config,
119}
120
121impl MD053LinkImageReferenceDefinitions {
122    /// Create a new instance of the MD053 rule
123    pub fn new() -> Self {
124        Self {
125            config: MD053Config::default(),
126        }
127    }
128
129    /// Create a new instance with the given configuration
130    pub fn from_config_struct(config: MD053Config) -> Self {
131        Self { config }
132    }
133
134    /// Check if a pattern is likely NOT a markdown reference
135    /// Returns true if this pattern should be skipped
136    fn is_likely_not_reference(text: &str) -> bool {
137        // Don't skip pure numeric patterns - they could be footnote references like [1]
138        // Only skip numeric ranges like [1:3], [0:10], etc.
139        if text.contains(':') && text.chars().all(|c| c.is_ascii_digit() || c == ':') {
140            return true;
141        }
142
143        // Skip glob/wildcard patterns like [*], [...], [**]
144        if text == "*" || text == "..." || text == "**" {
145            return true;
146        }
147
148        // Skip patterns that are just punctuation or operators
149        if text.chars().all(|c| !c.is_alphanumeric() && c != ' ') {
150            return true;
151        }
152
153        // Skip very short non-word patterns (likely operators or syntax)
154        // But allow single digits (could be footnotes) and single letters
155        if text.len() <= 2 && !text.chars().all(|c| c.is_alphanumeric()) {
156            return true;
157        }
158
159        // Skip descriptive patterns with colon like [default: the project root]
160        // But allow simple numeric ranges which are handled above
161        if text.contains(':') && text.contains(' ') {
162            return true;
163        }
164
165        // Skip alert/admonition patterns like [!WARN], [!NOTE], etc.
166        if text.starts_with('!') {
167            return true;
168        }
169
170        false
171    }
172
173    /// Unescape a reference string by removing backslashes before special characters.
174    ///
175    /// This allows matching references like `[example\-reference]` with definitions like
176    /// `[example-reference]: http://example.com`
177    ///
178    /// Returns the unescaped reference string.
179    fn unescape_reference(reference: &str) -> String {
180        // Remove backslashes before special characters
181        reference.replace("\\", "")
182    }
183
184    /// Find all link and image reference definitions in the content.
185    ///
186    /// This method returns a HashMap where the key is the normalized reference ID and the value is a vector of (start_line, end_line) tuples.
187    fn find_definitions(
188        &self,
189        ctx: &crate::lint_context::LintContext,
190        doc_structure: &DocumentStructure,
191    ) -> HashMap<String, Vec<(usize, usize)>> {
192        let mut definitions: HashMap<String, Vec<(usize, usize)>> = HashMap::new();
193
194        // First, add all reference definitions from context
195        for ref_def in &ctx.reference_defs {
196            // Apply unescape to handle escaped characters in definitions
197            let normalized_id = Self::unescape_reference(&ref_def.id); // Already lowercase from context
198            definitions
199                .entry(normalized_id)
200                .or_default()
201                .push((ref_def.line - 1, ref_def.line - 1)); // Convert to 0-indexed
202        }
203
204        // Handle multi-line definitions that might not be fully captured by ctx.reference_defs
205        let lines = &ctx.lines;
206        let mut i = 0;
207        while i < lines.len() {
208            let line_info = &lines[i];
209            let line = &line_info.content;
210
211            // Skip code blocks and front matter using line info
212            if line_info.in_code_block || doc_structure.is_in_front_matter(i + 1) {
213                i += 1;
214                continue;
215            }
216
217            // Check for multi-line continuation of existing definitions
218            if i > 0 && CONTINUATION_REGEX.is_match(line) {
219                // Find the reference definition this continues
220                let mut def_start = i - 1;
221                while def_start > 0 && !REFERENCE_DEFINITION_REGEX.is_match(&lines[def_start].content) {
222                    def_start -= 1;
223                }
224
225                if let Some(caps) = REFERENCE_DEFINITION_REGEX.captures(&lines[def_start].content) {
226                    let ref_id = caps.get(1).unwrap().as_str().trim();
227                    let normalized_id = Self::unescape_reference(ref_id).to_lowercase();
228
229                    // Update the end line for this definition
230                    if let Some(ranges) = definitions.get_mut(&normalized_id)
231                        && let Some(last_range) = ranges.last_mut()
232                        && last_range.0 == def_start
233                    {
234                        last_range.1 = i;
235                    }
236                }
237            }
238            i += 1;
239        }
240        definitions
241    }
242
243    /// Find all link and image reference reference usages in the content.
