fix: improve error messages when files are missing or mismatched

Author: comp615

src/utils/get-source-path.ts

@@ -9,6 +9,7 @@ const tryExtensions = async (
 ) => {
 	for (const extension of extensions) {
 		const pathWithExtension = pathWithoutExtension + extension;
+		console.log("checking for path", pathWithExtension);
 		if (await fsExists(pathWithExtension)) {
 			return {
 				extension,
@@ -36,22 +37,23 @@ export const getSourcePath = async (
 ) => {
 	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],
-			);
-
-			if (sourcePath) {
-				return {
-					input: sourcePath.path,
-					srcExtension: sourcePath.extension,
-					distExtension,
-				};
-			}
+	const distExtension = distExtensions.find((distExtension) => exportEntry.outputPath.endsWith(distExtension));
+	if (distExtension) {
+		const sourcePathWithoutExtension = sourcePathUnresolved.slice(0, -distExtension.length);
+		const sourcePath = await tryExtensions(
+			sourcePathWithoutExtension,
+			extensionMap[distExtension],
+		);
+
+		if (sourcePath) {
+			return {
+				input: sourcePath.path,
+				srcExtension: sourcePath.extension,
+				distExtension,
+			};
 		}
+		throw new Error(`Could not find matching source file for export path: ${stringify(exportEntry.outputPath)}; Expected: ${sourcePathWithoutExtension}[${extensionMap[distExtension].join('|')}]`);
 	}
 
-	throw new Error(`Could not find matching source file for export path ${stringify(exportEntry.outputPath)}`);
+	throw new Error(`Package.json output path contains invalid extension: ${stringify(exportEntry.outputPath)}; Expected: ${distExtensions.join(', ')}`);
 };

tests/specs/error-cases.ts

@@ -106,5 +106,50 @@ export default testSuite(({ describe }, nodePath: string) => {
 			expect(pkgrollProcess.stderr).toMatch('Ignoring entry outside of ./dist/ directory: package.json#main="/dist/main.js"');
 			expect(pkgrollProcess.stderr).toMatch('No export entries found in package.json');
 		});
+
+		test('cannot find matching source file', async () => {
+			await using fixture = await createFixture({
+				...packageFixture(),
+				'package.json': createPackageJson({
+					name: 'pkg',
+					main: 'dist/missing.js',
+					module: 'dist/missing.mjs',
+				}),
+			});
+
+			const pkgrollProcess = await pkgroll(
+				[],
+				{
+					cwd: fixture.path,
+					nodePath,
+					reject: false,
+				},
+			);
+			expect(pkgrollProcess.exitCode).toBe(1);
+			expect(pkgrollProcess.stderr).toMatch('Could not find matching source file for export path');
+			expect(pkgrollProcess.stderr).toMatch('Expected: ./src/missing[.js|.ts|.tsx|.mts|.cts]');
+		});
+
+		test('unexpected extension', async () => {
+			await using fixture = await createFixture({
+				...packageFixture(),
+				'package.json': createPackageJson({
+					name: 'pkg',
+					main: 'dist/index.foo',
+				}),
+			});
+
+			const pkgrollProcess = await pkgroll(
+				[],
+				{
+					cwd: fixture.path,
+					nodePath,
+					reject: false,
+				},
+			);
+			expect(pkgrollProcess.exitCode).toBe(1);
+			expect(pkgrollProcess.stderr).toMatch('Error: Package.json output path contains invalid extension');
+			expect(pkgrollProcess.stderr).toMatch('Expected: .d.ts, .d.mts, .d.cts, .js, .mjs, .cjs');
+		});
 	});
 });