Istanbul coverage plugin for web-component-tester.

Use this plugin to collect and report test coverage (via istanbul) for your project on each test run.

npm install web-component-tester-istanbul --save-dev

Add the following configuration to web-component-tester's config file.

module.exports = {
  plugins: {
    istanbul: {
      dir: "./coverage",
      reporters: ["text-summary", "lcov"],
      include: [
        "**/*.js"
      ],
      exclude: [
        "polymer/polymer.js",
        "platform/platform.js"
      ]
    }
  }
}

Below are the available configuration options:

The directory to write coverage reports to.

An array of istanbul reporters to use.

Files to include in instrumentation.

Files to exclude from instrumentation (this trumps files 'included' with the option above).

In addition to measuring coverage, this plugin can be used to enforce coverage thresholds. If coverage does not meet the configured thresholds, then the test run will fail, even if all tests passed.

This requires specifying the thresholds option for the plugin

The following configuration will cause the test run to fail if less than 100% of the statements in instrumented files are covered by tests.

module.exports = {
  plugins: {
    istanbul: {
      dir: "./coverage",
      reporters: ["text-summary", "lcov"],
      include: [
        "**/*.js"
      ],
      exclude: [
        "polymer/polymer.js",
        "platform/platform.js"
      ],
      thresholds: {
        global: {
          statements: 100
        }
      }
    }
  }
}