244    ///
245    /// This method returns a HashSet of all normalized reference IDs found in usage.
246    /// It leverages cached data from LintContext for efficiency.
247    fn find_usages(
248        &self,
249        doc_structure: &DocumentStructure,
250        ctx: &crate::lint_context::LintContext,
251    ) -> HashSet<String> {
252        let mut usages: HashSet<String> = HashSet::new();
253
254        // 1. Add usages from cached reference links in LintContext
255        for link in &ctx.links {
256            if link.is_reference
257                && let Some(ref_id) = &link.reference_id
258            {
259                // Ensure the link itself is not inside a code block line
260                if !doc_structure.is_in_code_block(link.line) {
261                    usages.insert(Self::unescape_reference(ref_id).to_lowercase());
262                }
263            }
264        }
265
266        // 2. Add usages from cached reference images in LintContext
267        for image in &ctx.images {
268            if image.is_reference
269                && let Some(ref_id) = &image.reference_id
270            {
271                // Ensure the image itself is not inside a code block line
272                if !doc_structure.is_in_code_block(image.line) {
273                    usages.insert(Self::unescape_reference(ref_id).to_lowercase());
274                }
275            }
276        }
277
278        // 3. Find shortcut references [ref] not already handled by DocumentStructure.links
279        //    and ensure they are not within code spans or code blocks.
280        // Cache code spans once before the loop
281        let code_spans = ctx.code_spans();
282
283        for (i, line_info) in ctx.lines.iter().enumerate() {
284            let line_num = i + 1; // 1-indexed
285
286            // Skip lines in code blocks or front matter
287            if line_info.in_code_block || doc_structure.is_in_front_matter(line_num) {
288                continue;
289            }
290
291            // Skip lines that are reference definitions (start with [ref]: at beginning)
292            if REFERENCE_DEFINITION_REGEX.is_match(&line_info.content) {
293                continue;
294            }
295
296            // Find potential shortcut references
297            for caps in SHORTCUT_REFERENCE_REGEX.captures_iter(&line_info.content).flatten() {
298                if let Some(full_match) = caps.get(0)
299                    && let Some(ref_id_match) = caps.get(1)
300                {
301                    // Check if the match is within a code span
302                    let match_byte_offset = line_info.byte_offset + full_match.start();
303                    let in_code_span = code_spans
304                        .iter()
305                        .any(|span| match_byte_offset >= span.byte_offset && match_byte_offset < span.byte_end);
306
307                    if !in_code_span {
308                        let ref_id = ref_id_match.as_str().trim();
309
310                        // Skip patterns that are likely not markdown references
311                        if !Self::is_likely_not_reference(ref_id) {
312                            let normalized_id = Self::unescape_reference(ref_id).to_lowercase();
313                            usages.insert(normalized_id);
314                        }
315                    }
316                }
317            }
318        }
319
320        // NOTE: The complex recursive loop trying to find references within definitions
321        // has been removed as it's not standard Markdown behavior for finding *usages*.
322        // Usages refer to `[text][ref]`, `![alt][ref]`, `[ref]`, etc., in the main content,
323        // not references potentially embedded within the URL or title of another definition.
324
325        usages
326    }
327
328    /// Get unused references with their line ranges.
329    ///
330    /// This method uses the cached definitions to improve performance.
331    ///
332    /// Note: References that are only used inside code blocks are still considered unused,
333    /// as code blocks are treated as examples or documentation rather than actual content.
