fallow-types 2.95.0

Shared types and serde paths for fallow codebase intelligence
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
//! Inline suppression comment types and issue kind definitions.

/// Issue kind for suppression matching.
///
/// # Examples
///
/// ```
/// use fallow_types::suppress::IssueKind;
///
/// let kind = IssueKind::parse("unused-export");
/// assert_eq!(kind, Some(IssueKind::UnusedExport));
///
/// // Round-trip through discriminant
/// let d = IssueKind::UnusedFile.to_discriminant();
/// assert_eq!(IssueKind::from_discriminant(d), Some(IssueKind::UnusedFile));
///
/// // Unknown strings return None
/// assert_eq!(IssueKind::parse("not-a-kind"), None);
/// ```
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum IssueKind {
    /// An unused file.
    UnusedFile,
    /// An unused export.
    UnusedExport,
    /// An unused type export.
    UnusedType,
    /// An exported signature that references a same-file private type.
    PrivateTypeLeak,
    /// An unused dependency.
    UnusedDependency,
    /// An unused dev dependency.
    UnusedDevDependency,
    /// An unused enum member.
    UnusedEnumMember,
    /// An unused class member.
    UnusedClassMember,
    /// An unresolved import.
    UnresolvedImport,
    /// An unlisted dependency.
    UnlistedDependency,
    /// A duplicate export name across modules.
    DuplicateExport,
    /// Code duplication.
    CodeDuplication,
    /// A circular dependency chain.
    CircularDependency,
    /// A cycle or self-loop in the re-export edge subgraph (barrel files
    /// re-exporting from each other in a loop). Structurally always a bug:
    /// chain propagation through the cycle is a no-op.
    ReExportCycle,
    /// A production dependency only imported via type-only imports.
    TypeOnlyDependency,
    /// A production dependency only imported by test files.
    TestOnlyDependency,
    /// An import that crosses an architecture boundary.
    BoundaryViolation,
    /// A runtime file or export with no test dependency path.
    CoverageGaps,
    /// A detected feature flag pattern.
    FeatureFlag,
    /// A function exceeding complexity thresholds (health command).
    Complexity,
    /// A suppression comment or JSDoc tag that no longer matches any issue.
    StaleSuppression,
    /// A pnpm catalog entry in pnpm-workspace.yaml not referenced by any workspace package.
    PnpmCatalogEntry,
    /// A named pnpm catalog group in pnpm-workspace.yaml with no entries.
    EmptyCatalogGroup,
    /// A workspace package.json reference (`catalog:` / `catalog:<name>`) pointing at
    /// a catalog that does not declare the consumed package.
    UnresolvedCatalogReference,
    /// An entry in pnpm's `overrides:` / `pnpm.overrides` whose target package
    /// is not declared in any workspace `package.json`.
    UnusedDependencyOverride,
    /// An entry in pnpm's `overrides:` / `pnpm.overrides` whose key or value
    /// cannot be parsed into a valid pnpm shape.
    MisconfiguredDependencyOverride,
    /// A `"use client"` file that transitively imports a module reading a
    /// non-public `process.env` secret (security candidate).
    SecurityClientServerLeak,
    /// A syntactic tainted-sink candidate matched against the data-driven
    /// security matcher catalogue (`security_matchers.toml`). ONE suppression
    /// token covers all catalogue categories.
    SecuritySink,
    /// A banned call or banned import matched by a declarative rule pack
    /// (`rulePacks` config). The bare token covers every pack rule; scoped
    /// tokens can target one `<pack>/<rule-id>` identity.
    PolicyViolation,
}

