harn_parser/diagnostic_codes/
repairs.rs

1//! Repair vocabulary attached to a diagnostic code.
2//!
3//! A diagnostic says what is wrong; a repair says what an agent or editor may
4//! do about it and how far that action is allowed to reach. The safety ladder
5//! here is a contract surface — `harn fix --safety <class>` and IDE auto-apply
6//! ceilings both compare against it — so the wire strings are as stable as the
7//! codes themselves.
8//!
9//! Split out of `diagnostic_codes.rs` (#6126), which had reached its
10//! source-length ceiling and could not accept another code. The registry keeps
11//! the codes; this module keeps everything that answers "and what do I do".
12
13use std::{fmt, str::FromStr};
14
15use super::Code;
16
17/// Autonomy ceiling of a proposed repair.
18///
19/// Agents and IDEs use this class to auto-apply, suggest, or escalate a fix. Variants
20/// are ordered from least to most disruptive — call sites can compare
21/// with `<=` to enforce a configured ceiling like
22/// `"apply anything up to behavior-preserving"`.
23///
24/// The wire-format strings (`format-only`, `behavior-preserving`, …) are
25/// the contract surface; renaming a variant string is a breaking change.
26#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
27pub enum RepairSafety {
28    /// Whitespace, trivia, or canonical layout only. No code structure
29    /// changes; safe to auto-apply.
30    FormatOnly,
31    /// Intended not to change observable runtime behavior (e.g. delete an
32    /// unreachable branch, drop a redundant cast).
33    BehaviorPreserving,
34    /// Confined to the current local scope or file. Runtime behavior may
35    /// change, but the blast radius does not cross a declaration boundary
36    /// or a public surface.
37    ScopeLocal,
38    /// Touches a signature, export, or call-site surface that other files
39    /// or external consumers can observe.
40    SurfaceChanging,
41    /// Required capabilities or sandbox profile may change as a result of
42    /// applying the repair (e.g. swapping `provider: "openai"` for a
43    /// capability flag widens the routing surface).
44    CapabilityChanging,
45    /// Planning hint only — agents should propose, never auto-apply.
46    /// Aligned with the `AutonomyTier::Suggest`/`ActWithApproval` rungs
47    /// in `trust_graph.rs`.
48    NeedsHuman,
49}
50
51impl RepairSafety {
52    pub const ALL: &'static [RepairSafety] = &[
53        RepairSafety::FormatOnly,
54        RepairSafety::BehaviorPreserving,
55        RepairSafety::ScopeLocal,
56        RepairSafety::SurfaceChanging,
57        RepairSafety::CapabilityChanging,
58        RepairSafety::NeedsHuman,
59    ];
60
61    /// Stable wire-format string. The contract surface — do not rename
62    /// without coordinating with `harn fix --safety <…>` callers and
63    /// downstream LSP/IDE clients.
64    pub const fn as_str(self) -> &'static str {
65        match self {
66            RepairSafety::FormatOnly => "format-only",
67            RepairSafety::BehaviorPreserving => "behavior-preserving",
68            RepairSafety::ScopeLocal => "scope-local",
69            RepairSafety::SurfaceChanging => "surface-changing",
70            RepairSafety::CapabilityChanging => "capability-changing",
71            RepairSafety::NeedsHuman => "needs-human",
72        }
73    }
74
75    /// True when `self` sits at or below `ceiling`. Used by
76    /// `harn fix --apply --safety <ceiling>` and IDE auto-apply policies
77    /// to decide whether a repair clears the configured autonomy bar.
78    pub const fn is_at_most(self, ceiling: RepairSafety) -> bool {
79        (self as u8) <= (ceiling as u8)
80    }
81
82    /// Whether an editor or `harn lint --fix` may apply this repair without
83    /// an explicit safety opt-in.
84    pub const fn is_machine_applicable(self) -> bool {
85        self.is_at_most(RepairSafety::BehaviorPreserving)
86    }
87}
88
89impl fmt::Display for RepairSafety {
90    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
91        f.write_str(self.as_str())
92    }
93}
94
95/// Error returned when parsing an unknown repair-safety string.
96#[derive(Debug, Clone, Copy, PartialEq, Eq)]
97pub struct ParseRepairSafetyError;
98
99impl fmt::Display for ParseRepairSafetyError {
100    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
101        f.write_str("unknown Harn repair-safety class")
102    }
103}
104
105impl std::error::Error for ParseRepairSafetyError {}
106
107impl FromStr for RepairSafety {
108    type Err = ParseRepairSafetyError;
109
110    fn from_str(value: &str) -> Result<Self, Self::Err> {
111        RepairSafety::ALL
112            .iter()
113            .copied()
114            .find(|safety| safety.as_str() == value)
115            .ok_or(ParseRepairSafetyError)
116    }
117}
118
119/// Namespaced kebab-case repair identifier (e.g. `imports/fix-path`).
120///
121/// Wraps a `Cow` so registry-driven values reuse a `'static` literal and
122/// per-site overrides can still attach an owned string. The wire-format
123/// string is the contract surface — never normalize or reformat on read.
124#[derive(Debug, Clone, PartialEq, Eq, Hash)]
125pub struct RepairId(std::borrow::Cow<'static, str>);
126
127impl RepairId {
128    pub const fn from_static(s: &'static str) -> Self {
129        RepairId(std::borrow::Cow::Borrowed(s))
130    }
131
132    pub fn from_owned(s: String) -> Self {
133        RepairId(std::borrow::Cow::Owned(s))
134    }
135
136    pub fn as_str(&self) -> &str {
137        &self.0
138    }
139}
140
141impl fmt::Display for RepairId {
142    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
143        f.write_str(&self.0)
144    }
145}
146
147/// A structured repair proposal attached to a diagnostic.
148///
149/// `id` and `summary` are agent-readable metadata; `safety` is the
150/// dispatch dimension that decides whether the repair clears an
151/// autonomy ceiling. The concrete edits, when known statically, live on
152/// the diagnostic's `fix: Option<Vec<FixEdit>>`; this `Repair` is the
153/// classifier above those edits, not a replacement for them.