334    fn get_unused_references(
335        &self,
336        definitions: &HashMap<String, Vec<(usize, usize)>>,
337        usages: &HashSet<String>,
338    ) -> Vec<(String, usize, usize)> {
339        let mut unused = Vec::new();
340        for (id, ranges) in definitions {
341            // If this id is not used anywhere and is not in the ignored list, all its ranges are unused
342            if !usages.contains(id) && !self.is_ignored_definition(id) {
343                for (start, end) in ranges {
344                    unused.push((id.clone(), *start, *end));
345                }
346            }
347        }
348        unused
349    }
350
351    /// Check if a definition should be ignored (kept even if unused)
352    fn is_ignored_definition(&self, definition_id: &str) -> bool {
353        self.config
354            .ignored_definitions
355            .iter()
356            .any(|ignored| ignored.eq_ignore_ascii_case(definition_id))
357    }
358}
359
360impl Default for MD053LinkImageReferenceDefinitions {
361    fn default() -> Self {
362        Self::new()
363    }
364}
365
366impl Rule for MD053LinkImageReferenceDefinitions {
367    fn name(&self) -> &'static str {
368        "MD053"
369    }
370
371    fn description(&self) -> &'static str {
372        "Link and image reference definitions should be needed"
373    }
374
375    /// Check the content for unused and duplicate link/image reference definitions.
376    ///
377    /// This implementation uses caching for improved performance on large documents.
378    fn check(&self, ctx: &crate::lint_context::LintContext) -> LintResult {
379        let content = ctx.content;
380        // Compute DocumentStructure once
381        let doc_structure = DocumentStructure::new(content);
382
383        // Find definitions and usages using DocumentStructure
384        let definitions = self.find_definitions(ctx, &doc_structure);
385        let usages = self.find_usages(&doc_structure, ctx);
386
387        // Get unused references by comparing definitions and usages
388        let unused_refs = self.get_unused_references(&definitions, &usages);
389
390        let mut warnings = Vec::new();
391
392        // Check for duplicate definitions (case-insensitive per CommonMark spec)
393        let mut seen_definitions: HashMap<String, (String, usize)> = HashMap::new(); // lowercase -> (original, first_line)
394
395        for (definition_id, ranges) in &definitions {
396            // Skip ignored definitions for duplicate checking
397            if self.is_ignored_definition(definition_id) {
398                continue;
399            }
400
401            if ranges.len() > 1 {
402                // Multiple definitions with exact same ID (already lowercase)
403                for (i, &(start_line, _)) in ranges.iter().enumerate() {
404                    if i > 0 {
405                        // Skip the first occurrence, report all others
406                        let line_num = start_line + 1;
407                        let line_content = ctx.lines.get(start_line).map(|l| l.content.as_str()).unwrap_or("");
408                        let (start_line_1idx, start_col, end_line, end_col) =
409                            calculate_line_range(line_num, line_content);
410
411                        warnings.push(LintWarning {
412                            rule_name: Some(self.name()),
413                            line: start_line_1idx,
414                            column: start_col,
415                            end_line,
416                            end_column: end_col,
417                            message: format!("Duplicate link or image reference definition: [{definition_id}]"),
418                            severity: Severity::Warning,
419                            fix: None,
420                        });
421                    }
422                }
423            }
424
425            // Track for case-variant duplicates
426            if let Some(&(start_line, _)) = ranges.first() {
427                // Find the original case version from the line
428                if let Some(line_info) = ctx.lines.get(start_line)
429                    && let Some(caps) = REFERENCE_DEFINITION_REGEX.captures(&line_info.content)
430                {
431                    let original_id = caps.get(1).unwrap().as_str().trim();
432                    let lower_id = original_id.to_lowercase();
433
434                    if let Some((first_original, first_line)) = seen_definitions.get(&lower_id) {
435                        // Found a case-variant duplicate
436                        if first_original != original_id {
437                            let line_num = start_line + 1;
438                            let line_content = &line_info.content;
439                            let (start_line_1idx, start_col, end_line, end_col) =
