export function runHermesEmitBinaryCommand()

in src/commands/codepush/lib/react-native-utils.ts [351:465]
92 lines of code
12 McCabe index (conditional complexity)

export function runHermesEmitBinaryCommand(
  bundleName: string,
  outputFolder: string,
  sourcemapOutput: string,
  extraHermesFlags: string[]
): Promise<void> {
  const hermesArgs: string[] = [];
  const envNodeArgs: string = process.env.CODE_PUSH_NODE_ARGS;

  if (typeof envNodeArgs !== "undefined") {
    Array.prototype.push.apply(hermesArgs, envNodeArgs.trim().split(/\s+/));
  }

  Array.prototype.push.apply(hermesArgs, [
    "-emit-binary",
    "-out",
    path.join(outputFolder, bundleName + ".hbc"),
    path.join(outputFolder, bundleName),
    ...extraHermesFlags,
  ]);

  if (sourcemapOutput) {
    hermesArgs.push("-output-source-map");
  }

  if (!isDebug()) {
    hermesArgs.push("-w");
  }

  out.text(chalk.cyan("Converting JS bundle to byte code via Hermes, running command:\n"));
  const hermesCommand = getHermesCommand();
  const hermesProcess = childProcess.spawn(hermesCommand, hermesArgs);
  out.text(`${hermesCommand} ${hermesArgs.join(" ")}`);

  return new Promise<void>((resolve, reject) => {
    hermesProcess.stdout.on("data", (data: Buffer) => {
      out.text(data.toString().trim());
    });

    hermesProcess.stderr.on("data", (data: Buffer) => {
      console.error(data.toString().trim());
    });

    hermesProcess.on("close", (exitCode: number) => {
      if (exitCode) {
        reject(new Error(`"hermes" command exited with code ${exitCode}.`));
      }
      // Copy HBC bundle to overwrite JS bundle
      const source = path.join(outputFolder, bundleName + ".hbc");
      const destination = path.join(outputFolder, bundleName);
      fs.copyFile(source, destination, (err) => {
        if (err) {
          console.error(err);
          reject(new Error(`Copying file ${source} to ${destination} failed. "hermes" previously exited with code ${exitCode}.`));
        }
        fs.unlink(source, (err) => {
          if (err) {
            console.error(err);
            reject(err);
          }
          resolve(null as void);
        });
      });
    });
  }).then(() => {
    if (!sourcemapOutput) {
      // skip source map compose if source map is not enabled
      return;
    }

    const composeSourceMapsPath = getComposeSourceMapsPath();
    if (!composeSourceMapsPath) {
      throw new Error("react-native compose-source-maps.js scripts is not found");
    }

    const jsCompilerSourceMapFile = path.join(outputFolder, bundleName + ".hbc" + ".map");
    if (!fs.existsSync(jsCompilerSourceMapFile)) {
      throw new Error(`sourcemap file ${jsCompilerSourceMapFile} is not found`);
    }

    return new Promise((resolve, reject) => {
      const composeSourceMapsArgs = [sourcemapOutput, jsCompilerSourceMapFile, "-o", sourcemapOutput];

      // https://github.com/facebook/react-native/blob/master/react.gradle#L211
      // https://github.com/facebook/react-native/blob/master/scripts/react-native-xcode.sh#L178
      // packager.sourcemap.map + hbc.sourcemap.map = sourcemap.map
      const composeSourceMapsProcess = childProcess.spawn(composeSourceMapsPath, composeSourceMapsArgs);
      out.text(`${composeSourceMapsPath} ${composeSourceMapsArgs.join(" ")}`);

      composeSourceMapsProcess.stdout.on("data", (data: Buffer) => {
        out.text(data.toString().trim());
      });

      composeSourceMapsProcess.stderr.on("data", (data: Buffer) => {
        console.error(data.toString().trim());
      });

      composeSourceMapsProcess.on("close", (exitCode: number) => {
        if (exitCode) {
          reject(new Error(`"compose-source-maps" command exited with code ${exitCode}.`));
        }

        // Delete the HBC sourceMap, otherwise it will be included in 'code-push' bundle as well
        fs.unlink(jsCompilerSourceMapFile, (err) => {
          if (err) {
            console.error(err);
            reject(err);
          }

          resolve(null);
        });
      });
    });
  });
}