feat: support pnpm's publishConfig (#120)

* feat: prefer publish config when defined

* refactor: apply suggestion

Co-authored-by: Hiroki Osame <hiroki.osame@gmail.com>

* fix(lint): remove trailing spaces

* readme

* tests

---------

Co-authored-by: Hiroki Osame <hiroki.osame@gmail.com>

Author: kwaa

README.md

@@ -287,6 +287,17 @@ Or to inline them in the distribution files:
 pkgroll --sourcemap=inline
 ```
 
+## Dev vs Prod config
+
+In some cases, it makes sense to use different `package.json` field values for the published environment. You can achieve this by using the [`publishConfig`](https://pnpm.io/package_json#publishconfig) field (extended by pnpm). This allows you to override specific fields during publication with a clean separation of concerns.
+
+The following fields can be overridden using `publishConfig`:
+- `bin`
+- `main`
+- `exports`
+- `types`
+- `module`
+
 ## FAQ
 
 ### Why bundle with Rollup?

src/utils/parse-package-json/get-export-entries.ts

@@ -142,12 +142,35 @@ const addExportPath = (
 	}
 };
 
-export const getExportEntries = (packageJson: PackageJson) => {
+export const getExportEntries = (
+	_packageJson: Readonly<PackageJson>,
+) => {
+	const packageJson = { ..._packageJson };
+
+	// Prefer publishConfig when defined
+	// https://pnpm.io/package_json#publishconfig
+	const { publishConfig } = packageJson;
+	if (publishConfig) {
+		const fields = [
+			'bin',
+			'main',
+			'exports',
+			'types',
+			'module',
+		];
+
+		for (const field of fields) {
+			if (publishConfig[field]) {
+				packageJson[field] = publishConfig[field];
+			}
+		}
+	}
+
 	const exportEntriesMap: Record<string, ExportEntry> = {};
 	const packageType = packageJson.type ?? 'commonjs';
 
-	if (packageJson.main) {
-		const mainPath = packageJson.main;
+	const mainPath = packageJson.main;
+	if (mainPath) {
 		addExportPath(exportEntriesMap, {
 			outputPath: mainPath,
 			type: getFileType(mainPath) ?? packageType,
@@ -174,9 +197,8 @@ export const getExportEntries = (packageJson: PackageJson) => {
 		});
 	}
 
-	if (packageJson.bin) {
-		const { bin } = packageJson;
-
+	const { bin } = packageJson;
+	if (bin) {
 		if (typeof bin === 'string') {
 			addExportPath(exportEntriesMap, {
 				outputPath: bin,

tests/specs/builds/bin.ts

@@ -79,5 +79,27 @@ export default testSuite(({ describe }, nodePath: string) => {
 			const content = await fixture.readFile('dist/dynamic-require.mjs', 'utf8');
 			expect(content.startsWith('#!/usr/bin/env node')).toBeTruthy();
 		});
+
+		test('publishConfig', async () => {
+			await using fixture = await createFixture({
+				...packageFixture(),
+				'package.json': createPackageJson({
+					bin: './dist/invalid.mjs',
+					publishConfig: {
+						bin: './dist/index.mjs',
+					},
+				}),
+			});
+
+			const pkgrollProcess = await pkgroll([], {
+				cwd: fixture.path,
+				nodePath,
+			});
+
+			expect(pkgrollProcess.exitCode).toBe(0);
+			expect(pkgrollProcess.stderr).toBe('');
+
+			expect(await fixture.exists('dist/index.mjs')).toBe(true);
+		});
 	});
 });

tests/specs/builds/package-exports.ts

@@ -207,5 +207,28 @@ export default testSuite(({ describe }, nodePath: string) => {
 			await fixture.exists('dist/nested/index.node.js');
 			await fixture.exists('dist/nested/index.node.d.ts');
 		});
+
+		test('publishConfig', async () => {
+			await using fixture = await createFixture({
+				...packageFixture(),
+				'package.json': createPackageJson({
+					exports: './dist/invalid.js',
+					publishConfig: {
+						exports: './dist/index.js',
+					},
+				}),
+			});
+
+			const pkgrollProcess = await pkgroll([], {
+				cwd: fixture.path,
+				nodePath,
+			});
+
+			expect(pkgrollProcess.exitCode).toBe(0);
+			expect(pkgrollProcess.stderr).toBe('');
+
+			const content = await fixture.readFile('dist/index.js', 'utf8');
+			expect(content).toMatch('module.exports =');
+		});
 	});
 });