refactor(validation): extract shared info-object validation

CONTEXT.md

@@ -20,6 +20,12 @@ A document flaw that contradicts a rule of the applicable OpenAPI dialect: a REQ
 
 genoc enforces exactly what the spec prose mandates — presence and type, never value quality the spec leaves unconstrained: `info.title: ""` is a valid title. A document that is valid but beyond genoc (3.2, external `$ref`s) is an unsupported feature, not a spec violation.
 
+## Shared rule
+
+A validation rule stated identically by more than one dialect, so its check lives once in a shared module under `src/parser/version/` (`validate-security.ts`, `validate-info.ts`) rather than in each dialect's validator file. The module takes the dialect as a parameter — `(spec, version, errors)` — and renders its own spec links, so the same message cites each dialect's own spec page.
+
+Rules that are identical except for a small delta parameterize the delta per version inside the shared module (security scheme types, for instance); genuinely dialect-specific rules stay in the per-dialect validator files. The published dialects are frozen documents, so a rule identical across two of them stays identical — sharing costs nothing and keeps genoc-side changes out of lockstep edits.
+
 ## Security Scheme
 
 One named authentication mechanism, declared in `components.securitySchemes` — the only declaration site in both 3.0 and 3.1 (external-document references are outside the boundary). Typed by `type`: `apiKey`, `http`, `oauth2`, `openIdConnect`, plus `mutualTLS` in 3.1 only.

src/parser/version/v3.0/validator.ts

@@ -1,4 +1,5 @@
 import { specViolation, type SpecLinkKey } from '../spec-links.js';
+import { validateInfo } from '../validate-info.js';
 import { validateSecurity } from '../validate-security.js';
 import type { ValidationResult } from '../validate.js';
 
@@ -14,7 +15,7 @@ const violation = (key: SpecLinkKey, message: string): string => specViolation('
  * 3.0-specific validation rules:
  * - `openapi` must start with "3.0"
  * - `paths` is required (unlike 3.1 where paths/components/webhooks is flexible)
- * - `info` with `title` and `version` required
+ * - `info` with `title` and `version` required (shared rule)
  * - Warns about 3.1-only features: `webhooks`, `$schema` in schemas, `type` as array
  * - Accepts `nullable` and `example` (valid in 3.0, not in 3.1)
  * - Errors on `items` as array (3.1-only tuple syntax)
@@ -44,23 +45,7 @@ export function validateSpec30(spec: unknown): ValidationResult {
     );
   }
 
-  if (!s.info || typeof s.info !== 'object' || Array.isArray(s.info)) {
-    errors.push(
-      violation('info-object', "OpenAPI specification must have an 'info' field with object value")
-    );
-  } else {
-    const info = s.info as Record<string, unknown>;
-    if (typeof info.title !== 'string') {
-      errors.push(
-        violation('info-title', "Info object must have a 'title' field with string value")
-      );
-    }
-    if (typeof info.version !== 'string') {
-      errors.push(
-        violation('info-version', "Info object must have a 'version' field with string value")
-      );
-    }
-  }
+  validateInfo(s, '3.0', errors);
 
   if (!s.paths || typeof s.paths !== 'object' || Array.isArray(s.paths)) {
     errors.push(

src/parser/version/v3.1/validator.ts

@@ -1,4 +1,5 @@
 import { specViolation, type SpecLinkKey } from '../spec-links.js';
+import { validateInfo } from '../validate-info.js';
 import { validateSecurity } from '../validate-security.js';
 import type { ValidationResult } from '../validate.js';
 
@@ -14,7 +15,7 @@ const violation = (key: SpecLinkKey, message: string): string => specViolation('
  * 3.1-specific validation rules:
  * - `openapi` must start with "3.1"
  * - at least one of `paths`, `components`, or `webhooks` (unlike 3.0 where `paths` is required)
- * - `info` with `title` and `version` required
+ * - `info` with `title` and `version` required (shared rule)
  * - `paths` must be an object when present
  * - `components.schemas` entries must be objects, validated recursively for 3.0-only features
  * - Warns about 3.0-only features in schemas: `nullable`, boolean `exclusiveMinimum`/`exclusiveMaximum`,
@@ -48,23 +49,7 @@ export function validateSpec31(spec: unknown): ValidationResult {
     );
   }
 