154#[derive(Debug, Clone)]
155pub struct Repair {
156    pub id: RepairId,
157    pub summary: String,
158    pub safety: RepairSafety,
159}
160
161impl Repair {
162    pub fn from_template(template: &RepairTemplate) -> Self {
163        Repair {
164            id: RepairId::from_static(template.id),
165            summary: template.summary.to_string(),
166            safety: template.safety,
167        }
168    }
169}
170
171/// Static-lifetime repair template bound to a diagnostic code.
172///
173/// Stored in the registry alongside `Code`. Construction sites can
174/// materialize a `Repair` via [`Repair::from_template`] or override
175/// `summary` for instance-specific detail by building a `Repair`
176/// directly.
177#[derive(Debug, Clone, Copy)]
178pub struct RepairTemplate {
179    pub id: &'static str,
180    pub summary: &'static str,
181    pub safety: RepairSafety,
182}
183
184impl Code {
185    /// Look up the default repair template attached to this diagnostic
186    /// code, or `None` if no actionable fix shape is registered.
187    pub const fn repair_template(self) -> Option<&'static RepairTemplate> {
188        match self {
189            // --- TYP: type mismatches & coercions -------------------------
190            Code::TypeMismatch
191            | Code::ReturnTypeMismatch
192            | Code::AssignmentTypeMismatch
193            | Code::ArgumentTypeMismatch
194            | Code::VariableTypeMismatch
195            | Code::ClosureReturnTypeMismatch
196            | Code::FieldTypeMismatch
197            | Code::MethodTypeMismatch
198            | Code::InvalidIndexType => Some(&REPAIR_INSERT_EXPLICIT_CONVERSION),
199            Code::StringInterpolationRewrite => Some(&REPAIR_REWRITE_STRING_INTERPOLATION),
200            Code::UnknownTypeName => Some(&REPAIR_IMPORTS_FIX_PATH),
201            Code::ImplicitAnyParameter => Some(&REPAIR_TYPES_ANNOTATE_PARAMETER),
202            Code::InvalidCast => Some(&REPAIR_CASTS_REMOVE_UNCHECKED),
203
204            // --- NAM / IMP: imports & names -------------------------------
205            Code::UndefinedVariable
206            | Code::UndefinedFunction
207            | Code::UnknownField
208            | Code::UnknownMethod
209            | Code::UnknownBuiltin
210            | Code::UnknownDeclaration => Some(&REPAIR_BINDINGS_RENAME_TO_CLOSEST),
211            Code::InvalidMainSignature => Some(&REPAIR_BINDINGS_THREAD_HARNESS_NEEDS_PARAM),
212            Code::DeprecatedFunction => Some(&REPAIR_STDLIB_MIGRATE_RENAMED),
213            Code::ModuleImportUnresolved | Code::ImportResolutionFailed => {
214                Some(&REPAIR_IMPORTS_FIX_PATH)
215            }
216            Code::ModuleImportUnused => Some(&REPAIR_IMPORTS_REMOVE_UNUSED),
217            Code::ModuleImportOrder => Some(&REPAIR_IMPORTS_REORDER),
218
219            // --- CAP / RCV: capabilities & error recovery -----------------
220            Code::CapabilityResultUnchecked => Some(&REPAIR_ERRORS_CHECK_OR_RESCUE),
221            Code::CapabilityBindingInvalid => Some(&REPAIR_MANUAL_REVIEW_CAPABILITY),
222            Code::EffectInheritanceViolation => Some(&REPAIR_POLICY_NARROW_CHILD_EFFECTS),
223            Code::RescueOutsideFunction | Code::TryOutsideFunction => {
224                Some(&REPAIR_ERRORS_WRAP_IN_FN)
225            }
226
227            // --- LLM / PRM: model + prompt contract -----------------------
228            Code::LlmSchemaMissing => Some(&REPAIR_LLM_ADD_SCHEMA),
229            Code::LlmProviderIdentityBranch | Code::PromptProviderIdentityBranch => {
230                Some(&REPAIR_LLM_USE_CAPABILITY_FLAG)
231            }
232            Code::PromptInjectionRisk => Some(&REPAIR_PROMPTS_ESCAPE_INJECTION),
233            Code::PromptToolSurfaceUnknown | Code::PromptToolSurfaceDeferredReference => {
234                Some(&REPAIR_PROMPTS_ADD_TOOL_TO_SURFACE)
235            }
236            Code::PromptVariantExplosion => Some(&REPAIR_MANUAL_NEEDS_HUMAN),
237
238            // --- STD: stdlib usage ----------------------------------------
239            Code::DeprecatedStdlibSymbol => Some(&REPAIR_STDLIB_MIGRATE_RENAMED),
240            Code::LintMissingStdlibMetadata => Some(&REPAIR_DOC_ADD_STDLIB_METADATA),
241
242            // --- OWN: ownership & mutability ------------------------------
243            Code::ImmutableAssignment => Some(&REPAIR_BINDINGS_MAKE_MUTABLE),
244            Code::MutableNeverReassigned => Some(&REPAIR_BINDINGS_MAKE_IMMUTABLE),
245
246            // --- MAT: match exhaustiveness --------------------------------
247            Code::NonExhaustiveMatch => Some(&REPAIR_MATCH_ADD_MISSING_ARMS),
248            Code::DuplicateMatchArm => Some(&REPAIR_MATCH_REMOVE_DUPLICATE_ARM),
249
250            // --- ORC: orchestration ---------------------------------------
251            Code::UnreachableCode => Some(&REPAIR_DEAD_CODE_REMOVE),
252
253            // --- FMT: formatter -------------------------------------------
254            Code::FormatterWouldReformat | Code::FormatterTrailingComma => {
255                Some(&REPAIR_FORMAT_REFORMAT)
256            }
257
258            // --- LNT: lints with structured fixes -------------------------
259            Code::LintUnusedVariable
260            | Code::LintUnusedPatternBinding