impl IssueKind {
    /// Parse an issue kind from the string tokens used in CLI output and suppression comments.
    #[must_use]
    pub fn parse(s: &str) -> Option<Self> {
        match s {
            "unused-file" => Some(Self::UnusedFile),
            "unused-export" => Some(Self::UnusedExport),
            "unused-type" => Some(Self::UnusedType),
            "private-type-leak" => Some(Self::PrivateTypeLeak),
            "unused-dependency" => Some(Self::UnusedDependency),
            "unused-dev-dependency" => Some(Self::UnusedDevDependency),
            "unused-enum-member" => Some(Self::UnusedEnumMember),
            "unused-class-member" => Some(Self::UnusedClassMember),
            "unresolved-import" => Some(Self::UnresolvedImport),
            "unlisted-dependency" => Some(Self::UnlistedDependency),
            "duplicate-export" => Some(Self::DuplicateExport),
            "code-duplication" => Some(Self::CodeDuplication),
            "circular-dependency" | "circular-dependencies" => Some(Self::CircularDependency),
            "re-export-cycle" | "re-export-cycles" | "reexport-cycle" | "reexport-cycles" => {
                Some(Self::ReExportCycle)
            }
            "type-only-dependency" => Some(Self::TypeOnlyDependency),
            "test-only-dependency" => Some(Self::TestOnlyDependency),
            "boundary-violation" | "boundary-call-violation" | "boundary-call-violations" => {
                Some(Self::BoundaryViolation)
            }
            "coverage-gaps" => Some(Self::CoverageGaps),
            "feature-flag" => Some(Self::FeatureFlag),
            "complexity" => Some(Self::Complexity),
            "stale-suppression" => Some(Self::StaleSuppression),
            "unused-catalog-entry" | "unused-catalog-entries" => Some(Self::PnpmCatalogEntry),
            "empty-catalog-group" | "empty-catalog-groups" => Some(Self::EmptyCatalogGroup),
            "unresolved-catalog-reference" | "unresolved-catalog-references" => {
                Some(Self::UnresolvedCatalogReference)
            }
            "unused-dependency-override" | "unused-dependency-overrides" => {
                Some(Self::UnusedDependencyOverride)
            }
            "misconfigured-dependency-override" | "misconfigured-dependency-overrides" => {
                Some(Self::MisconfiguredDependencyOverride)
            }
            "security-client-server-leak" => Some(Self::SecurityClientServerLeak),
            "security-sink" => Some(Self::SecuritySink),
            "policy-violation" | "policy-violations" => Some(Self::PolicyViolation),
            _ => None,
        }
    }

    /// Convert to a u8 discriminant for compact cache storage.
    #[must_use]
    pub const fn to_discriminant(self) -> u8 {
        match self {
            Self::UnusedFile => 1,
            Self::UnusedExport => 2,
            Self::UnusedType => 3,
            Self::PrivateTypeLeak => 4,
            Self::UnusedDependency => 5,
            Self::UnusedDevDependency => 6,
            Self::UnusedEnumMember => 7,
            Self::UnusedClassMember => 8,
            Self::UnresolvedImport => 9,
            Self::UnlistedDependency => 10,
            Self::DuplicateExport => 11,
            Self::CodeDuplication => 12,
            Self::CircularDependency => 13,
            Self::TypeOnlyDependency => 14,
            Self::TestOnlyDependency => 15,
            Self::BoundaryViolation => 16,
            Self::CoverageGaps => 17,
            Self::FeatureFlag => 18,
            Self::Complexity => 19,
            Self::StaleSuppression => 20,
            Self::PnpmCatalogEntry => 21,
            Self::UnresolvedCatalogReference => 22,
            Self::UnusedDependencyOverride => 23,
            Self::MisconfiguredDependencyOverride => 24,
            Self::EmptyCatalogGroup => 25,
            Self::ReExportCycle => 26,
            Self::SecurityClientServerLeak => 27,
            Self::SecuritySink => 28,
            Self::PolicyViolation => 29,
        }
    }

    /// Reconstruct from a cache discriminant.
    #[must_use]
    pub const fn from_discriminant(d: u8) -> Option<Self> {
        match d {
            1 => Some(Self::UnusedFile),
            2 => Some(Self::UnusedExport),
            3 => Some(Self::UnusedType),
            4 => Some(Self::PrivateTypeLeak),
            5 => Some(Self::UnusedDependency),
            6 => Some(Self::UnusedDevDependency),
            7 => Some(Self::UnusedEnumMember),
            8 => Some(Self::UnusedClassMember),
            9 => Some(Self::UnresolvedImport),
            10 => Some(Self::UnlistedDependency),
            11 => Some(Self::DuplicateExport),
            12 => Some(Self::CodeDuplication),
            13 => Some(Self::CircularDependency),
            14 => Some(Self::TypeOnlyDependency),
            15 => Some(Self::TestOnlyDependency),
            16 => Some(Self::BoundaryViolation),
            17 => Some(Self::CoverageGaps),
            18 => Some(Self::FeatureFlag),
            19 => Some(Self::Complexity),
            20 => Some(Self::StaleSuppression),
            21 => Some(Self::PnpmCatalogEntry),
            22 => Some(Self::UnresolvedCatalogReference),
            23 => Some(Self::UnusedDependencyOverride),
            24 => Some(Self::MisconfiguredDependencyOverride),
            25 => Some(Self::EmptyCatalogGroup),
            26 => Some(Self::ReExportCycle),
            27 => Some(Self::SecurityClientServerLeak),
            28 => Some(Self::SecuritySink),
            29 => Some(Self::PolicyViolation),
            _ => None,
        }
    }
}