440                                calculate_line_range(line_num, line_content);
441
442                            warnings.push(LintWarning {
443                                    rule_name: Some(self.name()),
444                                    line: start_line_1idx,
445                                    column: start_col,
446                                    end_line,
447                                    end_column: end_col,
448                                    message: format!("Duplicate link or image reference definition: [{}] (conflicts with [{}] on line {})",
449                                                   original_id, first_original, first_line + 1),
450                                    severity: Severity::Warning,
451                                    fix: None,
452                                });
453                        }
454                    } else {
455                        seen_definitions.insert(lower_id, (original_id.to_string(), start_line));
456                    }
457                }
458            }
459        }
460
461        // Create warnings for unused references
462        for (definition, start, _end) in unused_refs {
463            let line_num = start + 1; // 1-indexed line numbers
464            let line_content = ctx.lines.get(start).map(|l| l.content.as_str()).unwrap_or("");
465
466            // Calculate precise character range for the entire reference definition line
467            let (start_line, start_col, end_line, end_col) = calculate_line_range(line_num, line_content);
468
469            warnings.push(LintWarning {
470                rule_name: Some(self.name()),
471                line: start_line,
472                column: start_col,
473                end_line,
474                end_column: end_col,
475                message: format!("Unused link/image reference: [{definition}]"),
476                severity: Severity::Warning,
477                fix: None, // MD053 is warning-only, no automatic fixes
478            });
479        }
480
481        Ok(warnings)
482    }
483
484    /// MD053 does not provide automatic fixes
485    fn fix(&self, ctx: &crate::lint_context::LintContext) -> Result<String, LintError> {
486        // This rule is warning-only, no automatic fixes provided
487        Ok(ctx.content.to_string())
488    }
489
490    /// Check if this rule should be skipped for performance
491    fn should_skip(&self, ctx: &crate::lint_context::LintContext) -> bool {
492        // Skip if content is empty or has no reference definitions
493        ctx.content.is_empty() || !ctx.content.contains("]:")
494    }
495
496    fn as_any(&self) -> &dyn std::any::Any {
497        self
498    }
499
500    fn default_config_section(&self) -> Option<(String, toml::Value)> {
501        let default_config = MD053Config::default();
502        let json_value = serde_json::to_value(&default_config).ok()?;
503        let toml_value = crate::rule_config_serde::json_to_toml_value(&json_value)?;
504        if let toml::Value::Table(table) = toml_value {
505            if !table.is_empty() {
506                Some((MD053Config::RULE_NAME.to_string(), toml::Value::Table(table)))
507            } else {
508                None
509            }
510        } else {
511            None
512        }
513    }
514
515    fn from_config(config: &crate::config::Config) -> Box<dyn Rule>
516    where
517        Self: Sized,
518    {
519        let rule_config = crate::rule_config_serde::load_rule_config::<MD053Config>(config);
520        Box::new(MD053LinkImageReferenceDefinitions::from_config_struct(rule_config))
521    }
522}
523
524#[cfg(test)]
525mod tests {
526    use super::*;
527    use crate::lint_context::LintContext;
528
529    #[test]
530    fn test_used_reference_link() {
531        let rule = MD053LinkImageReferenceDefinitions::new();
532        let content = "[text][ref]\n\n[ref]: https://example.com";
533        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
534        let result = rule.check(&ctx).unwrap();
535
536        assert_eq!(result.len(), 0);
537    }
538
539    #[test]
540    fn test_unused_reference_definition() {
541        let rule = MD053LinkImageReferenceDefinitions::new();
542        let content = "[unused]: https://example.com";
543        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
544        let result = rule.check(&ctx).unwrap();
545
546        assert_eq!(result.len(), 1);
547        assert!(result[0].message.contains("Unused link/image reference: [unused]"));
548    }
549
550    #[test]
551    fn test_used_reference_image() {
552        let rule = MD053LinkImageReferenceDefinitions::new();
553        let content = "![alt][img]\n\n[img]: image.jpg";
554        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
