support @std/esm (#1618)

* support @std/esm

* fix path test for windows

* fix linter error

* Stricter regex. Use shorthand .esmrc file in fixture.

* update package-lock.json

lib/test-worker.js

@@ -27,7 +27,13 @@ globals.options = opts;
 
 const serializeError = require('./serialize-error');
 
-(opts.require || []).forEach(x => require(x));
+(opts.require || []).forEach(x => {
+	if (/[/\\]@std[/\\]esm[/\\]index\.js$/.test(x)) {
+		require = require(x)(module); // eslint-disable-line no-global-assign
+	} else {
+		require(x);
+	}
+});
 
 adapter.installSourceMapSupport();
 adapter.installPrecompilerHook();

package.json

@@ -146,6 +146,7 @@
 		"update-notifier": "^2.3.0"
 	},
 	"devDependencies": {
+		"@std/esm": "^0.19.1",
 		"cli-table2": "^0.2.0",
 		"codecov": "^3.0.0",
 		"del": "^3.0.0",

test/fixture/std-esm/.esmrc

@@ -0,0 +1,3 @@
+{
+	"esm": "cjs"
+}

test/fixture/std-esm/index.js

@@ -0,0 +1 @@
+export default 'foo';

test/fixture/std-esm/test.js

@@ -0,0 +1,6 @@
+import test from '../../../';
+import m from '.';
+
+test('works', t => {
+	t.is(m, 'foo');
+});

test/fork.js

@@ -135,6 +135,17 @@ test('babelrc is ignored', t => {
 		});
 });
 
+test('@std/esm support', t => {
+	return fork(fixture('std-esm/test.js'), {
+		require: [require.resolve('@std/esm')]
+	})
+		.run({})
+		.then(info => {
+			t.is(info.stats.passCount, 1);
+			t.end();
+		});
+});
+
 // TODO: Skipped until we can do this properly in #1455
 test('color support is initialized correctly', t => {
 	t.plan(1);