handle exports field when using PnP

fixes #270

Author: sokra

lib/PnpPlugin.js

@@ -39,10 +39,16 @@ module.exports = class PnpPlugin {
 				// The trailing slash indicates to PnP that this value is a folder rather than a file
 				const issuer = `${request.path}/`;
 
+				const packageMatch = /^(@[^/]+\/)?[^/]+/.exec(req);
+				if (!packageMatch) return callback();
+
+				const packageName = packageMatch[0];
+				const innerRequest = `.${req.slice(packageName.length)}`;
+
 				let resolution;
 				let apiResolution;
 				try {
-					resolution = this.pnpApi.resolveToUnqualified(req, issuer, {
+					resolution = this.pnpApi.resolveToUnqualified(packageName, issuer, {
 						considerBuiltins: false
 					});
 					if (resolveContext.fileDependencies) {
@@ -67,7 +73,7 @@ module.exports = class PnpPlugin {
 					return callback(error);
 				}
 
-				if (resolution === req) return callback();
+				if (resolution === packageName) return callback();
 
 				if (apiResolution && resolveContext.fileDependencies) {
 					resolveContext.fileDependencies.add(apiResolution);
@@ -76,10 +82,9 @@ module.exports = class PnpPlugin {
 				const obj = {
 					...request,
 					path: resolution,
-					request: undefined,
+					request: innerRequest,
 					ignoreSymlinks: true,
-					fullySpecified:
-						request.fullySpecified && !/^(@[^/]+\/)?[^/]+$/.test(req)
+					fullySpecified: request.fullySpecified && innerRequest !== "."
 				};
 				resolver.doResolve(
 					target,

lib/ResolverFactory.js

@@ -395,7 +395,9 @@ exports.createResolver = function (options) {
 				new ModulesInHierachicDirectoriesPlugin("raw-module", item, "module")
 			);
 			if (item.includes("node_modules") && pnpApi) {
-				plugins.push(new PnpPlugin("raw-module", pnpApi, "relative"));
+				plugins.push(
+					new PnpPlugin("raw-module", pnpApi, "undescribed-resolve-in-package")
+				);
 			}
 		} else {
 			plugins.push(new ModulesInRootPlugin("raw-module", item, "module"));

test/fixtures/pnp/pkg3/a.js

@@ -0,0 +1 @@
+module.exports = 1;

test/fixtures/pnp/pkg3/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@exports-field/core",
+  "version": "1.0.0",
+  "exports": {
+    ".": "./a.js",
+    "./x": "./a.js"
+  }
+}