/// One scoped rule-pack policy suppression target.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct PolicyRuleSuppression {
    /// Rule-pack name.
    pub pack: String,
    /// Rule id within the pack.
    pub rule_id: String,
}

impl PolicyRuleSuppression {
    /// Build a scoped policy suppression target.
    #[must_use]
    pub fn new(pack: impl Into<String>, rule_id: impl Into<String>) -> Self {
        Self {
            pack: pack.into(),
            rule_id: rule_id.into(),
        }
    }

    /// Canonical suppression token.
    #[must_use]
    pub fn token(&self) -> String {
        format!("policy-violation:{}/{}", self.pack, self.rule_id)
    }
}

/// A specific suppression target parsed from a comment token.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum SuppressionTarget {
    /// A regular issue-kind token such as `unused-export` or bare
    /// `policy-violation`.
    Issue(IssueKind),
    /// A scoped rule-pack policy token such as
    /// `policy-violation:team-policy/no-child-process`.
    PolicyRule(PolicyRuleSuppression),
}

impl SuppressionTarget {
    /// Return the regular issue kind when this target is a bare issue-kind
    /// token.
    #[must_use]
    pub const fn issue_kind(&self) -> Option<IssueKind> {
        match self {
            Self::Issue(kind) => Some(*kind),
            Self::PolicyRule(_) => None,
        }
    }

    /// Canonical suppression token for output and active-suppression capture.
    #[must_use]
    pub fn token(&self) -> String {
        match self {
            Self::Issue(kind) => issue_kind_to_kebab(*kind).to_owned(),
            Self::PolicyRule(rule) => rule.token(),
        }
    }
}

/// Convert an [`IssueKind`] to its canonical suppression token.
#[must_use]
pub const fn issue_kind_to_kebab(kind: IssueKind) -> &'static str {
    match kind {
        IssueKind::UnusedFile => "unused-file",
        IssueKind::UnusedExport => "unused-export",
        IssueKind::UnusedType => "unused-type",
        IssueKind::PrivateTypeLeak => "private-type-leak",
        IssueKind::UnusedDependency => "unused-dependency",
        IssueKind::UnusedDevDependency => "unused-dev-dependency",
        IssueKind::UnusedEnumMember => "unused-enum-member",
        IssueKind::UnusedClassMember => "unused-class-member",
        IssueKind::UnresolvedImport => "unresolved-import",
        IssueKind::UnlistedDependency => "unlisted-dependency",
        IssueKind::DuplicateExport => "duplicate-export",
        IssueKind::CodeDuplication => "code-duplication",
        IssueKind::CircularDependency => "circular-dependency",
        IssueKind::ReExportCycle => "re-export-cycle",
        IssueKind::TypeOnlyDependency => "type-only-dependency",
        IssueKind::TestOnlyDependency => "test-only-dependency",
        IssueKind::BoundaryViolation => "boundary-violation",
        IssueKind::CoverageGaps => "coverage-gaps",
        IssueKind::FeatureFlag => "feature-flag",
        IssueKind::Complexity => "complexity",
        IssueKind::StaleSuppression => "stale-suppression",
        IssueKind::PnpmCatalogEntry => "unused-catalog-entry",
        IssueKind::EmptyCatalogGroup => "empty-catalog-group",
        IssueKind::UnresolvedCatalogReference => "unresolved-catalog-reference",
        IssueKind::UnusedDependencyOverride => "unused-dependency-override",
        IssueKind::MisconfiguredDependencyOverride => "misconfigured-dependency-override",
        IssueKind::SecurityClientServerLeak => "security-client-server-leak",
        IssueKind::SecuritySink => "security-sink",
        IssueKind::PolicyViolation => "policy-violation",
    }
}

/// Parse a suppression token into a structured target.
#[must_use]
pub fn parse_suppression_target(token: &str) -> Option<SuppressionTarget> {
    parse_policy_rule_suppression_token(token)
        .map(SuppressionTarget::PolicyRule)
        .or_else(|| IssueKind::parse(token).map(SuppressionTarget::Issue))
}

/// Parse canonical scoped policy suppression tokens.
///
/// The plural prefix is accepted for consistency with the bare legacy alias,
/// but output always uses singular `policy-violation:`.
#[must_use]
pub fn parse_policy_rule_suppression_token(token: &str) -> Option<PolicyRuleSuppression> {
    let identity = token
        .strip_prefix("policy-violation:")
        .or_else(|| token.strip_prefix("policy-violations:"))?;
    let (pack, rule_id) = identity.split_once('/')?;
    if rule_id.contains('/') {
        return None;
    }
    if !is_valid_policy_identifier(pack) || !is_valid_policy_identifier(rule_id) {
        return None;
    }
    Some(PolicyRuleSuppression::new(pack, rule_id))
}

