t2ym/web-component-tester-istanbul

Instanbul coverage reporting for projects being tested by web-component-tester

wct-istanbul

A fork of web-component-tester-istanbul Istanbul coverage plugin for web-component-tester@^6.6.0.

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

Supported syntax

Syntax	Status
ES2015+	✅
ES Modules	✅
object rest/spread properties	✅
async/await	✅
import.meta	✅
async iterator	✅

Notes

• babel-plugin-istanbul and IstanbulJS libraries compatible with nyc v11.0.3 are used since wct-istanbul 0.14.0.
• Only global coverage thresholds are effective since wct-istanbul 0.12.0.

Installation

npm install --save-dev wct-istanbul

Basic Usage

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

Example

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

Options

Below are the available configuration options:

dir

The directory to write coverage reports to.

reporters

An array of istanbul reporters to use.

include

Files to include in instrumentation.

exclude

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

Coverage Thresholds

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

Example

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
        }
      }
    }
  }
}