make rollup only build one integration at at time

Author: lobsterkatie

packages/integrations/rollup.config.js

@@ -1,26 +1,22 @@
-import * as fs from 'fs';
-
 import commonjs from '@rollup/plugin-commonjs';
 
 import { insertAt, makeBaseBundleConfig, makeConfigVariants } from '../../rollup.config';
 
 const builds = [];
 
-const integrationSourceFiles = fs.readdirSync('./src').filter(file => file != 'index.ts');
+const file = process.env.INTEGRATION_FILE;
 
-integrationSourceFiles.forEach(file => {
-  const baseBundleConfig = makeBaseBundleConfig({
-    input: `src/${file}`,
-    isAddOn: true,
-    jsVersion: 'es5',
-    licenseTitle: '@sentry/integrations',
-    outputFileBase: `build/${file.replace('.ts', '')}`,
-  });
+const baseBundleConfig = makeBaseBundleConfig({
+  input: `src/${file}`,
+  isAddOn: true,
+  jsVersion: 'es5',
+  licenseTitle: '@sentry/integrations',
+  outputFileBase: `build/${file.replace('.ts', '')}`,
+});
 
-  // TODO We only need `commonjs` for localforage (used in the offline plugin). Once that's fixed, this can come out.
-  baseBundleConfig.plugins = insertAt(baseBundleConfig.plugins, -2, commonjs());
+// TODO We only need `commonjs` for localforage (used in the offline plugin). Once that's fixed, this can come out.
+baseBundleConfig.plugins = insertAt(baseBundleConfig.plugins, -2, commonjs());
 
-  builds.push(...makeConfigVariants(baseBundleConfig));
-});
+builds.push(...makeConfigVariants(baseBundleConfig));
 
 export default builds;