fix(e2e-compare): actually compare setClassMetadata between compilers

napi/angular-compiler/e2e/compare/fixtures/known-differences.ts

@@ -13,6 +13,8 @@ interface KnownDifference {
   fields: string[]
   /** Every import difference, exactly as `compareImports` reports it. */
   importDiffs?: ImportDiff[]
+  /** Every setClassMetadata difference, as `Class.field`, e.g. `MyComponent.setClassMetadata`. */
+  metadataDiffs?: string[]
   /** Why each difference exists. */
   reasons: string[]
 }
@@ -33,6 +35,8 @@ const INJECTABLE_FACTORY_WRAPPER =
   'an @Injectable useFactory is wrapped in a function expression where Angular emits an arrow function'
 const SET_CLASS_METADATA_IMPORT =
   'Oxc keeps the @Inject import because its setClassMetadata references it; ngtsc emits the same reference but TypeScript elision still drops the import (upstream emit bug)'
+const CTOR_PARAM_TYPE =
+  'ctorParams emits the parameter`s type name where ngtsc emits type: undefined for type-only annotations (Oxc emit bug, issue #563)'
 const ALIASED_INJECTABLE =
   'an aliased @Injectable compiles to a broken ɵprov under ngtsc — its needsFactory check compares the written decorator name, so the factory (and setClassMetadata) are never emitted; Oxc emits a working ɵfac (issue #507, kept deliberately)'
 
@@ -59,7 +63,8 @@ export const KNOWN_DIFFERENCES: Record<string, KnownDifference> = {
         actual: ['Inject', 'Injectable', 'InjectionToken'],
       },
     ],
-    reasons: [SET_CLASS_METADATA_IMPORT],
+    metadataDiffs: ['TestableService.setClassMetadata.ctorParams'],
+    reasons: [SET_CLASS_METADATA_IMPORT, CTOR_PARAM_TYPE],
   },
   'class-metadata/class-metadata-with-inject': {
     fields: [],
@@ -71,7 +76,8 @@ export const KNOWN_DIFFERENCES: Record<string, KnownDifference> = {
         actual: ['Component', 'Inject', 'InjectionToken'],
       },
     ],
-    reasons: [SET_CLASS_METADATA_IMPORT],
+    metadataDiffs: ['InjectMetaComponent.setClassMetadata.ctorParams'],
+    reasons: [SET_CLASS_METADATA_IMPORT, CTOR_PARAM_TYPE],
   },
   'full-file/component-with-services': {
     fields: [],
@@ -83,7 +89,8 @@ export const KNOWN_DIFFERENCES: Record<string, KnownDifference> = {
         actual: ['Component', 'Inject', 'InjectionToken', 'inject'],
       },
     ],
-    reasons: [SET_CLASS_METADATA_IMPORT],
+    metadataDiffs: ['ComponentWithServices.setClassMetadata.ctorParams'],
+    reasons: [SET_CLASS_METADATA_IMPORT, CTOR_PARAM_TYPE],
   },
   'component-meta/change-detection-default': {
     fields: ['ChangeDetectionDefaultComponent.ɵcmp'],
@@ -111,14 +118,17 @@ export const KNOWN_DIFFERENCES: Record<string, KnownDifference> = {
   },
   'edge-cases/aliased-injectable': {
     fields: ['AliasedService.ɵfac'],
+    metadataDiffs: ['AliasedService.setClassMetadata'],
     reasons: [ALIASED_INJECTABLE],
   },
   'edge-cases/multiple-custom-decorators': {
     fields: ['MultiDecoratorComponent.ɵcmp', 'MultiDecoratorComponent.ɵfac'],
+    metadataDiffs: ['MultiDecoratorComponent.setClassMetadata'],
     reasons: [CUSTOM_DECORATOR],
   },
   'edge-cases/single-custom-decorator': {
     fields: ['MyComponent.ɵcmp', 'MyComponent.ɵfac'],
+    metadataDiffs: ['MyComponent.setClassMetadata'],
     reasons: [CUSTOM_DECORATOR],
   },
   'full-file/component-with-pipes': {

napi/angular-compiler/e2e/compare/fixtures/runner.ts

@@ -156,14 +156,34 @@ async function testFixture(fixture: Fixture, verbose?: boolean): Promise<Fixture
           `import ${diff.moduleSource} expected { ${(diff.expected ?? []).join(', ')} } ` +
           `got { ${(diff.actual ?? []).join(', ')} }`,
       )
-    const allUndocumented = [...undocumented, ...undocumentedImports]
+    const undocumentedMetadata = (result.classMetadataDiffs ?? [])
+      .map((diff) => `${diff.className}.${diff.field}`)
+      .filter((field) => !(known.metadataDiffs ?? []).includes(field))
+    const observedMetadata = new Set(
+      (result.classMetadataDiffs ?? []).map((diff) => `${diff.className}.${diff.field}`),
+    )
+    const unobservedMetadata = (known.metadataDiffs ?? []).filter(
+      (field) => !observedMetadata.has(field),
+    )
+    const allUndocumented = [...undocumented, ...undocumentedImports, ...undocumentedMetadata]
     if (allUndocumented.length > 0) {
       return {
         ...result,
         knownDifferences,
         undocumentedFields: [...new Set(allUndocumented)],
       }
     }
+    // A declared metadata diff that was not observed means the bug was fixed
+    // (or moved) — surface it like a stale entry so the exemption cannot
+    // silently re-allow a regression.
+    if (unobservedMetadata.length > 0) {
+      return {
+        ...result,
+        status: 'mismatch',
+        knownDifferences,
+        staleMetadataFields: unobservedMetadata,
+      }
+    }
     return { ...result, status: 'known-difference', knownDifferences }
   }
   if (result.status === 'match') {
@@ -994,6 +1014,18 @@ export function printFixtureSummary(report: FixtureReport): void {
       console.log(`  ${result.fixture.category}/${result.fixture.name}`)
     }
   }
+  const staleMetadataFixtures = report.fixtures.filter((r) => r.staleMetadataFields)
+  if (staleMetadataFixtures.length > 0) {
+    console.log(
+      '\nStale Metadata Allowlist Entries (declared in known-differences.ts but no longer observed):',
+    )
+    console.log('-'.repeat(50))
+    for (const result of staleMetadataFixtures) {
+      console.log(
+        `  ${result.fixture.category}/${result.fixture.name}: ${result.staleMetadataFields!.join(', ')}`,
+      )
+    }
+  }
 
   // Count feature discrepancies
   const fixturesWithAsymmetricFeatures = report.fixtures.filter(

napi/angular-compiler/e2e/compare/fixtures/types.ts

@@ -288,6 +288,9 @@ export interface FixtureResult {
   /** Fields that differ in a fixture listed in known-differences.ts but are not documented there */
   undocumentedFields?: string[]
 
+  /** `metadataDiffs` entries declared in known-differences.ts that no longer occur */
+  staleMetadataFields?: string[]
+
   /** Oxc compiler output */
   oxcOutput?: FixtureCompilerOutput