261            | Code::LintUnusedParameter => Some(&REPAIR_BINDINGS_RENAME_UNUSED),
262            Code::LintUnusedPipelineInput => Some(&REPAIR_BINDINGS_REMOVE_UNUSED_PIPELINE_INPUT),
263            Code::LintCapabilityParameterName => Some(&REPAIR_BINDINGS_NAME_CAPABILITY_PARAMETER),
264            Code::LintUnusedImport => Some(&REPAIR_IMPORTS_REMOVE_UNUSED),
265            Code::LintUnusedFunction | Code::LintUnusedType => {
266                Some(&REPAIR_DECLARATIONS_REMOVE_UNUSED)
267            }
268            Code::LintMutableNeverReassigned => Some(&REPAIR_BINDINGS_MAKE_IMMUTABLE),
269            Code::LintImportOrder => Some(&REPAIR_IMPORTS_REORDER),
270            Code::LintBlankLineBetweenItems
271            | Code::LintTrailingComma
272            | Code::LintUnnecessaryParentheses
273            | Code::LintRequireFileHeader => Some(&REPAIR_FORMAT_REFORMAT),
274            Code::LintLegacyDocComment => Some(&REPAIR_DOC_COMMENT_MIGRATE),
275            Code::LintEmptyBlock => Some(&REPAIR_BLOCK_REMOVE_EMPTY),
276            Code::LintUnnecessaryElseReturn | Code::LintLetThenReturn => {
277                Some(&REPAIR_CONTROL_FLOW_FLATTEN)
278            }
279            Code::LintNilCoalesceNoop
280            | Code::LintNilCoalesceSelfFallback
281            | Code::LintRedundantNilTernary
282            | Code::LintUnnecessarySafeNavigation
283            | Code::LintUnnecessaryNonNullAssert
284            | Code::LintPreferOptionalShorthand
285            | Code::LintComparisonToBool
286            | Code::LintPointlessComparison
287            | Code::LintConstantLogicalOperand => Some(&REPAIR_EXPRESSION_SIMPLIFY),
288            Code::LintPreferPick => Some(&REPAIR_RECORDS_PICK_FIELDS),
289            Code::LintUnnecessaryCast => Some(&REPAIR_CASTS_REMOVE_REDUNDANT),
290            Code::LintRedundantClone => Some(&REPAIR_CLONE_REMOVE_REDUNDANT),
291            Code::LintEagerCollectionConversion => Some(&REPAIR_COLLECTION_PREFER_LAZY),
292            Code::LintDeadCodeAfterReturn => Some(&REPAIR_DEAD_CODE_REMOVE),
293            Code::LintRenamedStdlibSymbol => Some(&REPAIR_STDLIB_MIGRATE_RENAMED),
294            Code::LintAmbientClockBuiltin => Some(&REPAIR_BINDINGS_THREAD_HARNESS_CLOCK),
295            Code::LintAmbientFsBuiltin => Some(&REPAIR_BINDINGS_THREAD_HARNESS_FS),
296            Code::LintAmbientEnvBuiltin => Some(&REPAIR_BINDINGS_THREAD_HARNESS_ENV),
297            Code::LintAmbientRandomBuiltin => Some(&REPAIR_BINDINGS_THREAD_HARNESS_RANDOM),
298            Code::LintAmbientNetBuiltin => Some(&REPAIR_BINDINGS_THREAD_HARNESS_NET),
299            Code::LintAmbientStdioBuiltin => Some(&REPAIR_BINDINGS_THREAD_HARNESS),
300            Code::LintAmbientHarnessMethod => Some(&REPAIR_BINDINGS_THREAD_HARNESS_METHOD),
301            Code::LintBroadHarnessParameter => Some(&REPAIR_BINDINGS_ATTENUATE_HARNESS),
302            Code::LintRemovedLlmOptions => Some(&REPAIR_LLM_MIGRATE_REMOVED_OPTION),
303            Code::LintTemplateProviderIdentityBranch => Some(&REPAIR_LLM_USE_CAPABILITY_FLAG),
304            Code::LintPromptInjectionRisk => Some(&REPAIR_PROMPTS_ESCAPE_INJECTION),
305            Code::LintShadowVariable => Some(&REPAIR_BINDINGS_RENAME_SHADOW),
306            Code::LintNamingConvention => Some(&REPAIR_STYLE_RENAME_TO_CONVENTION),
307            Code::LintUnhandledApprovalResult => Some(&REPAIR_ERRORS_CHECK_OR_RESCUE),
308            Code::LintMissingHarndoc => Some(&REPAIR_DOC_ADD_HARNDOC),
309            Code::LintDuplicateMatchArm => Some(&REPAIR_MATCH_REMOVE_DUPLICATE_ARM),
310            // HARN-LNT-029 is the lint face of the boundary-validation rule, so
311            // its repair has to validate. HARN-LNT-060 below is a different
312            // complaint — an inline options dict bypassing the typed option
313            // constructors — where naming the shape is the whole fix and no
314            // untrusted payload is involved.
315            Code::LintUntypedDictAccess => Some(&REPAIR_TYPES_VALIDATE_BOUNDARY_VALUE),
316            Code::LintUnnormalizedOptions => Some(&REPAIR_TYPES_ADD_SHAPE_ANNOTATION),
317            Code::LintMcpToolAnnotations => Some(&REPAIR_MANUAL_NEEDS_HUMAN),
318            Code::LintTemplateVariantExplosion | Code::LintLongRunningWithoutCleanup => {
319                Some(&REPAIR_MANUAL_NEEDS_HUMAN)
320            }
321
322            // Everything else: no statically known repair shape. Agents
323            // should treat these as "diagnose only" until a repair is
324            // registered.
325            _ => None,
326        }
327    }
328}
329
330// Repair-id catalog. Each `RepairTemplate` carries a kebab-case
331// namespaced id (`<namespace>/<verb-noun>`), a one-line summary written
332// in the imperative voice, and a `RepairSafety` class.
333//
334// Conventions:
335//   - Namespaces stay short: `bindings/`, `imports/`, `errors/`, `casts/`,
336//     `format/`, `llm/`, `prompts/`, `match/`, `stdlib/`, `lint/`,
337//     `doc/`, `style/`, `types/`, `manual/`.
338//   - Summary starts with a verb ("Replace…", "Remove…", "Insert…").
339//   - Safety must be the most permissive class that is still always true
340//     for every site this template attaches to. When unsure, pick the
341//     stricter class — agents tighten too-loose policies later, never
342//     too-tight ones.