/// Whether a rule-pack name or rule id can be used inside
/// `policy-violation:<pack>/<rule-id>` without escaping.
#[must_use]
pub fn is_valid_policy_identifier(value: &str) -> bool {
    !value.is_empty()
        && value
            .bytes()
            .all(|b| b.is_ascii_alphanumeric() || matches!(b, b'.' | b'_' | b'-'))
}

/// A suppression directive parsed from a source comment.
///
/// # Examples
///
/// ```
/// use fallow_types::suppress::{Suppression, IssueKind};
///
/// // File-wide suppression (line 0, no specific kind)
/// let file_wide = Suppression::all(0, 1);
/// assert_eq!(file_wide.line, 0);
///
/// // Line-specific suppression for unused exports
/// let line_suppress = Suppression::issue(42, 41, IssueKind::UnusedExport);
/// assert_eq!(line_suppress.issue_kind_target(), Some(IssueKind::UnusedExport));
/// ```
#[derive(Debug, Clone)]
pub struct Suppression {
    /// 1-based line this suppression applies to. 0 = file-wide suppression.
    pub line: u32,
    /// 1-based line where the suppression comment itself appears.
    /// For `fallow-ignore-next-line`, this is `line - 1`.
    /// For `fallow-ignore-file`, this is the actual line of the comment in the source.
    pub comment_line: u32,
    /// None = suppress all issue kinds on this line or file.
    pub target: Option<SuppressionTarget>,
}

impl Suppression {
    /// Build a blanket suppression.
    #[must_use]
    pub const fn all(line: u32, comment_line: u32) -> Self {
        Self {
            line,
            comment_line,
            target: None,
        }
    }

    /// Build a regular issue-kind suppression.
    #[must_use]
    pub const fn issue(line: u32, comment_line: u32, kind: IssueKind) -> Self {
        Self {
            line,
            comment_line,
            target: Some(SuppressionTarget::Issue(kind)),
        }
    }

    /// Build a scoped rule-pack policy suppression.
    #[must_use]
    pub fn policy_rule(
        line: u32,
        comment_line: u32,
        pack: impl Into<String>,
        rule_id: impl Into<String>,
    ) -> Self {
        Self {
            line,
            comment_line,
            target: Some(SuppressionTarget::PolicyRule(PolicyRuleSuppression::new(
                pack, rule_id,
            ))),
        }
    }

    /// The bare issue kind if this suppression targets one.
    #[must_use]
    pub const fn issue_kind_target(&self) -> Option<IssueKind> {
        match &self.target {
            Some(SuppressionTarget::Issue(kind)) => Some(*kind),
            Some(SuppressionTarget::PolicyRule(_)) | None => None,
        }
    }

    /// The scoped policy target if this suppression targets one rule-pack rule.
    #[must_use]
    pub const fn policy_rule_target(&self) -> Option<&PolicyRuleSuppression> {
        match &self.target {
            Some(SuppressionTarget::PolicyRule(rule)) => Some(rule),
            Some(SuppressionTarget::Issue(_)) | None => None,
        }
    }

    /// Canonical token for this suppression, or `None` for blanket comments.
    #[must_use]
    pub fn target_token(&self) -> Option<String> {
        self.target.as_ref().map(SuppressionTarget::token)
    }

    /// Whether the comment applies to `line`.
    #[must_use]
    pub const fn applies_to_line(&self, line: u32) -> bool {
        self.line == 0 || self.line == line
    }

    /// Whether this suppression covers a regular issue kind on a line.
    ///
    /// Scoped policy-rule targets intentionally do not match this generic
    /// predicate. Policy detection uses [`Self::matches_policy_rule`] so the
    /// exact pack and rule id are available.
    #[must_use]
    pub fn matches_issue_kind(&self, line: u32, kind: IssueKind) -> bool {
        self.applies_to_line(line)
            && match &self.target {
                None => true,
                Some(SuppressionTarget::Issue(target_kind)) => *target_kind == kind,
                Some(SuppressionTarget::PolicyRule(_)) => false,
            }
    }

    /// Whether this suppression covers a policy finding on a line.
    #[must_use]
    pub fn matches_policy_rule(&self, line: u32, pack: &str, rule_id: &str) -> bool {
        self.applies_to_line(line)
            && match &self.target {
                None | Some(SuppressionTarget::Issue(IssueKind::PolicyViolation)) => true,
                Some(SuppressionTarget::Issue(_)) => false,
                Some(SuppressionTarget::PolicyRule(target)) => {
                    target.pack == pack && target.rule_id == rule_id
                }
            }
    }
}

