improve resolving of build dependencies when `exports` field is used

lib/FileSystemInfo.js

@@ -27,11 +27,12 @@ const RBDT_RESOLVE_CJS = 0;
 const RBDT_RESOLVE_ESM = 1;
 const RBDT_RESOLVE_DIRECTORY = 2;
 const RBDT_RESOLVE_CJS_FILE = 3;
-const RBDT_RESOLVE_ESM_FILE = 4;
-const RBDT_DIRECTORY = 5;
-const RBDT_FILE = 6;
-const RBDT_DIRECTORY_DEPENDENCIES = 7;
-const RBDT_FILE_DEPENDENCIES = 8;
+const RBDT_RESOLVE_CJS_FILE_AS_CHILD = 4;
+const RBDT_RESOLVE_ESM_FILE = 5;
+const RBDT_DIRECTORY = 6;
+const RBDT_FILE = 7;
+const RBDT_DIRECTORY_DEPENDENCIES = 8;
+const RBDT_FILE_DEPENDENCIES = 9;
 
 const INVALID = Symbol("invalid");
 
@@ -1103,15 +1104,23 @@ class FileSystemInfo {
 		const resolveCjs = createResolver({
 			extensions: [".js", ".json", ".node"],
 			conditionNames: ["require", "node"],
+			exportsFields: ["exports"],
+			fileSystem: this.fs
+		});
+		const resolveCjsAsChild = createResolver({
+			extensions: [".js", ".json", ".node"],
+			conditionNames: ["require", "node"],
+			exportsFields: [],
 			fileSystem: this.fs
 		});
 		const resolveEsm = createResolver({
 			extensions: [".js", ".json", ".node"],
 			fullySpecified: true,
 			conditionNames: ["import", "node"],
+			exportsFields: ["exports"],
 			fileSystem: this.fs
 		});
-		return { resolveContext, resolveEsm, resolveCjs };
+		return { resolveContext, resolveEsm, resolveCjs, resolveCjsAsChild };
 	}
 
 	/**
@@ -1124,7 +1133,8 @@ class FileSystemInfo {
 		const {
 			resolveContext,
 			resolveEsm,
-			resolveCjs
+			resolveCjs,
+			resolveCjsAsChild
 		} = this._createBuildDependenciesResolvers();
 
 		/** @type {Set<string>} */
@@ -1242,7 +1252,7 @@ class FileSystemInfo {
 								resolveResults.set(key, result);
 							} else {
 								invalidResolveResults.add(key);
-								this.logger.debug(
+								this.logger.warn(
 									`Resolving '${path}' in ${context} for build dependencies doesn't lead to expected result '${expected}', but to '${result}' instead. Resolving dependencies are ignored for this path.\n${pathToString(
 										job
 									)}`
@@ -1299,6 +1309,10 @@ class FileSystemInfo {
 						resolveFile(path, "f", resolveCjs);
 						break;
 					}
+					case RBDT_RESOLVE_CJS_FILE_AS_CHILD: {
+						resolveFile(path, "c", resolveCjsAsChild);
+						break;
+					}
 					case RBDT_RESOLVE_ESM_FILE: {
 						resolveFile(path, "e", resolveEsm);
 						break;
@@ -1378,11 +1392,29 @@ class FileSystemInfo {
 									const context = dirname(this.fs, path);
 									for (const modulePath of module.paths) {
 										if (childPath.startsWith(modulePath)) {
-											let request = childPath.slice(modulePath.length + 1);
+											let subPath = childPath.slice(modulePath.length + 1);
+											const packageMatch = /^(@[^\\/]+[\\/])[^\\/]+/.exec(
+												subPath
+											);
+											if (packageMatch) {
+												push({
+													type: RBDT_FILE,
+													context: undefined,
+													path:
+														modulePath +
+														childPath[modulePath.length] +
+														packageMatch[0] +
+														childPath[modulePath.length] +
+														"package.json",
+													expected: false,
+													issuer: job
+												});
+											}
+											let request = subPath.replace(/\\/g, "/");
 											if (request.endsWith(".js"))
 												request = request.slice(0, -3);
 											push({
-												type: RBDT_RESOLVE_CJS_FILE,
+												type: RBDT_RESOLVE_CJS_FILE_AS_CHILD,
 												context,
 												path: request,
 												expected: child.filename,
@@ -1573,6 +1605,7 @@ class FileSystemInfo {
 	checkResolveResultsValid(resolveResults, callback) {
 		const {
 			resolveCjs,
+			resolveCjsAsChild,
 			resolveEsm,
 			resolveContext
 		} = this._createBuildDependenciesResolvers();
@@ -1600,6 +1633,15 @@ class FileSystemInfo {
 							callback();
 						});
 						break;
+					case "c":
+						resolveCjsAsChild(context, path, {}, (err, result) => {
+							if (expectedResult === false)
+								return callback(err ? undefined : INVALID);
+							if (err) return callback(err);
+							if (result !== expectedResult) return callback(INVALID);
+							callback();
+						});
+						break;
 					case "e":
 						resolveEsm(context, path, {}, (err, result) => {
 							if (expectedResult === false)

test/BuildDependencies.test.js

@@ -99,10 +99,14 @@ describe("BuildDependencies", () => {
 		const output2 = await exec("2");
 		expect(output2).toMatch(/but build dependencies have changed/);
 		expect(output2).toMatch(/Captured build dependencies/);
+		expect(output2).not.toMatch(/Assuming/);
+		expect(output2).not.toMatch(/<w>/);
 		const output3 = await exec("3");
 		expect(output3).not.toMatch(/resolving of build dependencies is invalid/);
 		expect(output3).not.toMatch(/but build dependencies have changed/);
 		expect(output3).not.toMatch(/Captured build dependencies/);
+		expect(output3).not.toMatch(/Assuming/);
+		expect(output3).not.toMatch(/<w>/);
 		fs.writeFileSync(
 			path.resolve(inputDirectory, "package.json"),
 			JSON.stringify({

test/fixtures/buildDependencies/node_modules/dep-with-exports/package.json

@@ -0,0 +1,8 @@
+{
+  "exports": {
+    ".": "./main-entry.js",
+    "./sub": {
+      "require": "./sub-entry.js"
+    }
+  }
+}

test/fixtures/buildDependencies/node_modules/dependency-with-exports/main.js

@@ -0,0 +1,4 @@
+require("dep-with-exports");
+require("dep-with-exports/sub");
+require("dep-without-package.json/main-entry");
+require("dep-without-package.json/sub-entry");

test/fixtures/buildDependencies/node_modules/dependency-with-exports/package.json

@@ -0,0 +1,3 @@
+{
+  "exports": "./main.js"
+}

test/fixtures/buildDependencies/node_modules/require-dependency-with-exports/index.js

@@ -0,0 +1 @@
+require("dependency-with-exports");

test/fixtures/buildDependencies/run.js

@@ -10,6 +10,7 @@ const options = JSON.parse(process.argv[3]);
 const esm = +process.versions.modules >= 83;
 
 if (esm) {
+	require("require-dependency-with-exports");
 	import("./esm.mjs").then(module => {
 		run(module);
 	});
@@ -56,6 +57,7 @@ function run({ default: value2, asyncDep: value3 }) {
 				type: "filesystem",
 				cacheDirectory: path.resolve(__dirname, "../../js/buildDepsCache"),
 				buildDependencies: {
+					defaultWebpack: [],
 					config: [
 						__filename,
 						path.resolve(__dirname, "../../../node_modules/.yarn-integrity")