343
344const REPAIR_INSERT_EXPLICIT_CONVERSION: RepairTemplate = RepairTemplate {
345    id: "casts/insert-explicit-conversion",
346    summary: "Insert an explicit conversion or correct the operand type",
347    safety: RepairSafety::ScopeLocal,
348};
349
350const REPAIR_REWRITE_STRING_INTERPOLATION: RepairTemplate = RepairTemplate {
351    id: "style/string-interpolation",
352    summary: "Rewrite string concatenation as an interpolation literal",
353    safety: RepairSafety::BehaviorPreserving,
354};
355
356const REPAIR_CASTS_REMOVE_UNCHECKED: RepairTemplate = RepairTemplate {
357    id: "casts/remove-unchecked",
358    summary: "Remove the unchecked cast or guard it with a type test",
359    safety: RepairSafety::ScopeLocal,
360};
361
362const REPAIR_CASTS_REMOVE_REDUNDANT: RepairTemplate = RepairTemplate {
363    id: "casts/remove-redundant",
364    summary: "Remove the redundant cast",
365    safety: RepairSafety::BehaviorPreserving,
366};
367
368const REPAIR_BINDINGS_RENAME_TO_CLOSEST: RepairTemplate = RepairTemplate {
369    id: "bindings/rename-to-closest",
370    summary: "Rename to the closest in-scope identifier",
371    safety: RepairSafety::ScopeLocal,
372};
373
374const REPAIR_BINDINGS_MAKE_MUTABLE: RepairTemplate = RepairTemplate {
375    id: "bindings/make-mutable",
376    summary: "Declare the binding with `let` so it can be reassigned",
377    safety: RepairSafety::ScopeLocal,
378};
379
380const REPAIR_BINDINGS_MAKE_IMMUTABLE: RepairTemplate = RepairTemplate {
381    id: "bindings/make-immutable",
382    summary: "Declare the never-reassigned binding with `const` instead of `let`",
383    safety: RepairSafety::BehaviorPreserving,
384};
385
386const REPAIR_BINDINGS_RENAME_UNUSED: RepairTemplate = RepairTemplate {
387    id: "bindings/rename-unused",
388    summary: "Mark an unused binding without changing callable arity",
389    safety: RepairSafety::BehaviorPreserving,
390};
391
392const REPAIR_BINDINGS_REMOVE_UNUSED_PIPELINE_INPUT: RepairTemplate = RepairTemplate {
393    id: "bindings/remove-unused-pipeline-input",
394    summary: "Remove an explicitly unused test pipeline input",
395    safety: RepairSafety::SurfaceChanging,
396};
397
398const REPAIR_BINDINGS_NAME_CAPABILITY_PARAMETER: RepairTemplate = RepairTemplate {
399    id: "bindings/name-capability-parameter",
400    summary: "Rename the capability parameter and its references after the capability it carries",
401    safety: RepairSafety::SurfaceChanging,
402};
403
404const REPAIR_BINDINGS_RENAME_SHADOW: RepairTemplate = RepairTemplate {
405    id: "bindings/rename-shadow",
406    summary: "Rename the shadowing binding to a distinct name",
407    safety: RepairSafety::ScopeLocal,
408};
409
410const REPAIR_BINDINGS_THREAD_HARNESS: RepairTemplate = RepairTemplate {
411    id: "bindings/thread-harness",
412    summary: "Thread the existing `harness` binding through local helper calls and replace the ambient stdio builtin with `harness.stdio.*`",
413    safety: RepairSafety::ScopeLocal,
414};
415
416const REPAIR_BINDINGS_THREAD_HARNESS_NEEDS_PARAM: RepairTemplate = RepairTemplate {
417    id: "bindings/thread-harness-needs-param",
418    summary: "Add a `harness: Harness` parameter where the stdio capability handle is required and update local callers",
419    safety: RepairSafety::SurfaceChanging,
420};
421
422const REPAIR_BINDINGS_THREAD_HARNESS_METHOD: RepairTemplate = RepairTemplate {
423    id: "bindings/thread-harness-method",
424    summary: "Replace the ambient runtime builtin with its typed `harness.*` method and thread authority through local callers",
425    safety: RepairSafety::ScopeLocal,
426};
427
428const REPAIR_BINDINGS_THREAD_HARNESS_CLOCK: RepairTemplate = RepairTemplate {
429    id: "bindings/thread-harness-clock",
430    summary: "Replace the ambient clock builtin with the corresponding `harness.clock.*` method",
431    safety: RepairSafety::ScopeLocal,
432};
433
434const REPAIR_BINDINGS_THREAD_HARNESS_FS: RepairTemplate = RepairTemplate {
435    id: "bindings/thread-harness-fs",
436    summary: "Replace the ambient fs builtin with the corresponding `harness.fs.*` method",
437    safety: RepairSafety::ScopeLocal,
438};
439
440const REPAIR_BINDINGS_THREAD_HARNESS_ENV: RepairTemplate = RepairTemplate {
441    id: "bindings/thread-harness-env",
442    summary: "Replace the ambient env builtin with the corresponding `harness.env.*` method",
443    safety: RepairSafety::ScopeLocal,
444};
445
446const REPAIR_BINDINGS_THREAD_HARNESS_RANDOM: RepairTemplate = RepairTemplate {
447    id: "bindings/thread-harness-random",
448    summary: "Replace the ambient random builtin with the corresponding `harness.random.*` method",
449    safety: RepairSafety::ScopeLocal,
450};
451
452const REPAIR_BINDINGS_THREAD_HARNESS_NET: RepairTemplate = RepairTemplate {
453    id: "bindings/thread-harness-net",
454    summary: "Replace the ambient net builtin with the corresponding `harness.net.*` method",
455    safety: RepairSafety::ScopeLocal,
456};
457
458const REPAIR_DECLARATIONS_REMOVE_UNUSED: RepairTemplate = RepairTemplate {
459    id: "declarations/remove-unused",
460    summary: "Remove the unused declaration",
461    safety: RepairSafety::SurfaceChanging,
462};
463
464const REPAIR_IMPORTS_FIX_PATH: RepairTemplate = RepairTemplate {
465    id: "imports/fix-path",
466    summary: "Replace the import path with a resolvable target",
467    safety: RepairSafety::ScopeLocal,
468};
469
470const REPAIR_IMPORTS_REMOVE_UNUSED: RepairTemplate = RepairTemplate {
471    id: "imports/remove-unused",
472    summary: "Remove the unused import",
473    safety: RepairSafety::BehaviorPreserving,
474};
475
476const REPAIR_IMPORTS_REORDER: RepairTemplate = RepairTemplate {
477    id: "imports/reorder",
