Drop invalid OpenAPI schema examples (#7325)

Author: tim-smart

.changeset/fix-invalid-openapi-examples.md

@@ -0,0 +1,5 @@
+---
+"@effect/openapi-generator": patch
+---
+
+Drop invalid OpenAPI schema examples from generated Effect Schema annotations.

packages/tools/openapi-generator/src/JsonSchemaGenerator.ts

@@ -21,6 +21,7 @@
 import * as Arr from "effect/Array"
 import * as JsonSchema from "effect/JsonSchema"
 import * as Rec from "effect/Record"
+import * as Schema from "effect/Schema"
 import * as SchemaRepresentation from "effect/SchemaRepresentation"
 
 type Source = "openapi-3.0" | "openapi-3.1"
@@ -211,17 +212,48 @@ function makeWithRepresentation() {
       schemas,
       definitions
     }
+    const schemasWithExamples: Array<JsonSchema.JsonSchema> = []
+    const preparedSchemas = new WeakMap<JsonSchema.JsonSchema, JsonSchema.JsonSchema>()
+    const preparedOutputs = new WeakSet<JsonSchema.JsonSchema>()
     const importerOptions: SchemaRepresentation.FromJsonSchemaOptions = {
       patterns: "apply",
       onEnter(js: JsonSchema.JsonSchema) {
+        if (preparedOutputs.has(js)) return js
+        const cached = preparedSchemas.get(js)
+        if (cached !== undefined) return cached
+
         const out = { ...js }
         if (out.type === "object" && out.additionalProperties === undefined) {
           out.additionalProperties = false
         }
-        return options?.onEnter === undefined ? out : options.onEnter(out)
+        const transformed = { ...(options?.onEnter === undefined ? out : options.onEnter(out)) }
+        preparedSchemas.set(js, transformed)
+        preparedOutputs.add(transformed)
+        if (Array.isArray(transformed.examples)) {
+          schemasWithExamples.push(transformed)
+        }
+        return transformed
+      }
+    }
+    let rootSchemas = SchemaRepresentation.fromJsonSchemaMultiDocument(document, importerOptions)
+    if (Arr.isArrayNonEmpty(schemasWithExamples)) {
+      const exampleSchemas = SchemaRepresentation.fromJsonSchemaMultiDocument(
+        { ...document, schemas: schemasWithExamples },
+        importerOptions
+      )
+      for (let i = 0; i < schemasWithExamples.length; i++) {
+        const node = schemasWithExamples[i]
+        const examples = node.examples as ReadonlyArray<unknown>
+        const validExamples = examples.filter(Schema.is(exampleSchemas[i]))
+        if (validExamples.length === examples.length) continue
+        if (validExamples.length === 0) {
+          delete node.examples
+        } else {
+          node.examples = validExamples
+        }
       }
+      rootSchemas = SchemaRepresentation.fromJsonSchemaMultiDocument(document, importerOptions)
     }
-    const rootSchemas = SchemaRepresentation.fromJsonSchemaMultiDocument(document, importerOptions)
     const codeDocument = SchemaRepresentation.toCodeDocument(
       SchemaRepresentation.toRepresentations(Arr.map(rootSchemas, (schema) => schema.ast))
     )

packages/tools/openapi-generator/test/OpenApiGenerator.test.ts

@@ -2718,6 +2718,45 @@ export const __HttpApiMultipartFiles = Multipart.FilesSchema`,
   })
 
   describe("regression", () => {
+    it.effect("emits compilable clients when schema examples are invalid", () =>
+      assertGeneratedClientsCompile({
+        openapi: "3.0.3",
+        info: {
+          title: "Invalid examples API",
+          version: "1.0.0"
+        },
+        paths: {
+          "/triggers": {
+            get: {
+              operationId: "getTriggers",
+              parameters: [],
+              responses: {
+                200: {
+                  description: "OK",
+                  content: {
+                    "application/json": {
+                      schema: {
+                        type: "array",
+                        items: { type: "string" },
+                        example: "create"
+                      }
+                    }
+                  }
+                }
+              },
+              tags: ["Triggers"],
+              security: []
+            }
+          }
+        },
+        components: {
+          schemas: {},
+          securitySchemes: {}
+        },
+        security: [],
+        tags: [{ name: "Triggers" }]
+      } as unknown as OpenAPISpec))
+
     it.effect("runtime warnings do not report additional-tags-dropped outside httpapi", () =>
       assertRuntimeStableWithWarnings(
         {