expo-eas-observe/plugin/src/index.ts

Expo module that exposes various app metrics and sends them to EAS Observe

import { withMainApplication, type ConfigPlugin } from 'expo/config-plugins';

const withAndroidAppMetrics: ConfigPlugin = (config) => {
  return withMainApplication(config, (config) => {
    const mainApplication = config.modResults;

    const importsMod = addImports(
      mainApplication.contents,
      ['expo.modules.appmetrics.appstartup.AppStartupManager'],
      false
    );

    let contents = importsMod;
    if (!mainApplication.contents.includes('AppStartupManager.markOnCreate()')) {
      contents = appendMarkOnCreate(contents);
    }

    return {
      ...config,
      modResults: {
        ...config.modResults,
        contents,
      },
    };
  });
};

// Copied from https://github.com/expo/expo/blob/main/packages/expo-web-browser/plugin/src/utils.ts
function addImports(source: string, imports: string[], isJava: boolean): string {
  const lines = source.split('\n');
  const lineIndexWithPackageDeclaration = lines.findIndex((line) => line.match(/^package .*;?$/));
  for (const javaImport of imports) {
    if (!source.includes(javaImport)) {
      const importStatement = `import ${javaImport}${isJava ? ';' : ''}`;
      lines.splice(lineIndexWithPackageDeclaration + 2, 0, importStatement);
    }
  }
  return lines.join('\n');
}

function appendMarkOnCreate(source: string): string {
  // $1 includes indentation
  return source.replace(
    /^(\s*)super\.onCreate\(\)$/m,
    '$1super.onCreate()\n$1AppStartupManager.markOnCreate()'
  );
}

export default withAndroidAppMetrics;