feat: support schema changes classification for AsyncAPI

.cursor/rules/asyncapi-testing.mdc

@@ -0,0 +1,105 @@
+---
+description: AsyncAPI test writing standards and patterns
+globs: test/**/*.test.ts
+alwaysApply: false
+---
+
+# AsyncAPI Test Writing Standards
+
+## 1. Validate Test Specifications
+
+**All test specs MUST be valid AsyncAPI specifications** unless intentionally testing error handling.
+
+### Pattern: Valid Specifications
+
+```typescript
+// ✅ GOOD: Define spec as constant, then validate
+const before = {
+  asyncapi: '3.0.0',
+  info: {
+    title: 'Test API',
+    version: '1.0.0',
+  },
+  channels: {
+    testChannel: {}
+  }
+}
+...
+
+await parseAsyncApiAndAssertValid(before)
+await parseAsyncApiAndAssertValid(after)
+
+const { merged, diffs } = apiDiff(before, after, COMPARE_OPTIONS)
+// ... assertions
+```
+
+### Pattern: Intentionally Invalid Specifications
+
+When testing error handling or invalid specs, **clearly document with a comment**:
+
+```typescript
+// ✅ GOOD: Commented validation with explanation
+const source = {
+  asyncapi: '3.0.0',
+  // Missing required 'info' field
+}
+
+// await parseAsyncApiAndAssertValid(source) // intentionally not valid source
+
+const result = unify(source, { unify: true })
+// ... test error handling
+```
+
+## 2. Use Helper Functions for Complex Specs
+
+Create well-documented helper functions to reduce boilerplate:
+
+```typescript
+/**
+ * Helper function to create AsyncAPI document with schema in components
+ * @param schemaDefinition - The schema definition
+ * @param schemaFormat - Optional schema format:
+ *   - undefined: creates regular schema (default)
+ *   - string value: creates Multi Format Schema with schemaFormat property
+ */
+const createAsyncAPIWithSchema = (
+  schemaDefinition: unknown,
+  schemaFormat?: string
+) => {
+  return {
+    asyncapi: '3.0.0',
+    info: {
+      title: 'Test API',
+      version: '1.0.0',
+    },
+    components: {
+      schemas: {
+        TestSchema: schemaFormat
+          ? { schemaFormat, schema: schemaDefinition }
+          : schemaDefinition,
+      },
+    },
+  }
+}
+```
+
+## 3. Required Fields for Valid Specs
+
+All valid AsyncAPI 3.0.0 specs must include:
+
+```typescript
+{
+  asyncapi: '3.0.0',  // Required
+  info: {              // Required
+    title: 'Test API', // Required
+    version: '1.0.0',  // Required
+  },
+  // ... other properties
+}
+```
+
+## 4. Test Organization
+
+- Define `COMPARE_OPTIONS` constants at the top of describe blocks
+- Keep spec definitions close to where they're used
+- Use descriptive variable names (`before`, `after`, or domain-specific names)