Replace Travis CI with Github Actions

... and replace mocha+istanbul with built-in "node:test" module and rely
on the --experimental-test-coverage option.

Although not used anywhere, include an example with genhtml (part of
GCC's lcov package) in case someone is interested in locally viewing the
coverage data in HTML format.

.github/workflows/run-tests.yaml

@@ -0,0 +1,92 @@
+on: [ push, pull_request ]
+
+name: Tests
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-node@v4
+    - run: npm install # install eslint
+    - run: npm run lint
+
+  test-old-node:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node_version: [ 6.4.0 ]
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Use Node.js ${{ matrix.node_version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node_version }}
+        cache: npm
+
+    # Note: no npm ci / npm install:
+    # The package has no non-dev dependencies.
+    # Old Node.js does not have built-in coverage reporting, so we use packages from before.
+    # - run: npm install [email protected] # TODO: can be removed? Not needed with github action?
+    - run: npm install [email protected]
+    - run: npm install [email protected]
+
+    # test-coverage will also run the tests, but does not print helpful output upon test failure.
+    # So we also run the tests separately.
+    - run: ./node_modules/.bin/mocha ./test.js --reporter spec
+    # ^ instead of: npm test
+
+    - run: ./node_modules/.bin/istanbul cover ./node_modules/.bin/mocha -- --reporter spec # creates coverage/lcov.info
+    # ^ instead of: npm run test-coverage
+
+    - name: Send coverage for Node ${{ matrix.node_version }} to Coveralls
+      uses: coverallsapp/github-action@v2
+      with:
+        parallel: true
+        file: coverage/lcov.info
+        flag-name: coverage-node-${{ matrix.node_version }}
+
+  test-recent-node:
+    name: Build
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node_version: [ 18, 20 ]
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Use Node.js ${{ matrix.node_version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node_version }}
+        cache: npm
+
+    # Note: no npm ci / npm install:
+    # The package has no non-dev dependencies.
+    # We rely on Node.js's built-in test module and reporter,
+    # and do not require any dev dependencies either.
+
+    # test-coverage will also run the tests, but does not print helpful output upon test failure.
+    # So we also run the tests separately.
+    - run: npm test
+
+     # note: --experimental-test-coverage requires Node v18.15.0+
+    - run: npm run test-coverage
+
+    - name: Send coverage for Node ${{ matrix.node_version }} to Coveralls
+      uses: coverallsapp/github-action@v2
+      with:
+        parallel: true
+        file: lcov.info
+        flag-name: coverage-node-${{ matrix.node_version }}
+
+  coveralls:
+    needs: [ test-old-node, test-recent-node ]
+    if: ${{ always() }}
+    runs-on: ubuntu-latest
+    steps:
+    - name: Report to Coveralls
+      uses: coverallsapp/github-action@v2
+      with:
+        parallel-finished: true

.gitignore

@@ -1,3 +1,4 @@
 *.swp
 coverage/
+lcov.info
 node_modules/

README.md

@@ -1,6 +1,6 @@
 # proxy-from-env
 
-[![Build Status](https://travis-ci.org/Rob--W/proxy-from-env.svg?branch=master)](https://travis-ci.org/Rob--W/proxy-from-env)
+![Build Status](https://github.com/Rob--W/proxy-from-env/actions/workflows/run-tests.yaml/badge.svg?branch=master)
 [![Coverage Status](https://coveralls.io/repos/github/Rob--W/proxy-from-env/badge.svg?branch=master)](https://coveralls.io/github/Rob--W/proxy-from-env?branch=master)
 
 `proxy-from-env` is a Node.js package that exports a function (`getProxyForUrl`)

package.json

@@ -5,8 +5,9 @@
   "main": "index.js",
   "scripts": {
     "lint": "eslint *.js",
-    "test": "mocha ./test.js --reporter spec",
-    "test-coverage": "istanbul cover ./node_modules/.bin/_mocha -- --reporter spec"
+    "test": "node --test ./test.js",
+    "test-coverage": "node --experimental-test-coverage --test-reporter=lcov --test-reporter-destination=lcov.info ./test.js",
+    "test-coverage-as-html": "npm run test-gen-lcov && genhtml lcov.info -o coverage/"
   },
   "repository": {
     "type": "git",
@@ -26,9 +27,6 @@
   },
   "homepage": "https://github.com/Rob--W/proxy-from-env#readme",
   "devDependencies": {
-    "coveralls": "^3.0.9",
-    "eslint": "^6.8.0",
-    "istanbul": "^0.4.5",
-    "mocha": "^7.1.0"
+    "eslint": "^6.8.0"
   }
 }

test.js

@@ -1,6 +1,13 @@
 /* eslint max-statements:0 */
 'use strict';
 
+// For compatibility with old Node that
+// The node:test modules is only supported in Node v16.17.0+.
+// To run in earlier versions, run this file through mocha instead,
+// e.g. mocha ./test.js --reporter spec
+var describe = global.describe || require('node:test').describe;
+var it = global.it || require('node:test').it;
+
 var assert = require('assert');
 var parseUrl = require('url').parse;