/// A suppression token that did not parse to any known `IssueKind`.
///
/// Emitted alongside `Suppression` when a `// fallow-ignore-*` marker contains
/// a typo or an obsolete issue-kind name. The known tokens on the same marker
/// are recorded as normal `Suppression` entries; this struct preserves the
/// unknown token so the downstream `find_stale` pass can surface it as a
/// `StaleSuppression` finding with `kind_known: false`. Without this, the
/// entire suppression line would be discarded silently. See issue #449.
#[derive(Debug, Clone)]
pub struct UnknownSuppressionKind {
    /// 1-based line where the suppression comment itself appears.
    pub comment_line: u32,
    /// Whether the marker was `fallow-ignore-file` (`true`) or
    /// `fallow-ignore-next-line` (`false`).
    pub is_file_level: bool,
    /// The verbatim token from the marker that did not parse.
    pub token: String,
}

/// Canonical kebab-case names accepted by `IssueKind::parse`, including
/// documented plural aliases.
///
/// Used by `closest_known_kind_name` for Levenshtein "did you mean?" hints
/// when a suppression marker carries an unknown token. Keep in sync with the
/// `IssueKind::parse` match table above; the
/// `issue_kind_parse_covers_known_names` test asserts every entry round-trips.
pub const KNOWN_ISSUE_KIND_NAMES: &[&str] = &[
    "unused-file",
    "unused-export",
    "unused-type",
    "private-type-leak",
    "unused-dependency",
    "unused-dev-dependency",
    "unused-enum-member",
    "unused-class-member",
    "unresolved-import",
    "unlisted-dependency",
    "duplicate-export",
    "code-duplication",
    "circular-dependency",
    "circular-dependencies",
    "re-export-cycle",
    "re-export-cycles",
    "reexport-cycle",
    "reexport-cycles",
    "type-only-dependency",
    "test-only-dependency",
    "boundary-violation",
    "boundary-call-violation",
    "boundary-call-violations",
    "coverage-gaps",
    "feature-flag",
    "complexity",
    "stale-suppression",
    "unused-catalog-entry",
    "unused-catalog-entries",
    "empty-catalog-group",
    "empty-catalog-groups",
    "unresolved-catalog-reference",
    "unresolved-catalog-references",
    "unused-dependency-override",
    "unused-dependency-overrides",
    "misconfigured-dependency-override",
    "misconfigured-dependency-overrides",
    "security-client-server-leak",
    "security-sink",
    "policy-violation",
    "policy-violations",
];

/// CLI filter flags on `fallow dead-code` that scope output to a single
/// issue type.
///
/// Shared home so the agent capability manifest (`fallow schema` in
/// `crates/cli`), the MCP server's `issue_types` allowlist
/// (`ISSUE_TYPE_FLAGS` in `crates/mcp`), and the clap flag definitions stay
/// in sync: each crate carries a drift test asserting its own list against
/// this one.
pub const DEAD_CODE_FILTER_FLAGS: &[&str] = &[
    "--unused-files",
    "--unused-exports",
    "--unused-types",
    "--private-type-leaks",
    "--unused-deps",
    "--unused-enum-members",
    "--unused-class-members",
    "--unresolved-imports",
    "--unlisted-deps",
    "--duplicate-exports",
    "--circular-deps",
    "--re-export-cycles",
    "--boundary-violations",
    "--policy-violations",
    "--stale-suppressions",
    "--unused-catalog-entries",
    "--empty-catalog-groups",
    "--unresolved-catalog-references",
    "--unused-dependency-overrides",
    "--misconfigured-dependency-overrides",
];

/// Levenshtein edit distance between two ASCII-leaning strings.
///
/// Local duplicate of the config-crate helper (see
/// `crates/config/src/config/rules.rs::levenshtein`) so `fallow-types` can
/// compute "did you mean?" suggestions for unknown suppression tokens without
/// taking a dependency on `fallow-config`. Issue-kind names are short
/// (max ~33 chars) so allocation cost is negligible.
fn levenshtein(a: &str, b: &str) -> usize {
    let a_bytes = a.as_bytes();
    let b_bytes = b.as_bytes();
    let (a_len, b_len) = (a_bytes.len(), b_bytes.len());

    if a_len == 0 {
        return b_len;
    }
    if b_len == 0 {
        return a_len;
    }

    let mut prev: Vec<usize> = (0..=b_len).collect();
    let mut curr: Vec<usize> = vec![0; b_len + 1];