555        let result = rule.check(&ctx).unwrap();
556
557        assert_eq!(result.len(), 0);
558    }
559
560    #[test]
561    fn test_case_insensitive_matching() {
562        let rule = MD053LinkImageReferenceDefinitions::new();
563        let content = "[Text][REF]\n\n[ref]: https://example.com";
564        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
565        let result = rule.check(&ctx).unwrap();
566
567        assert_eq!(result.len(), 0);
568    }
569
570    #[test]
571    fn test_shortcut_reference() {
572        let rule = MD053LinkImageReferenceDefinitions::new();
573        let content = "[ref]\n\n[ref]: https://example.com";
574        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
575        let result = rule.check(&ctx).unwrap();
576
577        assert_eq!(result.len(), 0);
578    }
579
580    #[test]
581    fn test_collapsed_reference() {
582        let rule = MD053LinkImageReferenceDefinitions::new();
583        let content = "[ref][]\n\n[ref]: https://example.com";
584        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
585        let result = rule.check(&ctx).unwrap();
586
587        assert_eq!(result.len(), 0);
588    }
589
590    #[test]
591    fn test_multiple_unused_definitions() {
592        let rule = MD053LinkImageReferenceDefinitions::new();
593        let content = "[unused1]: url1\n[unused2]: url2\n[unused3]: url3";
594        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
595        let result = rule.check(&ctx).unwrap();
596
597        assert_eq!(result.len(), 3);
598
599        // The warnings might not be in the same order, so collect all messages
600        let messages: Vec<String> = result.iter().map(|w| w.message.clone()).collect();
601        assert!(messages.iter().any(|m| m.contains("unused1")));
602        assert!(messages.iter().any(|m| m.contains("unused2")));
603        assert!(messages.iter().any(|m| m.contains("unused3")));
604    }
605
606    #[test]
607    fn test_mixed_used_and_unused() {
608        let rule = MD053LinkImageReferenceDefinitions::new();
609        let content = "[used]\n\n[used]: url1\n[unused]: url2";
610        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
611        let result = rule.check(&ctx).unwrap();
612
613        assert_eq!(result.len(), 1);
614        assert!(result[0].message.contains("unused"));
615    }
616
617    #[test]
618    fn test_multiline_definition() {
619        let rule = MD053LinkImageReferenceDefinitions::new();
620        let content = "[ref]: https://example.com\n  \"Title on next line\"";
621        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
622        let result = rule.check(&ctx).unwrap();
623
624        assert_eq!(result.len(), 1); // Still unused
625    }
626
627    #[test]
628    fn test_reference_in_code_block() {
629        let rule = MD053LinkImageReferenceDefinitions::new();
630        let content = "```\n[ref]\n```\n\n[ref]: https://example.com";
631        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
632        let result = rule.check(&ctx).unwrap();
633
634        // Reference used only in code block is still considered unused
635        assert_eq!(result.len(), 1);
636    }
637
638    #[test]
639    fn test_reference_in_inline_code() {
640        let rule = MD053LinkImageReferenceDefinitions::new();
641        let content = "`[ref]`\n\n[ref]: https://example.com";
642        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
643        let result = rule.check(&ctx).unwrap();
644
645        // Reference in inline code is not a usage
646        assert_eq!(result.len(), 1);
647    }
648
649    #[test]
650    fn test_escaped_reference() {
651        let rule = MD053LinkImageReferenceDefinitions::new();
652        let content = "[example\\-ref]\n\n[example-ref]: https://example.com";
653        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
654        let result = rule.check(&ctx).unwrap();
655
656        // Should match despite escaping
657        assert_eq!(result.len(), 0);
658    }
659
660    #[test]
661    fn test_duplicate_definitions() {
662        let rule = MD053LinkImageReferenceDefinitions::new();
663        let content = "[ref]: url1\n[ref]: url2\n\n[ref]";
664        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
665        let result = rule.check(&ctx).unwrap();
666
667        // Should flag the duplicate definition even though it's used (matches markdownlint)
668        assert_eq!(result.len(), 1);
669    }
670
671    #[test]
672    fn test_fix_returns_original() {
673        // MD053 is warning-only, fix should return original content
674        let rule = MD053LinkImageReferenceDefinitions::new();
675        let content = "[used]\n\n[used]: url1\n[unused]: url2\n\nMore content";
676        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
677        let fixed = rule.fix(&ctx).unwrap();
