private async _getCoverageResult()

in packages/jest-reporters/src/CoverageReporter.ts [422:504]
66 lines of code
8 McCabe index (conditional complexity)

  private async _getCoverageResult(): Promise<{
    map: istanbulCoverage.CoverageMap;
    reportContext: istanbulReport.Context;
  }> {
    if (this._globalConfig.coverageProvider === 'v8') {
      const mergedCoverages = mergeProcessCovs(
        this._v8CoverageResults.map(cov => ({result: cov.map(r => r.result)})),
      );

      const fileTransforms = new Map<string, RuntimeTransformResult>();

      this._v8CoverageResults.forEach(res =>
        res.forEach(r => {
          if (r.codeTransformResult && !fileTransforms.has(r.result.url)) {
            fileTransforms.set(r.result.url, r.codeTransformResult);
          }
        }),
      );

      const transformedCoverage = await Promise.all(
        mergedCoverages.result.map(async res => {
          const fileTransform = fileTransforms.get(res.url);

          let sourcemapContent: FixedRawSourceMap | undefined = undefined;

          if (
            fileTransform?.sourceMapPath &&
            fs.existsSync(fileTransform.sourceMapPath)
          ) {
            sourcemapContent = JSON.parse(
              fs.readFileSync(fileTransform.sourceMapPath, 'utf8'),
            );
          }

          const converter = v8toIstanbul(
            res.url,
            fileTransform?.wrapperLength ?? 0,
            fileTransform && sourcemapContent
              ? {
                  originalSource: fileTransform.originalCode,
                  source: fileTransform.code,
                  sourceMap: {
                    sourcemap: {file: res.url, ...sourcemapContent},
                  },
                }
              : {source: fs.readFileSync(res.url, 'utf8')},
          );

          await converter.load();

          converter.applyCoverage(res.functions);

          const istanbulData = converter.toIstanbul();

          converter.destroy();

          return istanbulData;
        }),
      );

      const map = istanbulCoverage.createCoverageMap({});

      transformedCoverage.forEach(res => map.merge(res));

      const reportContext = istanbulReport.createContext({
        coverageMap: map,
        dir: this._globalConfig.coverageDirectory,
        watermarks: getWatermarks(this._globalConfig),
      });

      return {map, reportContext};
    }

    const map = await this._sourceMapStore.transformCoverage(this._coverageMap);
    const reportContext = istanbulReport.createContext({
      coverageMap: map,
      dir: this._globalConfig.coverageDirectory,
      sourceFinder: this._sourceMapStore.sourceFinder,
      watermarks: getWatermarks(this._globalConfig),
    });

    return {map, reportContext};
  }