    for i in 1..=a_len {
        curr[0] = i;
        for j in 1..=b_len {
            let cost = usize::from(a_bytes[i - 1] != b_bytes[j - 1]);
            curr[j] = (prev[j] + 1).min(curr[j - 1] + 1).min(prev[j - 1] + cost);
        }
        std::mem::swap(&mut prev, &mut curr);
    }

    prev[b_len]
}

/// Find the closest known issue-kind name to `input` when it is plausibly a typo.
///
/// Returns the best match when the Levenshtein distance is at most 2 AND
/// the input is long enough that the match is not coincidental
/// (`input.len() / 2 > distance`). Returns `None` for completely novel
/// strings where a suggestion would be misleading.
#[must_use]
pub fn closest_known_kind_name(input: &str) -> Option<&'static str> {
    let input_lower = input.to_ascii_lowercase();
    let mut best: Option<(&'static str, usize)> = None;

    for &candidate in KNOWN_ISSUE_KIND_NAMES {
        let d = levenshtein(&input_lower, candidate);
        if best.is_none_or(|(_, b_dist)| d < b_dist) {
            best = Some((candidate, d));
        }
    }

    best.filter(|&(_, d)| d > 0 && d <= 2 && input_lower.len() / 2 > d)
        .map(|(name, _)| name)
}

const _: () = assert!(std::mem::size_of::<IssueKind>() == 1);

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn issue_kind_from_str_all_variants() {
        assert_eq!(IssueKind::parse("unused-file"), Some(IssueKind::UnusedFile));
        assert_eq!(
            IssueKind::parse("unused-export"),
            Some(IssueKind::UnusedExport)
        );
        assert_eq!(IssueKind::parse("unused-type"), Some(IssueKind::UnusedType));
        assert_eq!(
            IssueKind::parse("private-type-leak"),
            Some(IssueKind::PrivateTypeLeak)
        );
        assert_eq!(
            IssueKind::parse("unused-dependency"),
            Some(IssueKind::UnusedDependency)
        );
        assert_eq!(
            IssueKind::parse("unused-dev-dependency"),
            Some(IssueKind::UnusedDevDependency)
        );
        assert_eq!(
            IssueKind::parse("unused-enum-member"),
            Some(IssueKind::UnusedEnumMember)
        );
        assert_eq!(
            IssueKind::parse("unused-class-member"),
            Some(IssueKind::UnusedClassMember)
        );
        assert_eq!(
            IssueKind::parse("unresolved-import"),
            Some(IssueKind::UnresolvedImport)
        );
        assert_eq!(
            IssueKind::parse("unlisted-dependency"),
            Some(IssueKind::UnlistedDependency)
        );
        assert_eq!(
            IssueKind::parse("duplicate-export"),
            Some(IssueKind::DuplicateExport)
        );
        assert_eq!(
            IssueKind::parse("code-duplication"),
            Some(IssueKind::CodeDuplication)
        );
        assert_eq!(
            IssueKind::parse("circular-dependency"),
            Some(IssueKind::CircularDependency)
        );
        assert_eq!(
            IssueKind::parse("circular-dependencies"),
            Some(IssueKind::CircularDependency)
        );
        assert_eq!(
            IssueKind::parse("type-only-dependency"),
            Some(IssueKind::TypeOnlyDependency)
        );
        assert_eq!(
            IssueKind::parse("test-only-dependency"),
            Some(IssueKind::TestOnlyDependency)
        );
        assert_eq!(
            IssueKind::parse("boundary-violation"),
            Some(IssueKind::BoundaryViolation)
        );
        // The boundary family token also accepts the rule-id-shaped alias so
        // users who derive the token from the `boundary-call-violation` rule
        // id by analogy get a working suppression instead of a silent no-op.
        assert_eq!(
            IssueKind::parse("boundary-call-violation"),
            Some(IssueKind::BoundaryViolation)
        );
        assert_eq!(
            IssueKind::parse("boundary-call-violations"),
            Some(IssueKind::BoundaryViolation)
        );
        assert_eq!(
            IssueKind::parse("coverage-gaps"),
            Some(IssueKind::CoverageGaps)
        );
        assert_eq!(
            IssueKind::parse("feature-flag"),
            Some(IssueKind::FeatureFlag)
        );
        assert_eq!(IssueKind::parse("complexity"), Some(IssueKind::Complexity));
        assert_eq!(
            IssueKind::parse("stale-suppression"),
            Some(IssueKind::StaleSuppression)
        );
        assert_eq!(
            IssueKind::parse("unused-catalog-entry"),
            Some(IssueKind::PnpmCatalogEntry)
        );
        assert_eq!(
            IssueKind::parse("unused-catalog-entries"),
            Some(IssueKind::PnpmCatalogEntry)
        );
        assert_eq!(
            IssueKind::parse("empty-catalog-group"),
            Some(IssueKind::EmptyCatalogGroup)
        );
        assert_eq!(
            IssueKind::parse("empty-catalog-groups"),
            Some(IssueKind::EmptyCatalogGroup)
        );
        assert_eq!(
            IssueKind::parse("unresolved-catalog-reference"),
            Some(IssueKind::UnresolvedCatalogReference)
        );
        assert_eq!(
            IssueKind::parse("unresolved-catalog-references"),
            Some(IssueKind::UnresolvedCatalogReference)
        );
        assert_eq!(
            IssueKind::parse("unused-dependency-override"),
            Some(IssueKind::UnusedDependencyOverride)
        );
        assert_eq!(
            IssueKind::parse("unused-dependency-overrides"),
            Some(IssueKind::UnusedDependencyOverride)
        );
        assert_eq!(
            IssueKind::parse("misconfigured-dependency-override"),
            Some(IssueKind::MisconfiguredDependencyOverride)
        );
        assert_eq!(
            IssueKind::parse("misconfigured-dependency-overrides"),
            Some(IssueKind::MisconfiguredDependencyOverride)
        );
        assert_eq!(
            IssueKind::parse("security-client-server-leak"),
            Some(IssueKind::SecurityClientServerLeak)
        );
        assert_eq!(
            IssueKind::parse("security-sink"),
            Some(IssueKind::SecuritySink)
        );
        assert_eq!(
            IssueKind::parse("policy-violation"),
            Some(IssueKind::PolicyViolation)
        );
        assert_eq!(
            IssueKind::parse("policy-violations"),
            Some(IssueKind::PolicyViolation)
        );
    }

