refactor(cjs): resolver organized in multiple files

src/cjs/api/module-resolve-filename/index.ts

@@ -0,0 +1,92 @@
+import Module from 'node:module';
+import { fileURLToPath } from 'node:url';
+import {
+	isFilePath,
+	fileUrlPrefix,
+	tsExtensionsPattern,
+	nodeModulesPath,
+} from '../../../utils/path-utils.js';
+import { tsconfigPathsMatcher } from '../../../utils/tsconfig.js';
+import type { ResolveFilename, SimpleResolve, LoaderState } from '../types.js';
+import { createImplicitResolver } from './resolve-implicit-extensions.js';
+import { interopCjsExports } from './interop-cjs-exports.js';
+import { createTsExtensionResolver } from './resolve-ts-extensions.js';
+import { preserveQuery } from './preserve-query.js';
+
+const resolveTsPaths = (
+	request: string,
+	parent: Module.Parent | undefined,
+	nextResolve: SimpleResolve,
+) => {
+	// Support file protocol
+	if (request.startsWith(fileUrlPrefix)) {
+		request = fileURLToPath(request);
+	}
+
+	// Resolve TS path alias
+	if (
+		tsconfigPathsMatcher
+
+		// bare specifier
+		&& !isFilePath(request)
+
+		// Dependency paths should not be resolved using tsconfig.json
+		&& !parent?.filename?.includes(nodeModulesPath)
+	) {
+		const possiblePaths = tsconfigPathsMatcher(request);
+		for (const possiblePath of possiblePaths) {
+			try {
+				return nextResolve(possiblePath);
+			} catch {}
+		}
+	}
+
+	return nextResolve(request);
+};
+
+export const createResolveFilename = (
+	state: LoaderState,
+	nextResolve: ResolveFilename,
+	namespace?: string,
+): ResolveFilename => (
+	request,
+	parent,
+	...restOfArgs
+) => {
+	if (state.enabled === false) {
+		return nextResolve(request, parent, ...restOfArgs);
+	}
+
+	request = interopCjsExports(request);
+
+	const [
+		cleanRequest,
+		searchParams,
+		appendQuery,
+	] = preserveQuery(request, parent);
+
+	// If request namespace doesnt match the namespace, ignore
+	if ((searchParams.get('namespace') ?? undefined) !== namespace) {
+		return nextResolve(request, parent, ...restOfArgs);
+	}
+
+	let nextResolveSimple: SimpleResolve = request_ => nextResolve(
+		request_,
+		parent,
+		...restOfArgs,
+	);
+
+	nextResolveSimple = createTsExtensionResolver(
+		nextResolveSimple,
+		Boolean(parent?.filename && tsExtensionsPattern.test(parent.filename)),
+	);
+
+	nextResolveSimple = createImplicitResolver(nextResolveSimple);
+
+	const resolved = resolveTsPaths(cleanRequest, parent, nextResolveSimple);
+
+	return appendQuery(
+		resolved,
+		restOfArgs.length,
+	);
+};