Merge pull request #380 from webpack/issue-355

fix: resolve for exports fields and exports fields

lib/ExtensionAliasPlugin.js

@@ -36,17 +36,40 @@ module.exports = class ExtensionAliasPlugin {
 			.tapAsync("ExtensionAliasPlugin", (request, resolveContext, callback) => {
 				const requestPath = request.request;
 				if (!requestPath || !requestPath.endsWith(extension)) return callback();
-				const resolve = (alias, callback) => {
-					resolver.doResolve(
+				const isAliasString = typeof alias === "string";
+				const resolve = (alias, callback, index) => {
+					const newRequest = `${requestPath.slice(
+						0,
+						-extension.length
+					)}${alias}`;
+
+					return resolver.doResolve(
 						target,
 						{
 							...request,
-							request: `${requestPath.slice(0, -extension.length)}${alias}`,
+							request: newRequest,
 							fullySpecified: true
 						},
 						`aliased from extension alias with mapping '${extension}' to '${alias}'`,
 						resolveContext,
-						callback
+						(err, result) => {
+							// Throw error if we are on the last alias (for multiple aliases) and it failed, always throw if we are not an array or we have only one alias
+							if (!isAliasString && index) {
+								if (index !== this.options.alias.length) {
+									if (resolveContext.log) {
+										resolveContext.log(
+											`Failed to alias from extension alias with mapping '${extension}' to '${alias}' for '${newRequest}': ${err}`
+										);
+									}
+
+									return callback(null, result);
+								}
+
+								return callback(err, result);
+							} else {
+								callback(err, result);
+							}
+						}
 					);
 				};
 
@@ -56,7 +79,7 @@ module.exports = class ExtensionAliasPlugin {
 					// Don't allow other aliasing or raw request
 					return callback(null, null);
 				};
-				if (typeof alias === "string") {
+				if (isAliasString) {
 					resolve(alias, stoppingCallback);
 				} else if (alias.length > 1) {
 					forEachBail(alias, resolve, stoppingCallback);

lib/forEachBail.js

@@ -11,13 +11,17 @@ module.exports = function forEachBail(array, iterator, callback) {
 	let i = 0;
 	const next = () => {
 		let loop = undefined;
-		iterator(array[i++], (err, result) => {
-			if (err || result !== undefined || i >= array.length) {
-				return callback(err, result);
-			}
-			if (loop === false) while (next());
-			loop = true;
-		});
+		iterator(
+			array[i++],
+			(err, result) => {
+				if (err || result !== undefined || i >= array.length) {
+					return callback(err, result);
+				}
+				if (loop === false) while (next());
+				loop = true;
+			},
+			i
+		);
 		if (!loop) loop = false;
 		return loop;
 	};

test/exportsField.js

@@ -2911,4 +2911,125 @@ describe("ExportsFieldPlugin", () => {
 			}
 		);
 	});
+
+	it("should resolve with the `extensionAlias` option", done => {
+		const resolver = ResolverFactory.createResolver({
+			extensions: [".js"],
+			extensionAlias: {
+				".js": [".ts", ".js"]
+			},
+			fileSystem: nodeFileSystem,
+			fullySpecified: true,
+			conditionNames: ["webpack", "default"]
+		});
+		const fixture = path.resolve(
+			__dirname,
+			"./fixtures/exports-field-and-extension-alias/"
+		);
+
+		resolver.resolve({}, fixture, "@org/pkg/string.js", {}, (err, result) => {
+			if (err) return done(err);
+			if (!result) throw new Error("No result");
+			result.should.equal(
+				path.resolve(fixture, "./node_modules/@org/pkg/dist/string.js")
+			);
+			done();
+		});
+	});
+
+	it("should resolve with the `extensionAlias` option #2", done => {
+		const resolver = ResolverFactory.createResolver({
+			extensions: [".js"],
+			extensionAlias: {
+				".js": [".ts", ".js"]
+			},
+			fileSystem: nodeFileSystem,
+			fullySpecified: true,
+			conditionNames: ["webpack", "default"]
+		});
+		const fixture = path.resolve(
+			__dirname,
+			"./fixtures/exports-field-and-extension-alias/"
+		);
+
+		resolver.resolve({}, fixture, "pkg/string.js", {}, (err, result) => {
+			if (err) return done(err);
+			if (!result) throw new Error("No result");
+			result.should.equal(
+				path.resolve(fixture, "./node_modules/pkg/dist/string.js")
+			);
+			done();
+		});
+	});
+
+	it("should resolve with the `extensionAlias` option #3", done => {
+		const resolver = ResolverFactory.createResolver({
+			extensions: [".js"],
+			extensionAlias: {
+				".js": [".foo", ".baz", ".baz", ".ts", ".js"]
+			},
+			fileSystem: nodeFileSystem,
+			fullySpecified: true,
+			conditionNames: ["webpack", "default"]
+		});
+		const fixture = path.resolve(
+			__dirname,
+			"./fixtures/exports-field-and-extension-alias/"
+		);
+
+		resolver.resolve({}, fixture, "pkg/string.js", {}, (err, result) => {
+			if (err) return done(err);
+			if (!result) throw new Error("No result");
+			result.should.equal(
+				path.resolve(fixture, "./node_modules/pkg/dist/string.js")
+			);
+			done();
+		});
+	});
+
+	it("should throw error with the `extensionAlias` option", done => {
+		const resolver = ResolverFactory.createResolver({
+			extensions: [".js"],
+			extensionAlias: {
+				".js": [".ts"]
+			},
+			fileSystem: nodeFileSystem,
+			fullySpecified: true,
+			conditionNames: ["webpack", "default"]
+		});
+		const fixture = path.resolve(
+			__dirname,
+			"./fixtures/exports-field-and-extension-alias/"
+		);
+
+		resolver.resolve({}, fixture, "pkg/string.js", {}, (err, result) => {
+			if (!err) throw new Error(`expect error, got ${result}`);
+			err.should.be.instanceof(Error);
+			err.message.should.match(/Package path \.\/string\.ts is not exported/);
+			done();
+		});
+	});
+
+	it("should throw error with the `extensionAlias` option #2", done => {
+		const resolver = ResolverFactory.createResolver({
+			extensions: [".js"],
+			extensionAlias: {
+				".js": ".ts"
+			},
+			fileSystem: nodeFileSystem,
+			fullySpecified: true,
+			conditionNames: ["webpack", "default"]
+		});
+		const fixture = path.resolve(
+			__dirname,
+			"./fixtures/exports-field-and-extension-alias/"
+		);
+
+		resolver.resolve({}, fixture, "pkg/string.js", {}, (err, result) => {
+			if (!err) throw new Error(`expect error, got ${result}`);
+			err.should.be.instanceof(Error);
+			err.message.should.match(/Package path \.\/string\.ts is not exported/);
+			done();
+		});
+	});
 });