Make ResponseValidationError more useful (#91)

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        node-version: [14, 16, 18, 20, 22]
+        node-version: [16, 18, 20, 22]
         os: [ubuntu-latest, windows-latest]
 
     steps:

package.json

@@ -11,8 +11,8 @@
   ],
   "scripts": {
     "build": "tsc",
-    "test": "npm run build && npm run typescript && jest",
-    "test:coverage": "jest --coverage",
+    "test": "npm run build && npm run typescript && vitest",
+    "test:coverage": "vitest --coverage",
     "lint": "eslint .",
     "lint:fix": "eslint --fix . && prettier --write .",
     "typescript": "tsd",
@@ -43,20 +43,19 @@
   "devDependencies": {
     "@fastify/swagger": "^8.14.0",
     "@fastify/swagger-ui": "^3.0.0",
-    "@types/jest": "^29.5.12",
     "@types/node": "^20.12.12",
     "@typescript-eslint/eslint-plugin": "^7.9.0",
     "@typescript-eslint/parser": "^7.9.0",
+    "@vitest/coverage-v8": "^1.6.0",
     "eslint": "^8.57.0",
     "eslint-plugin-import": "^2.29.1",
     "fastify": "^4.27.0",
     "fastify-plugin": "^4.5.1",
-    "jest": "^29.7.0",
     "oas-validator": "^5.0.8",
     "prettier": "^3.2.5",
-    "ts-jest": "^29.1.2",
     "tsd": "^0.31.0",
     "typescript": "^5.4.5",
+    "vitest": "^1.6.0",
     "zod": "^3.23.8"
   },
   "tsd": {

src/ResponseValidationError.ts

@@ -0,0 +1,25 @@
+import type { z, ZodIssue } from 'zod';
+
+export type ResponseValidationErrorDetails = {
+  error: ZodIssue[];
+  method: string;
+  url: string;
+};
+
+export class ResponseValidationError extends Error {
+  public details: ResponseValidationErrorDetails;
+
+  constructor(
+    validationResult: z.SafeParseReturnType<unknown, unknown>,
+    method: string,
+    url: string,
+  ) {
+    super("Response doesn't match the schema");
+    this.name = 'ResponseValidationError';
+    this.details = {
+      error: validationResult.error?.issues ?? [],
+      method,
+      url,
+    };
+  }
+}

src/index.ts

@@ -12,6 +12,8 @@ import type { FastifySerializerCompiler } from 'fastify/types/schema';
 import type { ZodAny, ZodTypeAny, z } from 'zod';
 import { zodToJsonSchema } from 'zod-to-json-schema';
 
+import { ResponseValidationError } from './ResponseValidationError';
+
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 type FreeformRecord = Record<string, any>;
 
@@ -123,18 +125,8 @@ function resolveSchema(maybeSchema: ZodAny | { properties: ZodAny }): Pick<ZodAn
   throw new Error(`Invalid schema passed: ${JSON.stringify(maybeSchema)}`);
 }
 
-export class ResponseValidationError extends Error {
-  public details: FreeformRecord;
-
-  constructor(validationResult: FreeformRecord) {
-    super("Response doesn't match the schema");
-    this.name = 'ResponseValidationError';
-    this.details = validationResult.error;
-  }
-}
-
 export const serializerCompiler: FastifySerializerCompiler<ZodAny | { properties: ZodAny }> =
-  ({ schema: maybeSchema }) =>
+  ({ schema: maybeSchema, method, url }) =>
   (data) => {
     const schema: Pick<ZodAny, 'safeParse'> = resolveSchema(maybeSchema);
 
@@ -143,7 +135,7 @@ export const serializerCompiler: FastifySerializerCompiler<ZodAny | { properties
       return JSON.stringify(result.data);
     }
 
-    throw new ResponseValidationError(result);
+    throw new ResponseValidationError(result, method, url);
   };
 
 /**

test/__snapshots__/fastify-swagger.spec.ts.snap

@@ -1,6 +1,6 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
-exports[`transformer generates types for fastify-swagger correctly 1`] = `
+exports[`transformer > generates types for fastify-swagger correctly 1`] = `
 {
   "components": {
     "schemas": {},
@@ -123,7 +123,7 @@ exports[`transformer generates types for fastify-swagger correctly 1`] = `
 }
 `;
 