    #[test]
    fn issue_kind_from_str_unknown() {
        assert_eq!(IssueKind::parse("foo"), None);
        assert_eq!(IssueKind::parse(""), None);
    }

    #[test]
    fn issue_kind_from_str_near_misses() {
        assert_eq!(IssueKind::parse("Unused-File"), None);
        assert_eq!(IssueKind::parse("UNUSED-EXPORT"), None);
        assert_eq!(IssueKind::parse("unused_file"), None);
        assert_eq!(IssueKind::parse("unused-files"), None);
    }

    #[test]
    fn discriminant_out_of_range() {
        assert_eq!(IssueKind::from_discriminant(0), None);
        assert_eq!(
            IssueKind::from_discriminant(29),
            Some(IssueKind::PolicyViolation)
        );
        assert_eq!(IssueKind::from_discriminant(30), None);
        assert_eq!(IssueKind::from_discriminant(u8::MAX), None);
    }

    #[test]
    fn discriminant_roundtrip() {
        for kind in [
            IssueKind::UnusedFile,
            IssueKind::UnusedExport,
            IssueKind::UnusedType,
            IssueKind::PrivateTypeLeak,
            IssueKind::UnusedDependency,
            IssueKind::UnusedDevDependency,
            IssueKind::UnusedEnumMember,
            IssueKind::UnusedClassMember,
            IssueKind::UnresolvedImport,
            IssueKind::UnlistedDependency,
            IssueKind::DuplicateExport,
            IssueKind::CodeDuplication,
            IssueKind::CircularDependency,
            IssueKind::ReExportCycle,
            IssueKind::TypeOnlyDependency,
            IssueKind::TestOnlyDependency,
            IssueKind::BoundaryViolation,
            IssueKind::CoverageGaps,
            IssueKind::FeatureFlag,
            IssueKind::Complexity,
            IssueKind::StaleSuppression,
            IssueKind::PnpmCatalogEntry,
            IssueKind::EmptyCatalogGroup,
            IssueKind::UnresolvedCatalogReference,
            IssueKind::UnusedDependencyOverride,
            IssueKind::MisconfiguredDependencyOverride,
            IssueKind::SecurityClientServerLeak,
            IssueKind::SecuritySink,
            IssueKind::PolicyViolation,
        ] {
            assert_eq!(
                IssueKind::from_discriminant(kind.to_discriminant()),
                Some(kind)
            );
        }
        assert_eq!(IssueKind::from_discriminant(0), None);
        assert_eq!(IssueKind::from_discriminant(30), None);
    }

