How do you use Istanbul Code Coverage with transpiled Typescript?

Question

I\'ve been reading articles on this all morning trying to get my environment setup correctly. But for some reason I\'m not getting it. My setup-

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Answer 1

As blakeembrey mentioned. Istanbul 1.x handles it well.

Below an example of pure npm script that does it with Jasmine.

See https://github.com/Izhaki/Typescript-Jasmine-Istanbul-Boilerplate.

package.json (the relevant stuff)

{
  "scripts": {
    "postinstall": "typings install dt~jasmine --save --global",
    "test": "ts-node node_modules/.bin/jasmine JASMINE_CONFIG_PATH=jasmine.json",
    "test:coverage": "ts-node node_modules/istanbul/lib/cli.js cover -e .ts  -x \"*.d.ts\" -x \"*.spec.ts\" node_modules/jasmine/bin/jasmine.js -- JASMINE_CONFIG_PATH=jasmine.json"
  },
  "devDependencies": {
    "istanbul": "^1.1.0-alpha.1",
    "jasmine": "^2.4.1",
    "ts-node": "^0.9.3",
    "typescript": "^1.8.10",
    "typings": "^1.3.1"
  },
}

Output

Answer 2

TL;DR: There is a tool: https://github.com/SitePen/remap-istanbul described as A tool for remapping Istanbul coverage via Source Maps

The article on Sitepan describes it in more detail:

Intern as well as other JavaScript testing frameworks utilise Istanbul for their code coverage analysis. As we started to adopt more and more TypeScript for our own projects, we continued to struggle with getting a clear picture of our code coverage as all the reports only included the coverage of our emitted code. We had to try to use the compilers in our minds to try to figure out where we were missing test coverage. We also like to set metrics around our coverage to let us track if we are headed the right direction.

A couple of us started exploring how we might be able to accomplish mapping the coverage report back to its origins and after a bit of work, we created remap-istanbul, a package that allows Istanbul coverage information to be mapped back to its source when there are Source Maps available. While we have been focused on TypeScript, it can be used wherever the coverage is being produced on emitted code, including the tools mentioned above!

How to use the tool with gulp: https://github.com/SitePen/remap-istanbul#gulp-plugin

Answer 3

This is repo works. I ran the repo and can see the tests running. Html view is also generated. https://github.com/Izhaki/Typescript-Jasmine-Istanbul-Boilerplate

Answer 4

None of the examples provided worked for my Node.JS project (written in TypeScript). I wanted to run unit tests in Jasmine, and covered by Istanbul.

I ended up getting it working with the following.

package.json:

{
  "scripts": {
    "lint": "tslint 'src/**/*.ts'",
    "remap": "./node_modules/.bin/remap-istanbul -i ./coverage/coverage-final.json -t html -o ./coverage && rimraf ./coverage/dist",
    "test": "npm run lint && rimraf dist coverage && tsc --project tsconfig-test.json && ./node_modules/.bin/istanbul cover ./node_modules/.bin/jasmine JASMINE_CONFIG_PATH=jasmine.json && npm run remap"
  },
  "devDependencies": {
    "@types/jasmine": "2.8.6",
    "@types/node": "9.6.6",
    "istanbul": "0.4.5",
    "jasmine": "3.1.0",
    "remap-istanbul": "0.11.1",
    "rimraf": "2.6.2",
    "tslint": "5.9.1",
    "typescript": "2.8.1"
  }
}

jasmine.json

{
  "spec_dir": "dist",
  "spec_files": [
    "**/*.spec.js"
  ],
  "stopSpecOnExpectationFailure": false,
  "random": false
}

.istanbul.yml

instrumentation:
  root: ./dist
  excludes: ['**/*.spec.js', '**/fixtures/*.js']
  include-all-sources: true
reporting:
  reports:
    - html
    - json
    - text-summary
  dir: ./coverage

tsconfig-test.json

{
  "compilerOptions": {
    "declaration": true,
    "lib": [
      "dom",
      "es6"
    ],
    "module": "commonjs",
    "noImplicitAny": true,
    "outDir": "dist",
    "sourceMap": true,
    "target": "es5"
  },
  "include": [
    "src/**/*.ts"
  ],
  "exclude": [
    "node_modules"
  ]
}

Answer 5

If you want source map support with Istanbul, you can use the 1.0 alpha release as the current release does not support source maps. I have it set up using ts-node in http://github.com/typings/typings (see https://github.com/typings/typings/blob/bff1abad91dabec1cd8a744e0dd3f54b613830b5/package.json#L19) and source code is being mapped. It looks great and is nice to have my tests and code coverage all running in-process with zero transpilation. Of course, you can use Istanbul 1.0 with the transpiled JavaScript.

For the browser implementation you're using, I'd have to see more of code of what you're doing to see this'll just work for you, but try the 1.0.0-alpha.2 and see what happens.