-exports[`transformer should not generate ref 1`] = `
+exports[`transformer > should not generate ref 1`] = `
 {
   "components": {
     "schemas": {},

test/request-schema.spec.ts

@@ -73,6 +73,23 @@ describe('response schema', () => {
     const response = await app.inject().get('/');
 
     expect(response.statusCode).toBe(400);
-    expect(response.json()).toMatchSnapshot();
+    expect(response.json()).toMatchInlineSnapshot(`
+      {
+        "code": "FST_ERR_VALIDATION",
+        "error": "Bad Request",
+        "message": "[
+        {
+          "code": "invalid_type",
+          "expected": "string",
+          "received": "undefined",
+          "path": [
+            "name"
+          ],
+          "message": "Required"
+        }
+      ]",
+        "statusCode": 400,
+      }
+    `);
   });
 });

test/response-schema.spec.ts

@@ -4,6 +4,7 @@ import { z } from 'zod';
 
 import type { ZodTypeProvider } from '../src';
 import { serializerCompiler, validatorCompiler } from '../src';
+import type { ResponseValidationError } from '../src/ResponseValidationError';
 
 describe('response schema', () => {
   describe('does not fail on empty response schema (204)', () => {
@@ -37,10 +38,19 @@ describe('response schema', () => {
               },
             },
             handler: (req, res) => {
+              // @ts-expect-error
               res.status(204).send({ id: 1 });
             },
           });
       });
+      app.setErrorHandler((err, req, reply) => {
+        return reply.code(500).send({
+          error: 'Internal Server Error',
+          message: "Response doesn't match the schema",
+          details: (err as unknown as ResponseValidationError).details,
+          statusCode: 500,
+        });
+      });
       await app.ready();
     });
 
@@ -59,11 +69,26 @@ describe('response schema', () => {
       const response = await app.inject().get('/incorrect');
 
       expect(response.statusCode).toBe(500);
-      expect(response.json()).toEqual({
-        error: 'Internal Server Error',
-        message: "Response doesn't match the schema",
-        statusCode: 500,
-      });
+      expect(response.json()).toMatchInlineSnapshot(`
+        {
+          "details": {
+            "error": [
+              {
+                "code": "invalid_type",
+                "expected": "undefined",
+                "message": "Expected undefined, received object",
+                "path": [],
+                "received": "object",
+              },
+            ],
+            "method": "GET",
+            "url": "/incorrect",
+          },
+          "error": "Internal Server Error",
+          "message": "Response doesn't match the schema",
+          "statusCode": 500,
+        }
+      `);
     });
   });
 
@@ -123,7 +148,9 @@ describe('response schema', () => {
       const response = await app.inject().get('/incorrect');
 
       expect(response.statusCode).toBe(500);
-      expect(response.body).toMatchSnapshot();
+      expect(response.body).toMatchInlineSnapshot(
+        `"{"statusCode":500,"error":"Internal Server Error","message":"Response doesn't match the schema"}"`,
+      );
     });
   });
 
@@ -189,7 +216,7 @@ describe('response schema', () => {
       const response = await app.inject().get('/incorrect');
 
       expect(response.statusCode).toBe(500);
-      expect(response.json()).toMatchSnapshot();
+      expect(response.json()).toMatchInlineSnapshot();
     });
   });
 });

tsconfig.json

@@ -4,9 +4,10 @@
     "rootDir": "src",
     "outDir": "dist",
     "esModuleInterop": true,
+    "skipLibCheck": true,
     "moduleResolution": "Node",
     "module": "CommonJS",
     "target": "ES2020"
   },
-  "exclude": ["./node_modules", "types/**/*.test-d.ts", "test", "dist"]
+  "exclude": ["./node_modules", "types/**/*.test-d.ts", "test", "dist", "vitest.config.mts"]
 }

vitest.config.mts

@@ -0,0 +1,23 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    globals: true,
+    watch: false,
+    environment: 'node',
+    reporters: ['verbose'],
+    coverage: {
+      provider: 'v8',
+      include: ['src/**/*.ts'],
+      exclude: ['test/**/*.ts'],
+      reporter: ['text', 'lcov'],
+      all: true,
+      thresholds: {
+        statements: 95,
+        branches: 90,
+        functions: 100,
+        lines: 95,
+      },
+    },
+  },
+});