    #[test]
    fn discriminant_values_are_unique() {
        let all_kinds = [
            IssueKind::UnusedFile,
            IssueKind::UnusedExport,
            IssueKind::UnusedType,
            IssueKind::PrivateTypeLeak,
            IssueKind::UnusedDependency,
            IssueKind::UnusedDevDependency,
            IssueKind::UnusedEnumMember,
            IssueKind::UnusedClassMember,
            IssueKind::UnresolvedImport,
            IssueKind::UnlistedDependency,
            IssueKind::DuplicateExport,
            IssueKind::CodeDuplication,
            IssueKind::CircularDependency,
            IssueKind::ReExportCycle,
            IssueKind::TypeOnlyDependency,
            IssueKind::TestOnlyDependency,
            IssueKind::BoundaryViolation,
            IssueKind::CoverageGaps,
            IssueKind::FeatureFlag,
            IssueKind::Complexity,
            IssueKind::StaleSuppression,
            IssueKind::PnpmCatalogEntry,
            IssueKind::EmptyCatalogGroup,
            IssueKind::UnresolvedCatalogReference,
            IssueKind::UnusedDependencyOverride,
            IssueKind::MisconfiguredDependencyOverride,
            IssueKind::SecurityClientServerLeak,
            IssueKind::SecuritySink,
            IssueKind::PolicyViolation,
        ];
        let discriminants: Vec<u8> = all_kinds.iter().map(|k| k.to_discriminant()).collect();
        let mut sorted = discriminants.clone();
        sorted.sort_unstable();
        sorted.dedup();
        assert_eq!(
            discriminants.len(),
            sorted.len(),
            "discriminant values must be unique"
        );
    }

    #[test]
    fn discriminant_starts_at_one() {
        assert_eq!(IssueKind::UnusedFile.to_discriminant(), 1);
    }

    #[test]
    fn suppression_line_zero_is_file_wide() {
        let s = Suppression::all(0, 1);
        assert_eq!(s.line, 0);
        assert!(s.issue_kind_target().is_none());
    }

    #[test]
    fn suppression_with_specific_kind_and_line() {
        let s = Suppression::issue(42, 41, IssueKind::UnusedExport);
        assert_eq!(s.line, 42);
        assert_eq!(s.comment_line, 41);
        assert_eq!(s.issue_kind_target(), Some(IssueKind::UnusedExport));
    }

    #[test]
    fn parses_scoped_policy_suppression_token() {
        let target =
            parse_policy_rule_suppression_token("policy-violation:team-policy/no-child-process")
                .expect("scoped token should parse");
        assert_eq!(target.pack, "team-policy");
        assert_eq!(target.rule_id, "no-child-process");
        assert_eq!(
            target.token(),
            "policy-violation:team-policy/no-child-process"
        );
    }

    #[test]
    fn rejects_malformed_scoped_policy_suppression_tokens() {
        for token in [
            "policy-violation:",
            "policy-violation:team-policy",
            "policy-violation:/no-child-process",
            "policy-violation:team-policy/",
            "policy-violation:team-policy/no/child-process",
            "policy-violation:team policy/no-child-process",
            "policy-violation:team-policy/no:child-process",
        ] {
            assert!(
                parse_policy_rule_suppression_token(token).is_none(),
                "{token} should be rejected"
            );
        }
    }

    #[test]
    fn scoped_policy_suppression_matches_exact_policy_rule_only() {
        let suppression = Suppression::policy_rule(7, 6, "team-policy", "no-child-process");
        assert!(suppression.matches_policy_rule(7, "team-policy", "no-child-process"));
        assert!(!suppression.matches_policy_rule(7, "team-policy", "no-fs"));
        assert!(!suppression.matches_policy_rule(8, "team-policy", "no-child-process"));
        assert!(!suppression.matches_issue_kind(7, IssueKind::PolicyViolation));
    }

    #[test]
    fn known_issue_kind_names_parses_each_entry() {
        for &name in KNOWN_ISSUE_KIND_NAMES {
            assert!(
                IssueKind::parse(name).is_some(),
                "KNOWN_ISSUE_KIND_NAMES contains '{name}' but IssueKind::parse rejects it"
            );
        }
    }

    #[test]
    fn closest_known_kind_name_finds_near_misses() {
        assert_eq!(
            closest_known_kind_name("unused-exports"),
            Some("unused-export")
        );
        assert_eq!(closest_known_kind_name("unused-files"), Some("unused-file"));
        assert_eq!(closest_known_kind_name("complxity"), Some("complexity"));
    }

    #[test]
    fn closest_known_kind_name_rejects_novel_strings() {
        assert_eq!(closest_known_kind_name("xyzzy"), None);
        assert_eq!(closest_known_kind_name("foo"), None);
        assert_eq!(closest_known_kind_name(""), None);
    }

    #[test]
    fn closest_known_kind_name_skips_exact_match() {
        assert_eq!(closest_known_kind_name("unused-export"), None);
    }
}