Sanitize stderr before checking output

test/cli/samples/empty-chunk-multiple/_config.js

@@ -1,13 +1,9 @@
-const assert = require('assert');
+const { assertStderrIncludes } = require('../../../utils.js');
 
 module.exports = {
 	solo: true,
 	description: 'shows warning when multiple chunks empty',
 	command: 'rollup -c',
 	error: () => true,
-	stderr: stderr => {
-		console.log(JSON.stringify(stderr));
-		assert.ok(stderr.includes('(!) Generated empty chunks'));
-		assert.ok(stderr.includes('a, b'));
-	}
+	stderr: stderr => assertStderrIncludes(stderr, '(!) Generated empty chunks\na, b')
 };

test/cli/samples/empty-chunk/_config.js

@@ -1,13 +1,9 @@
-const assert = require('assert');
+const { assertStderrIncludes } = require('../../../utils.js');
 
 module.exports = {
 	solo: true,
 	description: 'shows warning when chunk empty',
 	command: 'rollup -c',
 	error: () => true,
-	stderr: stderr => {
-		console.log(JSON.stringify(stderr));
-		assert.ok(stderr.includes('(!) Generated an empty chunk'));
-		assert.ok(stderr.includes('main'));
-	}
+	stderr: stderr => assertStderrIncludes(stderr, '(!) Generated an empty chunk\nmain')
 };

test/utils.js

@@ -12,6 +12,7 @@ exports.loader = loader;
 exports.normaliseOutput = normaliseOutput;
 exports.runTestSuiteWithSamples = runTestSuiteWithSamples;
 exports.assertDirectoriesAreEqual = assertDirectoriesAreEqual;
+exports.assertStderrIncludes = assertStderrIncludes;
 
 function normaliseError(error) {
 	delete error.stack;
@@ -224,3 +225,12 @@ function assertFilesAreEqual(actualFiles, expectedFiles, dirs = []) {
 		);
 	});
 }
+
+function assertStderrIncludes(stderr, expected) {
+	// eslint-disable-next-line no-control-regex
+	const output = stderr.replace(/\x1b\[[^m]*m/g, '');
+	assert.ok(
+		output.includes(expected),
+		`Could not find ${JSON.stringify(expected)} in ${JSON.stringify(output)}`
+	);
+}