CodeCoverage

To generate a code coverage report using the c8 tool, include the -C (or --coverage) option when running tests via a CLI command extest run-tests or extest setup-and-run.

Configuration Options

A configuration file can change the default behaviors of the c8 tool. The framework searches for c8 JSON configuration files named .c8rc, .c8rc.json, .nycrc, or .nycrc.json, starting from the root of your project and walking up the filesystem tree. You can check out what options are supported in the c8 documentation.

If no c8 JSON configuration file is provided, the following default values will be used:

const reportOptions: any = {
  reporter: ["text", "html"],
  all: false,
  excludeNodeModules: true,
  include: [],
  exclude: [
    "coverage/**",
    "packages/*/test{,s}/**",
    "**/*.d.ts",
    "test{,s}/**",
    "test{,-*}.{js,cjs,mjs,ts,tsx,jsx}",
    "**/*{.,-}test.{js,cjs,mjs,ts,tsx,jsx}",
    "**/__tests__/**",
    "**/{ava,babel,nyc}.config.{js,cjs,mjs}",
    "**/jest.config.{js,cjs,mjs,ts}",
    "**/{karma,rollup,webpack}.config.js",
    "**/.{eslint,mocha}rc.{js,cjs}",
  ],
  extension: [".js", ".cjs", ".mjs", ".ts", ".tsx", ".jsx"],
  excludeAfterRemap: false,
  skipFull: false,
  tempDirectory: this.targetDir,
  resolve: "",
  omitRelative: true,
  allowExternal: false,
};

where this.targetDir is a directory created under the temporary directory specified with the TMP enviornment variable and coverage reports are saved under ./coverage, where the c8 tool stores outputs by default.

Notes on loading source files when code coverage is enabled

With code coverage enabled, there's no need to build a vsix file as sources will be loaded directly from your project directory during testing. By default the framework does not build or install a vsix file when code coverage enabled by the CLI -C (or --coverage) option.

However, in special situations where you need to load a vsix file in your test, for example, when you need to test the Extensions SideBar for installed extensions, add the -u (or --uninstall_extension) option.

When -u option is specified, the framework will build and install a vsix file prior to executing tests. After completing the test run, the framework uninstall the vsix file. Keep in mind that even when using the -u option, source codes will still be sourced directly from your project directory with code coverage enabled.