Implement subpath exports

package.json

@@ -54,6 +54,7 @@
 		"@rollup/plugin-replace": "^5.0.7",
 		"@rollup/pluginutils": "^5.1.0",
 		"esbuild": "^0.23.0",
+		"glob": "^11.0.0",
 		"magic-string": "^0.30.10",
 		"rollup": "^4.18.1"
 	},

src/cli.ts

@@ -6,7 +6,7 @@
 import { getExportEntries } from './utils/parse-package-json/get-export-entries.js';
 import { getAliases } from './utils/parse-package-json/get-aliases.js';
 import { normalizePath } from './utils/normalize-path.js';
-import { getSourcePath } from './utils/get-source-path.js';
+import { getSourcePaths } from './utils/get-source-path.js';
 import { getRollupConfigs } from './utils/get-rollup-configs.js';
 import { getTsconfig } from './utils/get-tsconfig';
 import { log } from './utils/log.js';
@@ -130,7 +130,7 @@
 		const validPath = entry.outputPath.startsWith(distPath);
 
 		if (!validPath) {
 			console.warn(`Ignoring entry outside of ${distPath} directory: package.json#${entry.from}=${stringify(entry.outputPath)}`);
 		}
 
 		return validPath;
@@ -140,10 +140,8 @@
 		throw new Error('No export entries found in package.json');
 	}
 
-	const sourcePaths = await Promise.all(exportEntries.map(async exportEntry => ({
-		...(await getSourcePath(exportEntry, sourcePath, distPath)),
-		exportEntry,
-	})));
+	const sourcePaths = (await Promise.all(exportEntries.map(exportEntry => getSourcePaths(exportEntry, sourcePath, distPath, cwd))));
+	const flatSourcePaths = sourcePaths.flat();
 
 	const rollupConfigs = await getRollupConfigs(
 
@@ -155,7 +153,7 @@
 		 */
 		normalizePath(fs.realpathSync.native(sourcePath), true),
 		distPath,
-		sourcePaths,
+		flatSourcePaths,
 		argv.flags,
 		getAliases(packageJson, cwd),
 		packageJson,
@@ -207,6 +205,6 @@
 		);
 	}
 })().catch((error) => {
 	console.error(error);
 	process.exit(1);
 });

src/local-typescript-loader.ts

@@ -9,5 +9,5 @@
 	}
 };
 
-// eslint-disable-next-line n/global-require, import-x/no-dynamic-require
+// eslint-disable-next-line import-x/no-dynamic-require
 export default require(getLocalTypescriptPath());

src/utils/get-source-path.ts

@@ -1,3 +1,4 @@
+import { globSync } from 'glob';
 import type { ExportEntry } from '../types.js';
 import { fsExists } from './fs-exists.js';
 
@@ -6,10 +7,11 @@
 const tryExtensions = async (
 	pathWithoutExtension: string,
 	extensions: readonly string[],
+	checker: (sourcePath: string)=>Promise<boolean>,
 ) => {
 	for (const extension of extensions) {
 		const pathWithExtension = pathWithoutExtension + extension;
-		if (await fsExists(pathWithExtension)) {
+		if (await checker(pathWithExtension)) {
 			return {
 				extension,
 				path: pathWithExtension,
@@ -33,14 +35,16 @@
 	exportEntry: ExportEntry,
 	source: string,
 	dist: string,
-) => {
+	checker: (sourcePath: string)=>Promise<boolean> = fsExists,
+): Promise<Omit<SourcePath, 'exportEntry'>> => {
 	const sourcePathUnresolved = source + exportEntry.outputPath.slice(dist.length);
 
 	for (const distExtension of distExtensions) {
 		if (exportEntry.outputPath.endsWith(distExtension)) {
 			const sourcePath = await tryExtensions(
 				sourcePathUnresolved.slice(0, -distExtension.length),
 				extensionMap[distExtension],
+				checker,
 			);
 
 			if (sourcePath) {
@@ -55,3 +59,43 @@
 
 	throw new Error(`Could not find matching source file for export path ${stringify(exportEntry.outputPath)}`);
 };
+
+interface SourcePath {
+	exportEntry: ExportEntry;
+	input: string;
+	srcExtension: string;
+	distExtension: string;
+}
+
+export const getSourcePaths = async (
+	exportEntry: ExportEntry,
+	sourcePath: string,
+	distPath: string,
+	cwd: string,
+): Promise<SourcePath[]> => {
+	if (exportEntry.outputPath.includes('*')) {
+		// use glob to resolve matches from the packageJsonRoot directory
+		const matchSet = new Set<string>();
+		const sourceMatch = await getSourcePath(exportEntry, sourcePath, distPath, async (path) => {
+			const matches = globSync(path, { cwd });
+			for (const match of matches) { matchSet.add(match); }
+			return matches.length > 0; // always return false to prevent early exit
+		});
+
+		const matchedPaths = Array.from(matchSet);
+
+		const allMatches = matchedPaths.map(match => ({
+			exportEntry,
+			input: match,
+			srcExtension: sourceMatch.srcExtension,
+			distExtension: sourceMatch.distExtension,
+		}));
+
+		return allMatches;
+	}
+
+	return [{
+		exportEntry,
+		...await getSourcePath(exportEntry, sourcePath, distPath, fsExists),
+	}];
+};