-  if (!s.info || typeof s.info !== 'object' || Array.isArray(s.info)) {
-    errors.push(
-      violation('info-object', "OpenAPI specification must have an 'info' field with object value")
-    );
-  } else {
-    const info = s.info as Record<string, unknown>;
-    if (typeof info.title !== 'string') {
-      errors.push(
-        violation('info-title', "Info object must have a 'title' field with string value")
-      );
-    }
-    if (typeof info.version !== 'string') {
-      errors.push(
-        violation('info-version', "Info object must have a 'version' field with string value")
-      );
-    }
-  }
+  validateInfo(s, '3.1', errors);
 
   if (!s.paths && !s.components && !s.webhooks) {
     // Not a spec violation: all three fields are optional in 3.1; the check

src/parser/version/validate-info.ts

@@ -0,0 +1,46 @@
+/**
+ * Shared Info Object validation for the 3.0 and 3.1 validators.
+ *
+ * Rules are identical across dialects — every published dialect (3.0, 3.1,
+ * 3.2 alike) requires `info` to be an object carrying `title` and `version`
+ * strings. Presence and type only: the spec puts no constraint on the
+ * values, so `title: ""` is a valid title.
+ */
+
+import { specViolation } from './spec-links.js';
+
+export function validateInfo(
+  spec: Record<string, unknown>,
+  version: '3.0' | '3.1',
+  errors: string[]
+): void {
+  if (!spec.info || typeof spec.info !== 'object' || Array.isArray(spec.info)) {
+    errors.push(
+      specViolation(
+        version,
+        'info-object',
+        "OpenAPI specification must have an 'info' field with object value"
+      )
+    );
+    return;
+  }
+  const info = spec.info as Record<string, unknown>;
+  if (typeof info.title !== 'string') {
+    errors.push(
+      specViolation(
+        version,
+        'info-title',
+        "Info object must have a 'title' field with string value"
+      )
+    );
+  }
+  if (typeof info.version !== 'string') {
+    errors.push(
+      specViolation(
+        version,
+        'info-version',
+        "Info object must have a 'version' field with string value"
+      )
+    );
+  }
+}

tests/unit/version/validate-info.test.ts

@@ -0,0 +1,64 @@
+import { describe, expect, it } from 'vitest';
+
+import { validateInfo } from '../../../src/parser/version/validate-info.js';
+
+function run(spec: Record<string, unknown>, version: '3.0' | '3.1'): string[] {
+  const errors: string[] = [];
+  validateInfo(spec, version, errors);
+  return errors;
+}
+
+// Spec pages are hardcoded instead of importing SPEC_PAGE: these tests must
+// fail loudly if link rendering ever changes. When a spec patch release bumps
+// SPEC_PAGE, update these expectations in the same commit.
+const DIALECTS = [
+  { version: '3.0', page: 'https://spec.openapis.org/oas/v3.0.4.html' },
+  { version: '3.1', page: 'https://spec.openapis.org/oas/v3.1.1.html' },
+] as const;
+
+describe('validateInfo', () => {
+  it.each(DIALECTS)(
+    'rejects a missing or non-object info with the exact %s link',
+    ({ version, page }) => {
+      for (const info of [undefined, null, 'nope', [], 42]) {
+        const spec: Record<string, unknown> = info === undefined ? {} : { info };
+        expect(run(spec, version)).toEqual([
+          `OpenAPI specification must have an 'info' field with object value\n    ${page}#info-object`,
+        ]);
+      }
+    }
+  );
+
+  it.each(DIALECTS)(
+    'rejects a non-string info.title with the exact %s link',
+    ({ version, page }) => {
+      for (const title of [undefined, null, 42, ['T']]) {
+        expect(run({ info: { title, version: '1.0.0' } }, version)).toEqual([
+          `Info object must have a 'title' field with string value\n    ${page}#info-title`,
+        ]);
+      }
+    }
+  );
+
+  it.each(DIALECTS)(
+    'rejects a non-string info.version with the exact %s link',
+    ({ version, page }) => {
+      for (const badVersion of [undefined, null, 42, ['1']]) {
+        expect(run({ info: { title: 'Test', version: badVersion } }, version)).toEqual([
+          `Info object must have a 'version' field with string value\n    ${page}#info-version`,
+        ]);
+      }
+    }
+  );
+
+  it.each(DIALECTS)(
+    'accepts empty-string title and version in %s (spec constrains presence only)',
+    ({ version }) => {
+      expect(run({ info: { title: '', version: '' } }, version)).toEqual([]);
+    }
+  );
+
+  it.each(DIALECTS)('accepts a fully valid info object in %s', ({ version }) => {
+    expect(run({ info: { title: 'Test', version: '1.0.0' } }, version)).toEqual([]);
+  });
+});