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privatenumberprivatenumber
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refactor: cjs loader (#2)
1 parent f38db84 commit b63019c

15 files changed

+322
-263
lines changed

‎src/cjs/api/global-require-patch.ts

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import Module from 'module';
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import { extensions } from './module-extensions.js';
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import { resolveFilename } from './module-resolve-filename.js';
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export const register = () => {
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const { sourceMapsEnabled } = process;
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const { _extensions, _resolveFilename } = Module;
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// register
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process.setSourceMapsEnabled(true);
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// @ts-expect-error overwriting read-only property
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Module._extensions = extensions;
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Module._resolveFilename = resolveFilename;
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// unregister
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return () => {
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if (sourceMapsEnabled === false) {
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process.setSourceMapsEnabled(false);
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}
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// @ts-expect-error overwriting read-only property
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Module._extensions = _extensions;
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Module._resolveFilename = _resolveFilename;
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};
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};

‎src/cjs/api/index.ts

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export { register } from './global-require-patch.js';

‎src/cjs/api/module-extensions.ts

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import fs from 'fs';
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import Module from 'module';
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import { createFilesMatcher } from 'get-tsconfig';
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import type { TransformOptions } from 'esbuild';
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import { transformSync } from '../../utils/transform/index.js';
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import { transformDynamicImport } from '../../utils/transform/transform-dynamic-import.js';
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import { isESM } from '../../utils/esm-pattern.js';
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import { shouldApplySourceMap, inlineSourceMap } from '../../source-map.js';
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import { parent } from '../../utils/ipc/client.js';
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import { tsconfig } from './utils.js';
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const typescriptExtensions = [
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'.cts',
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'.mts',
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'.ts',
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'.tsx',
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'.jsx',
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];
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const transformExtensions = [
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'.js',
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'.cjs',
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'.mjs',
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];
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const fileMatcher = tsconfig && createFilesMatcher(tsconfig);
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// Clone Module._extensions with null prototype
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export const extensions = Object.assign(Object.create(null), Module._extensions);
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const defaultLoader = extensions['.js'];
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const transformer = (
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module: Module,
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filePath: string,
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) => {
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// For tracking dependencies in watch mode
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if (parent?.send) {
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parent.send({
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type: 'dependency',
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path: filePath,
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});
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}
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const transformTs = typescriptExtensions.some(extension => filePath.endsWith(extension));
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const transformJs = transformExtensions.some(extension => filePath.endsWith(extension));
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if (!transformTs && !transformJs) {
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return defaultLoader(module, filePath);
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}
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let code = fs.readFileSync(filePath, 'utf8');
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if (filePath.endsWith('.cjs')) {
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// Contains native ESM check
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const transformed = transformDynamicImport(filePath, code);
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if (transformed) {
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code = (
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shouldApplySourceMap()
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? inlineSourceMap(transformed)
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: transformed.code
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);
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}
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} else if (
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transformTs
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// CommonJS file but uses ESM import/export
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|| isESM(code)
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) {
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const transformed = transformSync(
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code,
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filePath,
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{
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tsconfigRaw: fileMatcher?.(filePath) as TransformOptions['tsconfigRaw'],
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},
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);
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code = (
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shouldApplySourceMap()
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? inlineSourceMap(transformed)
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: transformed.code
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);
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}
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module._compile(code, filePath);
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};
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[
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/**
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* Handles .cjs, .cts, .mts & any explicitly specified extension that doesn't match any loaders
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*
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* Any file requested with an explicit extension will be loaded using the .js loader:
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* https://github.com/nodejs/node/blob/e339e9c5d71b72fd09e6abd38b10678e0c592ae7/lib/internal/modules/cjs/loader.js#L430
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*/
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'.js',
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/**
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* Loaders for implicitly resolvable extensions
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* https://github.com/nodejs/node/blob/v12.16.0/lib/internal/modules/cjs/loader.js#L1166
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*/
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'.ts',
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'.tsx',
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'.jsx',
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].forEach((extension) => {
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extensions[extension] = transformer;
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});
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/**
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* Loaders for explicitly resolvable extensions
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* (basically just .mjs because CJS loader has a special handler for it)
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*
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* Loaders for extensions .cjs, .cts, & .mts don't need to be
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* registered because they're explicitly specified and unknown
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* extensions (incl .cjs) fallsback to using the '.js' loader:
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* https://github.com/nodejs/node/blob/v18.4.0/lib/internal/modules/cjs/loader.js#L430
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*
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* That said, it's actually ".js" and ".mjs" that get special treatment
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* rather than ".cjs" (it might as well be ".random-ext")
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*/
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Object.defineProperty(extensions, '.mjs', {
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value: transformer,
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// Prevent Object.keys from detecting these extensions
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// when CJS loader iterates over the possible extensions
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enumerable: false,
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});

