test: use sourcemaps in unit tests (#6485)

Introduce the source-map-support package and require it for mocha running unit tests.

Turn on the sourceMap option for tsconfig.base.json so that the sourceMappingURL= line is emitted in the generated files.

Co-authored-by: Mathias Bynens <mathias@qiwi.be>

mocha-config/puppeteer-unit-tests.js

@@ -18,7 +18,11 @@ const base = require('./base');
 
 module.exports = {
   ...base,
-  require: ['./test/mocha-ts-require', './test/mocha-utils.ts'],
+  require: [
+    './test/mocha-ts-require',
+    './test/mocha-utils.ts',
+    'source-map-support/register',
+  ],
   spec: 'test/*.spec.ts',
   extension: ['js', 'ts'],
   retries: process.env.CI ? 2 : 0,

package.json

@@ -96,6 +96,7 @@
     "pngjs": "^5.0.0",
     "prettier": "^2.1.2",
     "sinon": "^9.0.2",
+    "source-map-support": "^0.5.19",
     "standard-version": "^9.0.0",
     "text-diff": "^1.0.1",
     "ts-node": "^9.0.0",

tsconfig.base.json

@@ -8,6 +8,7 @@
     "module": "ESNext",
     "declaration": true,
     "declarationMap": true,
-    "resolveJsonModule": true
+    "resolveJsonModule": true,
+    "sourceMap": true,
   }
 }