478    summary: "Reorder imports into canonical grouping",
479    safety: RepairSafety::FormatOnly,
480};
481
482const REPAIR_ERRORS_CHECK_OR_RESCUE: RepairTemplate = RepairTemplate {
483    id: "errors/check-or-rescue",
484    summary: "Check the result or wrap the call in a `rescue` block",
485    safety: RepairSafety::ScopeLocal,
486};
487
488const REPAIR_ERRORS_WRAP_IN_FN: RepairTemplate = RepairTemplate {
489    id: "errors/wrap-in-fn",
490    summary: "Move the construct inside a function body",
491    safety: RepairSafety::SurfaceChanging,
492};
493
494const REPAIR_MATCH_ADD_MISSING_ARMS: RepairTemplate = RepairTemplate {
495    id: "match/add-missing-arms",
496    summary: "Add arms covering the missing variants",
497    safety: RepairSafety::ScopeLocal,
498};
499
500const REPAIR_MATCH_REMOVE_DUPLICATE_ARM: RepairTemplate = RepairTemplate {
501    id: "match/remove-duplicate-arm",
502    summary: "Remove the duplicated match arm",
503    safety: RepairSafety::BehaviorPreserving,
504};
505
506const REPAIR_FORMAT_REFORMAT: RepairTemplate = RepairTemplate {
507    id: "format/reformat",
508    summary: "Apply canonical formatting",
509    safety: RepairSafety::FormatOnly,
510};
511
512const REPAIR_DOC_COMMENT_MIGRATE: RepairTemplate = RepairTemplate {
513    id: "doc/migrate-comment-style",
514    summary: "Migrate the legacy comment to canonical doc syntax",
515    safety: RepairSafety::FormatOnly,
516};
517
518const REPAIR_DOC_ADD_HARNDOC: RepairTemplate = RepairTemplate {
519    id: "doc/add-harndoc",
520    summary: "Add a `///` doc comment describing this declaration",
521    safety: RepairSafety::BehaviorPreserving,
522};
523
524const REPAIR_DOC_ADD_STDLIB_METADATA: RepairTemplate = RepairTemplate {
525    id: "doc/add-stdlib-metadata",
526    summary: "Add `@effects` and `@errors` fields to the stdlib function's doc block",
527    safety: RepairSafety::BehaviorPreserving,
528};
529
530const REPAIR_BLOCK_REMOVE_EMPTY: RepairTemplate = RepairTemplate {
531    id: "blocks/remove-empty",
532    summary: "Remove the empty block or fill in an explicit body",
533    safety: RepairSafety::ScopeLocal,
534};
535
536const REPAIR_CONTROL_FLOW_FLATTEN: RepairTemplate = RepairTemplate {
537    id: "control-flow/flatten",
538    summary: "Flatten the unnecessary control flow construct",
539    safety: RepairSafety::BehaviorPreserving,
540};
541
542const REPAIR_EXPRESSION_SIMPLIFY: RepairTemplate = RepairTemplate {
543    id: "expressions/simplify",
544    summary: "Simplify the expression to its canonical form",
545    safety: RepairSafety::BehaviorPreserving,
546};
547
548const REPAIR_RECORDS_PICK_FIELDS: RepairTemplate = RepairTemplate {
549    id: "records/pick-fields",
550    summary: "Replace the field-by-field record copy with `pick`",
551    safety: RepairSafety::BehaviorPreserving,
552};
553
554const REPAIR_CLONE_REMOVE_REDUNDANT: RepairTemplate = RepairTemplate {
555    id: "clones/remove-redundant",
556    summary: "Remove the redundant clone",
557    safety: RepairSafety::BehaviorPreserving,
558};
559
560const REPAIR_COLLECTION_PREFER_LAZY: RepairTemplate = RepairTemplate {
561    id: "collections/prefer-lazy",
562    summary: "Replace the eager collection step with a lazy variant",
563    safety: RepairSafety::ScopeLocal,
564};
565
566const REPAIR_DEAD_CODE_REMOVE: RepairTemplate = RepairTemplate {
567    id: "control-flow/remove-dead",
568    summary: "Remove the unreachable code",
569    safety: RepairSafety::BehaviorPreserving,
570};
571
572const REPAIR_STDLIB_MIGRATE_RENAMED: RepairTemplate = RepairTemplate {
573    id: "stdlib/migrate-renamed",
574    summary: "Rename the call to the renamed stdlib symbol",
575    safety: RepairSafety::ScopeLocal,
576};
577
578const REPAIR_BINDINGS_ATTENUATE_HARNESS: RepairTemplate = RepairTemplate {
579    id: "bindings/attenuate-harness",
580    summary: "Replace the root Harness parameter with the single capability the helper uses",
581    safety: RepairSafety::SurfaceChanging,
582};
583
584const REPAIR_LLM_MIGRATE_REMOVED_OPTION: RepairTemplate = RepairTemplate {
585    id: "llm/migrate-removed-option",
586    summary: "Replace the removed option with its supported equivalent",
587    safety: RepairSafety::ScopeLocal,
588};
589
590const REPAIR_LLM_ADD_SCHEMA: RepairTemplate = RepairTemplate {
591    id: "llm/add-schema",
592    summary: "Add a typed output schema to the LLM call",
593    safety: RepairSafety::SurfaceChanging,
594};
595
596const REPAIR_LLM_USE_CAPABILITY_FLAG: RepairTemplate = RepairTemplate {
597    id: "llm/use-capability-flag",
598    summary: "Branch on a capability flag instead of provider identity",
599    safety: RepairSafety::CapabilityChanging,
600};
601
602const REPAIR_PROMPTS_ESCAPE_INJECTION: RepairTemplate = RepairTemplate {
603    id: "prompts/escape-injection",
604    summary: "Pass the untrusted input through a structured placeholder",
605    safety: RepairSafety::ScopeLocal,
606};
607
608const REPAIR_PROMPTS_ADD_TOOL_TO_SURFACE: RepairTemplate = RepairTemplate {
609    id: "prompts/add-tool-to-surface",
610    summary: "Add the referenced tool to the declared tool surface",
611    safety: RepairSafety::SurfaceChanging,
612};
613
614const REPAIR_STYLE_RENAME_TO_CONVENTION: RepairTemplate = RepairTemplate {
615    id: "style/rename-to-convention",
616    summary: "Rename to match the casing convention for this kind",
617    safety: RepairSafety::SurfaceChanging,
618};
619
620const REPAIR_TYPES_ADD_SHAPE_ANNOTATION: RepairTemplate = RepairTemplate {
621    id: "types/add-shape-annotation",
622    summary: "Annotate the dict with a concrete shape type",
623    safety: RepairSafety::SurfaceChanging,
624};
625
626/// The repair for a parameter that never got a type.
