private _buildTransformResult()

in packages/jest-transform/src/ScriptTransformer.ts [359:452]
69 lines of code
19 McCabe index (conditional complexity)

  private _buildTransformResult(
    filename: string,
    cacheFilePath: string,
    content: string,
    transformer: Transformer | undefined,
    shouldCallTransform: boolean,
    options: ReducedTransformOptions,
    processed: TransformedSource | null,
    sourceMapPath: string | null,
  ): TransformResult {
    let transformed: TransformedSource = {
      code: content,
      map: null,
    };

    if (transformer && shouldCallTransform) {
      if (typeof processed === 'string') {
        transformed.code = processed;
      } else if (processed != null && typeof processed.code === 'string') {
        transformed = processed;
      } else {
        throw new Error(makeInvalidReturnValueError());
      }
    }

    if (!transformed.map) {
      try {
        //Could be a potential freeze here.
        //See: https://github.com/facebook/jest/pull/5177#discussion_r158883570
        const inlineSourceMap = sourcemapFromSource(transformed.code);
        if (inlineSourceMap) {
          transformed.map = inlineSourceMap.toObject();
        }
      } catch {
        const transformPath = this._getTransformPath(filename);
        invariant(transformPath);
        console.warn(makeInvalidSourceMapWarning(filename, transformPath));
      }
    }

    // That means that the transform has a custom instrumentation
    // logic and will handle it based on `config.collectCoverage` option
    const transformWillInstrument =
      shouldCallTransform && transformer && transformer.canInstrument;

    // Apply instrumentation to the code if necessary, keeping the instrumented code and new map
    let map = transformed.map;
    let code;
    if (!transformWillInstrument && options.instrument) {
      /**
       * We can map the original source code to the instrumented code ONLY if
       * - the process of transforming the code produced a source map e.g. ts-jest
       * - we did not transform the source code
       *
       * Otherwise we cannot make any statements about how the instrumented code corresponds to the original code,
       * and we should NOT emit any source maps
       *
       */
      const shouldEmitSourceMaps =
        (transformer != null && map != null) || transformer == null;

      const instrumented = this._instrumentFile(
        filename,
        transformed,
        shouldEmitSourceMaps,
        options,
      );

      code =
        typeof instrumented === 'string' ? instrumented : instrumented.code;
      map = typeof instrumented === 'string' ? null : instrumented.map;
    } else {
      code = transformed.code;
    }

    if (map) {
      const sourceMapContent =
        typeof map === 'string' ? map : JSON.stringify(map);

      invariant(sourceMapPath, 'We should always have default sourceMapPath');

      writeCacheFile(sourceMapPath, sourceMapContent);
    } else {
      sourceMapPath = null;
    }

    writeCodeCacheFile(cacheFilePath, code);

    return {
      code,
      originalCode: content,
      sourceMapPath,
    };
  }