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

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import path from 'path';
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import Module from 'module';
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import { createPathsMatcher } from 'get-tsconfig';
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import { resolveTsPath } from '../../utils/resolve-ts-path.js';
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import type { NodeError } from '../../types.js';
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import { isRelativePathPattern } from '../../utils/is-relative-path-pattern.js';
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import {
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isTsFilePatten,
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tsconfig,
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} from './utils.js';
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const nodeModulesPath = `${path.sep}node_modules${path.sep}`;
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const tsconfigPathsMatcher = tsconfig && createPathsMatcher(tsconfig);
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type ResolveFilename = typeof Module._resolveFilename;
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const defaultResolver = Module._resolveFilename.bind(Module);
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/**
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* Typescript gives .ts, .cts, or .mts priority over actual .js, .cjs, or .mjs extensions
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*/
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const resolveTsFilename = (
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request: string,
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parent: Module.Parent,
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isMain: boolean,
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options?: Record<PropertyKey, unknown>,
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) => {
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const tsPath = resolveTsPath(request);
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if (
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parent?.filename
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&& (
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isTsFilePatten.test(parent.filename)
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|| tsconfig?.config.compilerOptions?.allowJs
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)
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&& tsPath
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) {
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for (const tryTsPath of tsPath) {
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try {
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return defaultResolver(
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tryTsPath,
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parent,
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isMain,
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options,
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);
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} catch (error) {
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const { code } = error as NodeError;
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if (
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code !== 'MODULE_NOT_FOUND'
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&& code !== 'ERR_PACKAGE_PATH_NOT_EXPORTED'
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) {
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throw error;
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}
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}
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}
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}
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};
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export const resolveFilename: ResolveFilename = (
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request,
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parent,
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isMain,
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options,
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) => {
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// Strip query string
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const queryIndex = request.indexOf('?');
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if (queryIndex !== -1) {
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request = request.slice(0, queryIndex);
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}
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if (
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tsconfigPathsMatcher
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// bare specifier
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&& !isRelativePathPattern.test(request)
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// Dependency paths should not be resolved using tsconfig.json
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&& !parent?.filename?.includes(nodeModulesPath)
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) {
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const possiblePaths = tsconfigPathsMatcher(request);
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for (const possiblePath of possiblePaths) {
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const tsFilename = resolveTsFilename(possiblePath, parent, isMain, options);
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if (tsFilename) {
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return tsFilename;
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}
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try {
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return defaultResolver(
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possiblePath,
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parent,
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isMain,
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options,
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);
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} catch {}
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}
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}
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const tsFilename = resolveTsFilename(request, parent, isMain, options);
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if (tsFilename) {
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return tsFilename;
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}
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return defaultResolver(request, parent, isMain, options);
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};

‎src/cjs/api/utils.ts

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import path from 'path';
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import {
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getTsconfig,
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parseTsconfig,
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} from 'get-tsconfig';
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export const isTsFilePatten = /\.[cm]?tsx?$/;
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export const tsconfig = (
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process.env.TSX_TSCONFIG_PATH
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? {
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path: path.resolve(process.env.TSX_TSCONFIG_PATH),
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config: parseTsconfig(process.env.TSX_TSCONFIG_PATH),
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}
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: getTsconfig()
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);

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