627///
628/// Surface-changing rather than scope-local: the annotation lands on a
629/// signature, and once it is there every caller is checked against it. That is
630/// the point of the repair, and it is also why it is not auto-applied under a
631/// lower ceiling. `harn fix` infers the type from the body and the call sites,
632/// so the mechanical part of the migration is covered; `unknown` is what it
633/// writes when it can prove nothing, preserving the need to narrow dynamic
634/// values before use.
635const REPAIR_TYPES_ANNOTATE_PARAMETER: RepairTemplate = RepairTemplate {
636    id: "types/annotate-parameter",
637    summary: "Annotate the parameter with the inferred type, or `unknown` and narrow it at the dynamic boundary",
638    safety: RepairSafety::SurfaceChanging,
639};
640
641/// The repair for a boundary value read without validation.
642///
643/// Since harn#6252 a binding annotation *is* enforced, so annotating a
644/// `json_parse` result does validate it — the original reason for keeping
645/// `types/add-shape-annotation` away from this rule (that the annotation was
646/// erased, and so removed the diagnostic without removing the hazard) no longer
647/// holds.
648///
649/// This still offers schema validation rather than the annotation, for a
650/// different and narrower reason: a binding assertion reports the declared type
651/// and the value's kind, while `schema_expect` reports which field failed and
652/// why. For an untrusted payload that difference is the whole diagnosis. The
653/// annotation is now a correct fix; it is not the most informative one, and a
654/// one-step automated repair should offer the most informative.
655const REPAIR_TYPES_VALIDATE_BOUNDARY_VALUE: RepairTemplate = RepairTemplate {
656    id: "types/validate-boundary-value",
657    summary: "Validate the parsed value with schema_expect() or schema_check() before reading it",
658    safety: RepairSafety::ScopeLocal,
659};
660
661const REPAIR_MANUAL_REVIEW_CAPABILITY: RepairTemplate = RepairTemplate {
662    id: "manual/review-capability-binding",
663    summary: "Review the capability binding; the fix is not mechanical",
664    safety: RepairSafety::NeedsHuman,
665};
666
667const REPAIR_POLICY_NARROW_CHILD_EFFECTS: RepairTemplate = RepairTemplate {
668    id: "policy/narrow-child-effects",
669    summary: "Narrow the child agent's effects to a subset of the parent's, or widen the parent's declared effects",
670    safety: RepairSafety::SurfaceChanging,
671};
672
673const REPAIR_MANUAL_NEEDS_HUMAN: RepairTemplate = RepairTemplate {
674    id: "manual/needs-human",
675    summary: "Plan a human-led change; auto-apply is not safe here",
676    safety: RepairSafety::NeedsHuman,
677};
678
679/// Every repair template registered by [`Code::repair_template`], in source
680/// order for catalog generation and health checks.
681pub const REPAIR_REGISTRY: &[&RepairTemplate] = &[
682    &REPAIR_INSERT_EXPLICIT_CONVERSION,
683    &REPAIR_REWRITE_STRING_INTERPOLATION,
684    &REPAIR_CASTS_REMOVE_UNCHECKED,
685    &REPAIR_CASTS_REMOVE_REDUNDANT,
686    &REPAIR_BINDINGS_RENAME_TO_CLOSEST,
687    &REPAIR_BINDINGS_MAKE_MUTABLE,
688    &REPAIR_BINDINGS_MAKE_IMMUTABLE,
689    &REPAIR_BINDINGS_RENAME_UNUSED,
690    &REPAIR_BINDINGS_REMOVE_UNUSED_PIPELINE_INPUT,
691    &REPAIR_BINDINGS_NAME_CAPABILITY_PARAMETER,
692    &REPAIR_BINDINGS_RENAME_SHADOW,
693    &REPAIR_BINDINGS_THREAD_HARNESS,
694    &REPAIR_BINDINGS_THREAD_HARNESS_NEEDS_PARAM,
695    &REPAIR_BINDINGS_THREAD_HARNESS_METHOD,
696    &REPAIR_BINDINGS_THREAD_HARNESS_CLOCK,
697    &REPAIR_BINDINGS_THREAD_HARNESS_FS,
698    &REPAIR_BINDINGS_THREAD_HARNESS_ENV,
699    &REPAIR_BINDINGS_THREAD_HARNESS_RANDOM,
700    &REPAIR_BINDINGS_THREAD_HARNESS_NET,
701    &REPAIR_DECLARATIONS_REMOVE_UNUSED,
702    &REPAIR_IMPORTS_FIX_PATH,
703    &REPAIR_IMPORTS_REMOVE_UNUSED,
704    &REPAIR_IMPORTS_REORDER,
705    &REPAIR_ERRORS_CHECK_OR_RESCUE,
706    &REPAIR_ERRORS_WRAP_IN_FN,
707    &REPAIR_MATCH_ADD_MISSING_ARMS,
708    &REPAIR_MATCH_REMOVE_DUPLICATE_ARM,
709    &REPAIR_FORMAT_REFORMAT,
710    &REPAIR_DOC_COMMENT_MIGRATE,
711    &REPAIR_DOC_ADD_HARNDOC,
712    &REPAIR_DOC_ADD_STDLIB_METADATA,
713    &REPAIR_BLOCK_REMOVE_EMPTY,
714    &REPAIR_CONTROL_FLOW_FLATTEN,
715    &REPAIR_EXPRESSION_SIMPLIFY,
716    &REPAIR_RECORDS_PICK_FIELDS,
717    &REPAIR_CLONE_REMOVE_REDUNDANT,
718    &REPAIR_COLLECTION_PREFER_LAZY,
719    &REPAIR_DEAD_CODE_REMOVE,
720    &REPAIR_STDLIB_MIGRATE_RENAMED,
721    &REPAIR_BINDINGS_ATTENUATE_HARNESS,
722    &REPAIR_LLM_MIGRATE_REMOVED_OPTION,
723    &REPAIR_LLM_ADD_SCHEMA,
724    &REPAIR_LLM_USE_CAPABILITY_FLAG,
725    &REPAIR_PROMPTS_ESCAPE_INJECTION,
726    &REPAIR_PROMPTS_ADD_TOOL_TO_SURFACE,
727    &REPAIR_STYLE_RENAME_TO_CONVENTION,
728    &REPAIR_TYPES_ADD_SHAPE_ANNOTATION,
729    &REPAIR_TYPES_ANNOTATE_PARAMETER,
730    &REPAIR_TYPES_VALIDATE_BOUNDARY_VALUE,
731    &REPAIR_MANUAL_REVIEW_CAPABILITY,
732    &REPAIR_MANUAL_NEEDS_HUMAN,
733    &REPAIR_POLICY_NARROW_CHILD_EFFECTS,
734];
735
736#[cfg(test)]
737mod tests {
738    use super::super::Category;
739    use super::{Code, ParseRepairSafetyError, RepairSafety, REPAIR_REGISTRY};
740    use std::collections::HashSet;
741    use std::str::FromStr;
742
743    #[test]
744    fn parses_registered_code() {
745        assert_eq!(Code::from_str("HARN-TYP-014"), Ok(Code::TypeParameterArity));
746    }
747
748    #[test]
749    fn registry_has_unique_identifiers() {
750        let mut seen = HashSet::new();
751        for entry in Code::registry() {
752            assert!(
753                seen.insert(entry.identifier),
