Function readFile

packages/node/src/build.ts:238–301

(fsPath)

      },
      ignore: config.excludeFiles,
      async readFile(fsPath) {
        const relPath = relative(baseDir, fsPath);

        // If this file has already been read then return from the cache
        const cached = sourceCache.get(relPath);
        if (typeof cached !== 'undefined') return cached;

        try {
          let entry: File | undefined;
          let source: string | Buffer = readFileSync(fsPath);

          const { mode } = lstatSync(fsPath);
          if (isSymbolicLink(mode)) {
            entry = new FileFsRef({ fsPath, mode });
          }

          if (isEdgeFunction && basename(fsPath) === 'package.json') {
            // For Edge Functions, patch "main" field to prefer "browser" or "module"
            const pkgJson = JSON.parse(source.toString());
            for (const prop of ['browser', 'module']) {
              const val = pkgJson[prop];
              if (typeof val === 'string') {
                debug(`Using "${prop}" field in ${fsPath}`);
                pkgJson.main = val;

                // Create the `entry` with the original so that the output is unmodified
                if (!entry) {
                  entry = new FileBlob({ data: source, mode });
                }

                // Return the modified `package.json` to nft
                source = JSON.stringify(pkgJson);
                break;
              }
            }
          }

          if (
            (fsPath.endsWith('.ts') && !fsPath.endsWith('.d.ts')) ||
            fsPath.endsWith('.tsx') ||
            fsPath.endsWith('.mts') ||
            fsPath.endsWith('.cts')
          ) {
            source = compileTypeScript(fsPath, source.toString());
          }

          if (!entry) {
            entry = new FileBlob({ data: source, mode });
          }
          fsCache.set(relPath, entry);
          sourceCache.set(relPath, source);
          return source;
        } catch (error: unknown) {
          if (
            isErrnoException(error) &&
            (error.code === 'ENOENT' || error.code === 'EISDIR')
          ) {
            // `null` represents a not found