Remove support for the esm package

Author: novemberborn

docs/recipes/es-modules.md

@@ -6,7 +6,9 @@ As of Node.js 12.17, [ECMAScript Modules](https://nodejs.org/docs/latest/api/esm
 
 ## Using the `esm` package
 
-If you want to use the ESM syntax, without relying on Node.js' implementation, your best bet is to use the [`esm`](https://github.com/standard-things/esm) package. Make sure to use the `.js` extension and *do not* set `"type": "module"` in `package.json`.
+If you're using Node.js 10 and AVA 3 and you want to use the ESM syntax, without relying on Node.js' implementation, your best bet is to use the [`esm`](https://github.com/standard-things/esm) package. Make sure to use the `.js` extension and *do not* set `"type": "module"` in `package.json`.
+
+*Note: The `esm` package is no longer supported in AVA 4.*
 
 Here's how you get it working with AVA.
 

lib/reporters/beautify-stack.js

@@ -9,7 +9,6 @@ const stackUtils = new StackUtils({
 		'append-transform',
 		'ava',
 		'empower-core',
-		'esm',
 		'nyc'
 	],
 	internals: [

lib/serialize-error.js

@@ -127,11 +127,8 @@ function trySerializeError(error, shouldBeautifyStack, testFile) {
 
 			retval.summary = retval.summary.trim();
 		} else {
-			// Skip the source line header inserted by `esm`:
-			// <https://github.com/standard-things/esm/wiki/improved-errors>
-			const start = lines.findIndex(line => !/:\d+$/.test(line));
 			retval.summary = '';
-			for (let index = start; index < lines.length; index++) {
+			for (let index = 0; index < lines.length; index++) {
 				if (lines[index].startsWith('    at')) {
 					break;
 				}

lib/worker/subprocess.js

@@ -174,7 +174,6 @@ ipc.options.then(async options => {
 		return null;
 	}).filter(provider => provider !== null);
 
-	let requireFn = require;
 	const load = async ref => {
 		for (const extension of extensionsToLoadAsModules) {
 			if (ref.endsWith(`.${extension}`)) {
@@ -184,22 +183,16 @@ ipc.options.then(async options => {
 
 		for (const provider of providers) {
 			if (provider.canLoad(ref)) {
-				return provider.load(ref, {requireFn});
+				return provider.load(ref, {requireFn: require});
 			}
 		}
 
-		return requireFn(ref);
+		return require(ref);
 	};
 
 	try {
 		for await (const ref of (options.require || [])) {
-			const mod = await load(ref);
-
-			try {
-				if (Reflect.has(mod, Symbol.for('esm:package'))) {
-					requireFn = mod(module);
-				}
-			} catch {}
+			await load(ref);
 		}
 
 		// Install dependency tracker after the require configuration has been evaluated

package-lock.json

@@ -122,7 +122,6 @@
 		"ansi-escapes": "^4.3.1",
 		"c8": "^7.5.0",
 		"delay": "^5.0.0",
-		"esm": "^3.2.25",
 		"execa": "^5.0.0",
 		"fs-extra": "^9.1.0",
 		"get-stream": "^6.0.0",

package.json

@@ -665,14 +665,3 @@ test('using --match with matching tests will only report those passing tests', t
 		t.is(runStatus.stats.passedTests, 1);
 	});
 });
-
-test('`esm` package support', t => {
-	const api = apiCreator({
-		require: [require.resolve('esm')]
-	});
-
-	return api.run({files: [path.join(__dirname, 'fixture/userland-esm-package/test.js')]})
-		.then(runStatus => {
-			t.is(runStatus.stats.passedTests, 1);
-		});
-});

test-tap/api.js

@@ -96,13 +96,3 @@ test('creates multiline summaries for syntax errors', t => {
 	t.is(serializedError.summary, 'Hello\nThere\nSyntaxError here');
 	t.end();
 });
-
-test('skips esm enhancement lines when finding the summary', t => {
-	const error = new Error();
-	Object.defineProperty(error, 'stack', {
-		value: 'file://file.js:1\nFirst line\nSecond line'
-	});
-	const serializedError = serialize(error);
-	t.is(serializedError.summary, 'First line\nSecond line');
-	t.end();
-});