754                "duplicate diagnostic code {}",
755                entry.identifier
756            );
757            assert_eq!(entry.code.as_str(), entry.identifier);
758            assert_eq!(entry.code.category(), entry.category);
759            let expected_prefix = format!("HARN-{}-", entry.category);
760            assert!(entry.identifier.starts_with(&expected_prefix));
761            let suffix = entry.identifier.trim_start_matches(&expected_prefix);
762            assert_eq!(suffix.len(), 3);
763            assert!(suffix.chars().all(|ch| ch.is_ascii_digit()));
764            assert!(!entry.summary.is_empty());
765        }
766        assert!(Code::registry().len() >= 40);
767    }
768
769    #[test]
770    fn every_category_is_populated() {
771        for category in Category::ALL {
772            assert!(
773                Code::registry()
774                    .iter()
775                    .any(|entry| entry.category == *category),
776                "missing diagnostic code category {category}"
777            );
778        }
779    }
780
781    #[test]
782    fn every_code_has_non_empty_explanation() {
783        for entry in Code::registry() {
784            let body = entry.code.explanation();
785            assert!(
786                !body.trim().is_empty(),
787                "diagnostic code {} has an empty explanation file",
788                entry.identifier
789            );
790            assert!(
791                body.contains(entry.identifier),
792                "explanation for {} should reference its identifier",
793                entry.identifier
794            );
795        }
796    }
797
798    #[test]
799    fn related_codes_are_registered_and_non_self() {
800        for entry in Code::registry() {
801            for &other in entry.code.related() {
802                assert_ne!(
803                    other, entry.code,
804                    "{} lists itself as a related code",
805                    entry.identifier
806                );
807                assert!(
808                    Code::registry().iter().any(|e| e.code == other),
809                    "{} lists unregistered related code {}",
810                    entry.identifier,
811                    other
812                );
813            }
814        }
815    }
816
817    #[test]
818    fn repair_safety_string_roundtrip() {
819        for safety in RepairSafety::ALL {
820            let parsed = RepairSafety::from_str(safety.as_str()).unwrap();
821            assert_eq!(parsed, *safety);
822            assert_eq!(parsed.to_string(), safety.as_str());
823        }
824        assert_eq!(
825            RepairSafety::from_str("not-a-safety-class"),
826            Err(ParseRepairSafetyError)
827        );
828    }
829
830    #[test]
831    fn repair_safety_ordering_is_monotonic_low_to_high() {
832        // The is_at_most ceiling check relies on this ordering being
833        // least-to-most disruptive; a regression here flips the meaning
834        // of `harn fix --safety <ceiling>` for every caller.
835        let order = RepairSafety::ALL;
836        for window in order.windows(2) {
837            assert!(
838                window[0] < window[1],
839                "{:?} should be safer than {:?}",
840                window[0],
841                window[1]
842            );
843            assert!(window[0].is_at_most(window[1]));
844            assert!(!window[1].is_at_most(window[0]));
845        }
846    }
847
848    #[test]
849    fn only_behavior_preserving_repairs_are_machine_applicable() {
850        assert!(RepairSafety::FormatOnly.is_machine_applicable());
851        assert!(RepairSafety::BehaviorPreserving.is_machine_applicable());
852        for safety in [
853            RepairSafety::ScopeLocal,
854            RepairSafety::SurfaceChanging,
855            RepairSafety::CapabilityChanging,
856            RepairSafety::NeedsHuman,
857        ] {
858            assert!(!safety.is_machine_applicable(), "{safety}");
859        }
860    }
861
862    #[test]
863    fn repair_registry_has_at_least_twenty_entries() {
864        assert!(
865            REPAIR_REGISTRY.len() >= 20,
866            "expected ≥20 repair templates, found {}",
867            REPAIR_REGISTRY.len()
868        );
869    }
870
871    #[test]
872    fn repair_ids_are_kebab_case_namespaced_and_unique() {
873        let mut seen = HashSet::new();
874        for template in REPAIR_REGISTRY {
875            assert!(
876                seen.insert(template.id),
877                "duplicate repair id {}",
878                template.id
879            );
880            let (namespace, leaf) = template.id.split_once('/').unwrap_or_else(|| {
881                panic!(
882                    "repair id `{}` is missing `<namespace>/` prefix",
883                    template.id
884                )
885            });
886            assert!(
887                !namespace.is_empty() && !leaf.is_empty(),
888                "repair id `{}` has empty namespace or leaf",
889                template.id
890            );
891            for ch in template.id.chars() {
892                assert!(
893                    ch.is_ascii_lowercase() || ch.is_ascii_digit() || ch == '-' || ch == '/',
894                    "repair id `{}` has non-kebab character {ch:?}",
895                    template.id
896                );
897            }
898            assert!(
899                !template.summary.is_empty(),
900                "repair {} has empty summary",
901                template.id
902            );
903            // Summaries are imperative: start with a capital ASCII letter.
