Method resolveModule

src/sys/node/node-resolve-module.ts:10–56

(fromDir: string, moduleId: string, opts?: d.ResolveModuleOptions)

  private resolveModuleCache = new Map<string, string>();

  resolveModule(fromDir: string, moduleId: string, opts?: d.ResolveModuleOptions) {
    const cacheKey = `${fromDir}:${moduleId}`;

    const cachedPath = this.resolveModuleCache.get(cacheKey);
    if (cachedPath) {
      return cachedPath;
    }

    if (opts && opts.manuallyResolve) {
      return this.resolveModuleManually(fromDir, moduleId, cacheKey);
    }

    if (moduleId.startsWith('@types/')) {
      return this.resolveTypesModule(fromDir, moduleId, cacheKey);
    }

    const Module = require('module');

    fromDir = path.resolve(fromDir);
    const fromFile = path.join(fromDir, 'noop.js');

    let dir = normalizePath(
      Module._resolveFilename(moduleId, {
        id: fromFile,
        filename: fromFile,
        paths: Module._nodeModulePaths(fromDir),
      }),
    );

    const root = normalizePath(path.parse(fromDir).root);
    let packageJsonFilePath: string;

    while (dir !== root) {
      dir = normalizePath(path.dirname(dir));
      packageJsonFilePath = path.join(dir, 'package.json');

      if (!fs.existsSync(packageJsonFilePath)) {
        continue;
      }

      this.resolveModuleCache.set(cacheKey, packageJsonFilePath);

      return packageJsonFilePath;
    }

    throw new Error(`error loading "${moduleId}" from "${fromDir}"`);
  }

  resolveTypesModule(fromDir: string, moduleId: string, cacheKey: string) {
    const moduleSplt = moduleId.split('/');