test: env applied in node_modules

Author: privatenumber

tests/fixtures.ts

@@ -57,6 +57,7 @@ export const fixtureFiles = {
 	if (
 		process.env.NODE_ENV === 'production'
 		|| process.env['NODE_ENV'] === 'production'
+		|| process.env['PROD'] === 'true'
 	) {
 		console.log('production');
 		require('./cjs.cjs');

tests/specs/builds/env.ts

@@ -13,7 +13,7 @@ export default testSuite(({ describe }, nodePath: string) => {
 				}),
 			});
 
-			const pkgrollProcess = await pkgroll(['--env.NODE_ENV=development'], {
+			const pkgrollProcess = await pkgroll(['--env.NODE_ENV=development', '--env.PROD=false'], {
 				cwd: fixture.path,
 				nodePath,
 			});
@@ -25,5 +25,42 @@ export default testSuite(({ describe }, nodePath: string) => {
 			expect(content).toMatch('development');
 			expect(content).not.toMatch('production');
 		});
+
+		test('dead code elimination via env in node_modules', async () => {
+			await using fixture = await createFixture({
+				'package.json': createPackageJson({
+					main: './dist/index.mjs',
+				}),
+				'src/index.mjs': 'import "dep"',
+				'node_modules/dep': {
+					'package.json': createPackageJson({
+						main: 'index.js',
+					}),
+					'index.js': `
+					if (
+						process.env.NODE_ENV === 'production'
+						|| process.env['NODE_ENV'] === 'production'
+						|| process.env['PROD'] === 'true'
+					) {
+						console.log('production');
+					} else {
+						console.log('development');
+					}
+					`,
+				},
+			});
+
+			const pkgrollProcess = await pkgroll(['--env.NODE_ENV=development', '--env.PROD=false'], {
+				cwd: fixture.path,
+				nodePath,
+			});
+
+			expect(pkgrollProcess.exitCode).toBe(0);
+			expect(pkgrollProcess.stderr).toBe('');
+
+			const content = await fixture.readFile('dist/index.mjs', 'utf8');
+			expect(content).toMatch('development');
+			expect(content).not.toMatch('production');
+		});
 	});
 });