@nestjs/cli/lib/utils/load-builder-config.js

Nest - modern, fast, powerful node.js web framework (@cli)

import { existsSync } from 'fs';
import { createRequire } from 'module';
import { extname, join } from 'path';
import { pathToFileURL } from 'url';
import { resolveModulePath } from './resolve-module-path.js';
const require = createRequire(import.meta.url);
/**
 * Loads a builder (webpack/rspack) configuration file, which may be CommonJS,
 * native ESM, or JSON. When `configPath` is the builder's default filename and
 * no such file exists, the project simply has no overrides, so an identity
 * factory is returned; an explicitly configured path that cannot be found is
 * an error.
 */
export async function loadBuilderConfig(configPath, defaultPath, cwd = process.cwd()) {
    const pathToConfigFile = join(cwd, configPath);
    // `require.resolve` handles extensionless and directory-index paths, but
    // does not know about ESM-only extensions, hence the `existsSync` fallback.
    const resolvedPath = resolveModulePath(pathToConfigFile) ??
        (existsSync(pathToConfigFile) ? pathToConfigFile : undefined);
    if (!resolvedPath) {
        if (configPath === defaultPath) {
            return ((_config) => ({}));
        }
        throw new Error(`Could not find the builder configuration file "${configPath}".`);
    }
    if (extname(resolvedPath) === '.json') {
        return require(resolvedPath);
    }
    const imported = await import(pathToFileURL(resolvedPath).href);
    const result = imported.default ?? imported;
    // A CommonJS file compiled from TypeScript exposes its real export under a
    // second `default`, behind the `__esModule` marker Node preserves as-is.
    return (isTranspiledEsModule(result) ? result.default : result);
}
function isTranspiledEsModule(value) {
    return (!!value &&
        typeof value === 'object' &&
        value.__esModule === true &&
        'default' in value);
}