904            let first = template.summary.chars().next().unwrap();
905            assert!(
906                first.is_ascii_uppercase(),
907                "repair {} summary `{}` should start with a capital",
908                template.id,
909                template.summary
910            );
911        }
912    }
913
914    #[test]
915    fn manual_namespace_is_needs_human() {
916        for template in REPAIR_REGISTRY {
917            if let Some(("manual", _)) = template.id.split_once('/') {
918                assert_eq!(
919                    template.safety,
920                    RepairSafety::NeedsHuman,
921                    "manual/* repair {} must be NeedsHuman",
922                    template.id
923                );
924            }
925        }
926    }
927
928    #[test]
929    fn known_codes_carry_expected_safety_class() {
930        // Spot-check: the autonomy contract for several representative
931        // diagnostics. Lock in the safety class so cross-repo agents that
932        // dispatch on these don't silently drift when the catalog moves.
933        let expected: &[(Code, RepairSafety, &str)] = &[
934            (
935                Code::FormatterWouldReformat,
936                RepairSafety::FormatOnly,
937                "format/reformat",
938            ),
939            (
940                Code::ModuleImportUnused,
941                RepairSafety::BehaviorPreserving,
942                "imports/remove-unused",
943            ),
944            (
945                Code::ImmutableAssignment,
946                RepairSafety::ScopeLocal,
947                "bindings/make-mutable",
948            ),
949            (
950                Code::LintUnusedFunction,
951                RepairSafety::SurfaceChanging,
952                "declarations/remove-unused",
953            ),
954            (
955                Code::LlmProviderIdentityBranch,
956                RepairSafety::CapabilityChanging,
957                "llm/use-capability-flag",
958            ),
959            (
960                Code::PromptVariantExplosion,
961                RepairSafety::NeedsHuman,
962                "manual/needs-human",
963            ),
964            (
965                Code::NonExhaustiveMatch,
966                RepairSafety::ScopeLocal,
967                "match/add-missing-arms",
968            ),
969            (
970                Code::LintAmbientClockBuiltin,
971                RepairSafety::ScopeLocal,
972                "bindings/thread-harness-clock",
973            ),
974            (
975                Code::LintAmbientStdioBuiltin,
976                RepairSafety::ScopeLocal,
977                "bindings/thread-harness",
978            ),
979            (
980                Code::InvalidMainSignature,
981                RepairSafety::SurfaceChanging,
982                "bindings/thread-harness-needs-param",
983            ),
984        ];
985        for (code, safety, repair_id) in expected {
986            let template = code
987                .repair_template()
988                .unwrap_or_else(|| panic!("{code} should have a repair template"));
989            assert_eq!(template.safety, *safety, "{code} safety class drifted");
990            assert_eq!(template.id, *repair_id, "{code} repair id drifted");
991        }
992    }
993
994    #[test]
995    fn repair_templates_cover_at_least_twenty_codes() {
996        let covered = Code::ALL
997            .iter()
998            .filter(|code| code.repair_template().is_some())
999            .count();
1000        assert!(
1001            covered >= 20,
1002            "expected ≥20 codes with a repair template, found {covered}"
1003        );
1004    }
1005
1006    /// A rule about validating a boundary value cannot be repaired by an
1007    /// annotation.
1008    ///
1009    /// An annotation is erased before the value exists: annotating a
1010    /// `json_parse` result reads an int out of a field declared `string` and
1011    /// accepts an array as a record, with no diagnostic at either compile time
1012    /// or run time. Offering it as the one-step repair for these codes would
1013    /// auto-apply the escape the codes exist to close, and a repair is applied
1014    /// more readily than help text is read (harn#6234).
1015    ///
1016    /// `LintUnnormalizedOptions` is deliberately not in this list. It is about
1017    /// an inline options dict bypassing the typed option constructors, where no
1018    /// untrusted payload is involved and naming the shape is the whole fix.
1019    #[test]
1020    fn boundary_validation_codes_offer_the_most_informative_repair() {
1021        for code in [Code::BoundaryValueUnvalidated, Code::LintUntypedDictAccess] {
1022            let Some(template) = code.repair_template() else {
1023                continue;
1024            };
1025            assert_ne!(
1026                template.id, "types/add-shape-annotation",
1027                "{code:?} is a boundary-validation rule; an annotation validates the value \
1028                 (harn#6252) but reports only the declared type and the value's kind, so the \
1029                 offered one-step repair must be the one that names the failing field"
1030            );
1031        }
1032    }
1033
1034    #[test]
1035    fn every_registered_repair_is_referenced_by_some_code() {
1036        let referenced: HashSet<&'static str> = Code::ALL
1037            .iter()
1038            .filter_map(|code| code.repair_template())
1039            .map(|template| template.id)
1040            .collect();
1041        for template in REPAIR_REGISTRY {
1042            assert!(
1043                referenced.contains(template.id),
1044                "repair {} is in REPAIR_REGISTRY but no Code maps to it",
1045                template.id
1046            );
1047        }
1048    }
1049
1050    #[test]
1051    fn every_referenced_repair_template_is_in_registry() {
1052        let registered: HashSet<&'static str> =
1053            REPAIR_REGISTRY.iter().map(|template| template.id).collect();
1054        for code in Code::ALL {
1055            let Some(template) = code.repair_template() else {
1056                continue;
1057            };
1058            assert!(
1059                registered.contains(template.id),
1060                "repair {} (used by {}) is missing from REPAIR_REGISTRY",
1061                template.id,
1062                code
1063            );
1064        }
1065    }
1066}
harn_parser/diagnostic_codes/repairs.rs

harn_parser/diagnostic_codes/
repairs.rs
