Fix coverage-gathering for the reference implementation

This has been broken for a while. By switching from nyc/istanbul to c8 and doing some browserify tricks, it now works.

Author: MattiasBuelens

reference-implementation/.eslintignore

@@ -1,3 +1,4 @@
 web-platform-tests/
 coverage/
 generated/
+bundle.js

reference-implementation/.gitignore

@@ -5,3 +5,4 @@ package-lock.json
 .nyc_output/
 coverage/
 generated/
+bundle.js

reference-implementation/package.json

@@ -2,28 +2,23 @@
   "private": true,
   "description": "Reference implementation and tests for the WHATWG Streams Standard",
   "scripts": {
-    "pretest": "node compile-idl.js",
+    "pretest": "node compile-idl.js && browserify lib/index.js -d -o bundle.js",
     "test": "npm run lint && npm run wpt",
     "wpt": "npm run pretest && node --expose_gc run-web-platform-tests.js",
     "sync-wpt": "git submodule update --init",
     "lint": "eslint .",
-    "coverage": "nyc --reporter=lcov npm test && opener coverage/lcov-report/index.html"
+    "coverage": "c8 --reporter=lcov -- npm run wpt && opener coverage/lcov-report/index.html"
   },
   "author": "Domenic Denicola <[email protected]> (https://domenic.me/)",
   "license": "(CC0-1.0 OR MIT)",
   "devDependencies": {
     "browserify": "^16.5.1",
+    "c8": "^7.7.2",
     "debug": "^4.1.1",
     "eslint": "^6.8.0",
     "minimatch": "^3.0.4",
-    "nyc": "^15.0.1",
     "opener": "^1.5.1",
     "webidl2js": "^16.2.0",
     "wpt-runner": "^3.2.1"
-  },
-  "nyc": {
-    "include": [
-      "**/lib/**/*.js"
-    ]
   }
 }

reference-implementation/run-web-platform-tests.js

@@ -5,7 +5,6 @@
 const path = require('path');
 const fs = require('fs');
 const { promisify } = require('util');
-const browserify = require('browserify');
 const wptRunner = require('wpt-runner');
 const minimatch = require('minimatch');
 const readFileAsync = promisify(fs.readFile);
@@ -28,7 +27,7 @@ main().catch(e => {
 });
 
 async function main() {
-  const entryPath = path.resolve(__dirname, 'lib/index.js');
+  const bundlePath = path.resolve(__dirname, 'bundle.js');
   const wptPath = path.resolve(__dirname, 'web-platform-tests');
   const testsPath = path.resolve(wptPath, 'streams');
 
@@ -40,7 +39,8 @@ async function main() {
   ];
   const anyTestPattern = /\.any\.html$/;
 
-  const bundledJS = await bundle(entryPath);
+  let bundledJS = await readFileAsync(bundlePath, { encoding: 'utf8' });
+  bundledJS = `${bundledJS}\n//# sourceURL=file://${bundlePath}`;
 
   const failures = await wptRunner(testsPath, {
     rootURL: 'streams/',
@@ -83,9 +83,3 @@ async function main() {
     }
   }
 }
-
-async function bundle(entryPath) {
-  const b = browserify([entryPath]);
-  const buffer = await promisify(b.bundle.bind(b))();
-  return buffer.toString();
-}