jest_typescript_integration

Jest Typscript Integration Example

Detailed documentation on the Jest integration is available in the main Jazzer.js documentation.

Quickstart

To use the Jest integration install the @jazzer.js/jest-runner and ts-jest packages then configure jest-runner as a dedicated test runner in package.json or jest.config.{ts|js}.

The example below shows how to configure the Jazzer.js Jest integration in combination with the normal Jest runner.

  "jest": {
    "projects": [
      {
        "displayName": "Jest",
        "preset": "ts-jest",
      },
      {
        "displayName": {
          "name": "Jazzer.js",
          "color": "cyan",
        },
        "preset": "ts-jest",
        "runner": "@jazzer.js/jest-runner",
        "testEnvironment": "node",
        "testMatch": ["<rootDir>/*.fuzz.[jt]s"],
      },
    ],
    "coveragePathIgnorePatterns": ["/node_modules/", "/dist/"],
    "modulePathIgnorePatterns": ["/node_modules", "/dist/"],
  }

Further configuration can be specified in .jazzerjsrc, like in any other project, in the following format:

{
	"includes": ["*"],
	"excludes": ["node_modules"],
    [...]
}

Write a Jest fuzz test like:

// file: jazzerjs.fuzz.ts
import "@jazzer.js/jest-runner/jest-extension";
describe("My describe", () => {
	it.fuzz("My fuzz test", (data: Buffer) => {
		target.fuzzMe(data);
	});
});

Note: the import statement extends jest's It interface to include the fuzz property and is necessary for TypeScript to compile the test file.