test/pnp.js

@@ -72,28 +72,22 @@ describe("pnp", () => {
 		});
 	});
 	it("should resolve by going through the pnp api", done => {
-		pnpApi.mocks.set(
-			"pkg/dir/index.js",
-			path.resolve(fixture, "pkg/dir/index.js")
-		);
+		pnpApi.mocks.set("pkg", path.resolve(fixture, "pkg"));
 		resolver.resolve({}, __dirname, "pkg/dir/index.js", {}, (err, result) => {
 			if (err) return done(err);
 			result.should.equal(path.resolve(fixture, "pkg/dir/index.js"));
 			done();
 		});
 	});
 	it("should not resolve a not fully specified request when fullySpecified is set", done => {
-		pnpApi.mocks.set("pkg/dir/index", path.resolve(fixture, "pkg/dir/index"));
+		pnpApi.mocks.set("pkg", path.resolve(fixture, "pkg"));
 		resolver.resolve({}, __dirname, "pkg/dir/index", {}, (err, result) => {
 			err.should.be.instanceof(Error);
 			done();
 		});
 	});
 	it("should track dependency to the pnp api", done => {
-		pnpApi.mocks.set(
-			"pkg/dir/index.js",
-			path.resolve(fixture, "pkg/dir/index.js")
-		);
+		pnpApi.mocks.set("pkg", path.resolve(fixture, "pkg"));
 		pnpApi.mocks.set("pnpapi", path.resolve(fixture, ".pnp.js"));
 		const fileDependencies = new Set();
 		resolver.resolve(
@@ -131,7 +125,7 @@ describe("pnp", () => {
 		"should not resolve symlinks",
 		isAdmin
 			? done => {
-					pnpApi.mocks.set("pkg/symlink", path.resolve(fixture, "pkg/symlink"));
+					pnpApi.mocks.set("pkg", path.resolve(fixture, "pkg"));
 					resolverFuzzy.resolve(
 						{},
 						__dirname,
@@ -149,10 +143,7 @@ describe("pnp", () => {
 			: undefined
 	);
 	it("should properly deal with other extensions", done => {
-		pnpApi.mocks.set(
-			"@user/pkg/typescript",
-			path.resolve(fixture, "pkg/typescript")
-		);
+		pnpApi.mocks.set("@user/pkg", path.resolve(fixture, "pkg"));
 		resolverFuzzy.resolve(
 			{},
 			__dirname,
@@ -166,10 +157,7 @@ describe("pnp", () => {
 		);
 	});
 	it("should properly deal package.json alias", done => {
-		pnpApi.mocks.set(
-			"pkg/package-alias",
-			path.resolve(fixture, "pkg/package-alias")
-		);
+		pnpApi.mocks.set("pkg", path.resolve(fixture, "pkg"));
 		resolverFuzzy.resolve(
 			{},
 			__dirname,
@@ -185,7 +173,7 @@ describe("pnp", () => {
 		);
 	});
 	it("should prefer normal modules over pnp resolves", done => {
-		pnpApi.mocks.set("m1/a.js", path.resolve(fixture, "pkg/a.js"));
+		pnpApi.mocks.set("m1", path.resolve(fixture, "pkg"));
 		resolver.resolve(
 			{},
 			path.resolve(__dirname, "fixtures"),
@@ -199,10 +187,7 @@ describe("pnp", () => {
 		);
 	});
 	it("should prefer alias over pnp resolves", done => {
-		pnpApi.mocks.set(
-			"alias/index.js",
-			path.resolve(fixture, "pkg/dir/index.js")
-		);
+		pnpApi.mocks.set("alias", path.resolve(fixture, "pkg/dir"));
 		resolver.resolve(
 			{},
 			path.resolve(__dirname, "fixtures"),
@@ -216,11 +201,11 @@ describe("pnp", () => {
 		);
 	});
 	it("should prefer pnp over modules after node_modules", done => {
-		pnpApi.mocks.set("m2/a.js", path.resolve(fixture, "pkg/index.js"));
+		pnpApi.mocks.set("m2", path.resolve(fixture, "pkg"));
 		resolver.resolve(
 			{},
 			path.resolve(__dirname, "fixtures"),
-			"m2/a.js",
+			"m2/index.js",
 			{},
 			(err, result) => {
 				if (err) return done(err);
@@ -242,4 +227,32 @@ describe("pnp", () => {
 			}
 		);
 	});
+	it("should handle the exports field when using PnP", done => {
+		pnpApi.mocks.set("m1", path.resolve(fixture, "pkg3"));
+		resolver.resolve(
+			{},
+			path.resolve(__dirname, "fixtures"),
+			"m1",
+			{},
+			(err, result) => {
+				if (err) return done(err);
+				result.should.equal(path.resolve(fixture, "pkg3/a.js"));
+				done();
+			}
+		);
+	});
+	it("should handle the exports field when using PnP (with sub path)", done => {
+		pnpApi.mocks.set("@user/m1", path.resolve(fixture, "pkg3"));
+		resolver.resolve(
+			{},
+			path.resolve(__dirname, "fixtures"),
+			"@user/m1/x",
+			{},
+			(err, result) => {
+				if (err) return done(err);
+				result.should.equal(path.resolve(fixture, "pkg3/a.js"));
+				done();
+			}
+		);
+	});
 });