678
679        assert_eq!(fixed, content);
680    }
681
682    #[test]
683    fn test_fix_preserves_content() {
684        // MD053 is warning-only, fix should preserve all content
685        let rule = MD053LinkImageReferenceDefinitions::new();
686        let content = "Content\n\n[unused]: url\n\nMore content";
687        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
688        let fixed = rule.fix(&ctx).unwrap();
689
690        assert_eq!(fixed, content);
691    }
692
693    #[test]
694    fn test_fix_does_not_remove() {
695        // MD053 is warning-only, fix should not remove anything
696        let rule = MD053LinkImageReferenceDefinitions::new();
697        let content = "[unused1]: url1\n[unused2]: url2\n[unused3]: url3";
698        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
699        let fixed = rule.fix(&ctx).unwrap();
700
701        assert_eq!(fixed, content);
702    }
703
704    #[test]
705    fn test_special_characters_in_reference() {
706        let rule = MD053LinkImageReferenceDefinitions::new();
707        let content = "[ref-with_special.chars]\n\n[ref-with_special.chars]: url";
708        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
709        let result = rule.check(&ctx).unwrap();
710
711        assert_eq!(result.len(), 0);
712    }
713
714    #[test]
715    fn test_find_definitions() {
716        let rule = MD053LinkImageReferenceDefinitions::new();
717        let content = "[ref1]: url1\n[ref2]: url2\nSome text\n[ref3]: url3";
718        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
719        let doc = DocumentStructure::new(content);
720        let defs = rule.find_definitions(&ctx, &doc);
721
722        assert_eq!(defs.len(), 3);
723        assert!(defs.contains_key("ref1"));
724        assert!(defs.contains_key("ref2"));
725        assert!(defs.contains_key("ref3"));
726    }
727
728    #[test]
729    fn test_find_usages() {
730        let rule = MD053LinkImageReferenceDefinitions::new();
731        let content = "[text][ref1] and [ref2] and ![img][ref3]";
732        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
733        let doc = DocumentStructure::new(content);
734        let usages = rule.find_usages(&doc, &ctx);
735
736        assert!(usages.contains("ref1"));
737        assert!(usages.contains("ref2"));
738        assert!(usages.contains("ref3"));
739    }
740
741    #[test]
742    fn test_ignored_definitions_config() {
743        // Test with ignored definitions
744        let config = MD053Config {
745            ignored_definitions: vec!["todo".to_string(), "draft".to_string()],
746        };
747        let rule = MD053LinkImageReferenceDefinitions::from_config_struct(config);
748
749        let content = "[todo]: https://example.com/todo\n[draft]: https://example.com/draft\n[unused]: https://example.com/unused";
750        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
751        let result = rule.check(&ctx).unwrap();
752
753        // Should only flag "unused", not "todo" or "draft"
754        assert_eq!(result.len(), 1);
755        assert!(result[0].message.contains("unused"));
756        assert!(!result[0].message.contains("todo"));
757        assert!(!result[0].message.contains("draft"));
758    }
759
760    #[test]
761    fn test_ignored_definitions_case_insensitive() {
762        // Test case-insensitive matching of ignored definitions
763        let config = MD053Config {
764            ignored_definitions: vec!["TODO".to_string()],
765        };
766        let rule = MD053LinkImageReferenceDefinitions::from_config_struct(config);
767
768        let content = "[todo]: https://example.com/todo\n[unused]: https://example.com/unused";
769        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
770        let result = rule.check(&ctx).unwrap();
771
772        // Should only flag "unused", not "todo" (matches "TODO" case-insensitively)
773        assert_eq!(result.len(), 1);
774        assert!(result[0].message.contains("unused"));
775        assert!(!result[0].message.contains("todo"));
776    }
777
778    #[test]
779    fn test_default_config_section() {
780        let rule = MD053LinkImageReferenceDefinitions::default();
781        let config_section = rule.default_config_section();
782
783        assert!(config_section.is_some());
784        let (name, value) = config_section.unwrap();
785        assert_eq!(name, "MD053");
786
787        // Should contain the ignored_definitions option with default empty array
788        if let toml::Value::Table(table) = value {
789            assert!(table.contains_key("ignored-definitions"));
790            assert_eq!(table["ignored-definitions"], toml::Value::Array(vec![]));
791        } else {
792            panic!("Expected TOML table");
793        }
794    }
795
796    #[test]
797    fn test_fix_with_ignored_definitions() {
798        // MD053 is warning-only, fix should not remove anything even with ignored definitions
799        let config = MD053Config {
800            ignored_definitions: vec!["template".to_string()],
801        };
802        let rule = MD053LinkImageReferenceDefinitions::from_config_struct(config);
803
804        let content = "[template]: https://example.com/template\n[unused]: https://example.com/unused\n\nSome content.";
805        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
806        let fixed = rule.fix(&ctx).unwrap();
807
808        // Should keep everything since MD053 doesn't fix
809        assert_eq!(fixed, content);
810    }
811
812    #[test]
813    fn test_duplicate_definitions_exact_case() {
814        let rule = MD053LinkImageReferenceDefinitions::new();
815        let content = "[ref]: url1\n[ref]: url2\n[ref]: url3";
816        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
817        let result = rule.check(&ctx).unwrap();
818
819        // Should have 2 duplicate warnings (for the 2nd and 3rd definitions)
820        // Plus 1 unused warning
821        let duplicate_warnings: Vec<_> = result.iter().filter(|w| w.message.contains("Duplicate")).collect();
822        assert_eq!(duplicate_warnings.len(), 2);
823        assert_eq!(duplicate_warnings[0].line, 2);
824        assert_eq!(duplicate_warnings[1].line, 3);
825    }
826
827    #[test]
828    fn test_duplicate_definitions_case_variants() {
829        let rule = MD053LinkImageReferenceDefinitions::new();
830        let content =
831            "[method resolution order]: url1\n[Method Resolution Order]: url2\n[METHOD RESOLUTION ORDER]: url3";
832        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
833        let result = rule.check(&ctx).unwrap();
834
835        // Should have 2 duplicate warnings (for the 2nd and 3rd definitions)
836        // Note: These are treated as exact duplicates since they normalize to the same ID
837        let duplicate_warnings: Vec<_> = result.iter().filter(|w| w.message.contains("Duplicate")).collect();
838        assert_eq!(duplicate_warnings.len(), 2);
839
840        // The exact duplicate messages don't include "conflicts with"
841        // Only case-variant duplicates with different normalized forms would
842        assert_eq!(duplicate_warnings[0].line, 2);
843        assert_eq!(duplicate_warnings[1].line, 3);
844    }
845
846    #[test]
847    fn test_duplicate_and_unused() {
848        let rule = MD053LinkImageReferenceDefinitions::new();
849        let content = "[used]\n[used]: url1\n[used]: url2\n[unused]: url3";
850        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
851        let result = rule.check(&ctx).unwrap();
852
853        // Should have 1 duplicate warning and 1 unused warning
854        let duplicate_warnings: Vec<_> = result.iter().filter(|w| w.message.contains("Duplicate")).collect();
855        let unused_warnings: Vec<_> = result.iter().filter(|w| w.message.contains("Unused")).collect();
856
857        assert_eq!(duplicate_warnings.len(), 1);
858        assert_eq!(unused_warnings.len(), 1);
859        assert_eq!(duplicate_warnings[0].line, 3); // Second [used] definition
860        assert_eq!(unused_warnings[0].line, 4); // [unused] definition
861    }
862
863    #[test]
864    fn test_duplicate_with_usage() {
865        let rule = MD053LinkImageReferenceDefinitions::new();
866        // Even if used, duplicates should still be reported
867        let content = "[ref]\n\n[ref]: url1\n[ref]: url2";
868        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
869        let result = rule.check(&ctx).unwrap();
870
871        // Should have 1 duplicate warning (no unused since it's referenced)
872        let duplicate_warnings: Vec<_> = result.iter().filter(|w| w.message.contains("Duplicate")).collect();
873        let unused_warnings: Vec<_> = result.iter().filter(|w| w.message.contains("Unused")).collect();
874
875        assert_eq!(duplicate_warnings.len(), 1);
876        assert_eq!(unused_warnings.len(), 0);
877        assert_eq!(duplicate_warnings[0].line, 4);
878    }
879
880    #[test]
881    fn test_no_duplicate_different_ids() {
882        let rule = MD053LinkImageReferenceDefinitions::new();
883        let content = "[ref1]: url1\n[ref2]: url2\n[ref3]: url3";
884        let ctx = LintContext::new(content, crate::config::MarkdownFlavor::Standard);
885        let result = rule.check(&ctx).unwrap();
886
887        // Should have no duplicate warnings, only unused warnings
888        let duplicate_warnings: Vec<_> = result.iter().filter(|w| w.message.contains("Duplicate")).collect();
889        assert_eq!(duplicate_warnings.len(), 0);
890    }
891}
rumdl_lib/rules/md053_link_image_reference_definitions.rs

rumdl_lib/rules/
md053_link_image_reference_definitions.rs
