feat(remix): Add instrumentation step for Express server adapters.

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+- feat(remix): Add instrumentation step for Express server adapters (#504)s
+
 ## 3.19.0
 
 - feat(nextjs): Add instructions on how to set auth token in CI (#511)

src/remix/codemods/express-server.ts

@@ -0,0 +1,197 @@
+// @ts-expect-error - clack is ESM and TS complains about that. It works though
+import clack from '@clack/prompts';
+import chalk from 'chalk';
+import * as recast from 'recast';
+import { visit } from 'ast-types';
+import {
+  ASTNode,
+  ProxifiedImportItem,
+  generateCode,
+  loadFile,
+  writeFile,
+  // @ts-expect-error - magicast is ESM and TS complains about that. It works though
+} from 'magicast';
+import type { Program } from '@babel/types';
+import * as fs from 'fs';
+
+import { getInitCallInsertionIndex, hasSentryContent } from '../utils';
+import { findFile } from '../../utils/ast-utils';
+
+// Find `loadViteServerBuild` or `unstable_loadViteServerBuild` call inside an arrow function
+// and replace it with await loadViteServerBuild.
+// For context, see: https://github.com/getsentry/sentry-javascript/issues/9500
+export function updateViteBuildParameter(node: ASTNode) {
+  const hasViteConfig = findFile('vite.config');
+
+  if (!hasViteConfig) {
+    return;
+  }
+
+  visit(node, {
+    visitArrowFunctionExpression(path) {
+      if (
+        path.value.body.type === 'CallExpression' &&
+        path.value.body.callee.type === 'Identifier' &&
+        (path.value.body.callee.name === 'unstable_loadViteServerBuild' ||
+          path.value.body.callee.name === 'loadViteServerBuild')
+      ) {
+        // Replace the arrow function with a call to await loadViteServerBuild
+        path.replace(recast.types.builders.awaitExpression(path.value.body));
+      }
+
+      this.traverse(path);
+    },
+  });
+}
+
+// Try to find the Express server implementation that contains `createRequestHandler` from `@remix-run/express`
+export async function findCustomExpressServerImplementation() {
+  const possiblePaths = [
+    'server',
+    'server/index',
+    'app/server',
+    'app/server/index',
+  ];
+
+  for (const filePath of possiblePaths) {
+    const filename = findFile(filePath);
+
+    if (!filename) {
+      continue;
+    }
+
+    const fileStat = fs.statSync(filename);
+
+    if (!fileStat.isFile()) {
+      continue;
+    }
+
+    const fileMod = await loadFile(filename);
+    const createRequestHandlerImport = fileMod.imports.$items.find(
+      (imp) =>
+        imp.from === '@remix-run/express' &&
+        imp.imported === 'createRequestHandler',
+    );
+
+    if (createRequestHandlerImport) {
+      return filename;
+    }
+  }
+
+  return null;
+}
+
+// Wrap createRequestHandler with `wrapExpressCreateRequestHandler` from `@sentry/remix`
+export async function instrumentExpressCreateRequestHandler(
+  expressServerPath: string,
+): Promise<boolean> {
+  const originalExpressServerMod = await loadFile(expressServerPath);
+
+  if (
+    hasSentryContent(
+      generateCode(originalExpressServerMod.$ast).code,
+      originalExpressServerMod.$code,
+    )
+  ) {
+    clack.log.warn(
+      `Express server in ${chalk.cyan(
+        expressServerPath,
+      )} already has Sentry instrumentation. Skipping.`,
+    );
+
+    return false;
+  }
+
+  originalExpressServerMod.imports.$add({
+    from: '@sentry/remix',
+    imported: 'wrapExpressCreateRequestHandler',
+    local: 'wrapExpressCreateRequestHandler',
+  });
+
+  const createRequestHandlerImport =
+    originalExpressServerMod.imports.$items.find(
+      (imp) =>
+        imp.from === '@remix-run/express' &&
+        imp.imported === 'createRequestHandler',
+    );
+
+  visit(originalExpressServerMod.$ast, {
+    visitIdentifier(path) {
+      if (
+        path.value.name === 'createRequestHandler' &&
+        path.parentPath.value.type === 'CallExpression'
+      ) {
+        path.value.name = 'sentryCreateRequestHandler';
+      }
+
+      this.traverse(path);
+    },
+  });
+
+  // Insert the const declaration right after the imports
+  // Where we want to insert the const declaration is the same as where we would want to insert the init call.
+  const insertionIndex = getInitCallInsertionIndex(
+    originalExpressServerMod.$ast as Program,
+  );
+
+  const createRequestHandlerConst = wrapCreateRequestHandlerWithSentry(
+    createRequestHandlerImport,
+  );
+
+  if (!createRequestHandlerConst) {
+    // Todo: throw error
+  }
+
+  (originalExpressServerMod.$ast as Program).body.splice(
+    insertionIndex,
+    0,
+    // @ts-expect-error - string works here because the AST is proxified by magicast
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
+    createRequestHandlerConst,
+  );
+
+  // Update the Vite build parameter to await loadViteServerBuild if everything goes well.
+  // This should be the last thing we do.
+  updateViteBuildParameter(originalExpressServerMod.$ast);
+
+  try {
+    await writeFile(originalExpressServerMod.$ast, expressServerPath);
+
+    clack.log.info(
+      `Successfully instrumented Express server in ${chalk.cyan(
+        expressServerPath,
+      )}.`,
+    );
+  } catch (e) {
+    clack.log.warn(
+      `Could not write to Express server in ${chalk.cyan(expressServerPath)}.`,
+    );
+
+    throw e;
+  }
+
+  return true;
+}
+
+// Wrap `createRequestHandler` with `wrapExpressCreateRequestHandler` and set const name to `sentryCreateRequestHandler`
+export function wrapCreateRequestHandlerWithSentry(
+  createRequestHandlerImport: ProxifiedImportItem | undefined,
+) {
+  if (!createRequestHandlerImport) {
+    return;
+  }
+
+  const createRequestHandler = createRequestHandlerImport.local;
+
+  const wrapCreateRequestHandler = recast.types.builders.callExpression(
+    recast.types.builders.identifier('wrapExpressCreateRequestHandler'),
+    [recast.types.builders.identifier(createRequestHandler)],
+  );
+
+  return recast.types.builders.variableDeclaration('const', [
+    recast.types.builders.variableDeclarator(
+      recast.types.builders.identifier('sentryCreateRequestHandler'),
+      wrapCreateRequestHandler,
+    ),
+  ]);
+}

src/remix/remix-wizard.ts

@@ -23,6 +23,7 @@ import {
   isRemixV2,
   loadRemixConfig,
   runRemixReveal,
+  instrumentExpressServer,
 } from './sdk-setup';
 import { debug } from '../utils/debug';
 import { traceStep, withTelemetry } from '../telemetry';
@@ -152,6 +153,25 @@ async function runRemixWizardWithTelemetry(
     }
   });
 
+  await traceStep('Instrument custom Express server', async () => {
+    try {
+      const hasExpressAdapter = hasPackageInstalled(
+        '@remix-run/express',
+        packageJson,
+      );
+
+      if (!hasExpressAdapter) {
+        return;
+      }
+
+      await instrumentExpressServer();
+    } catch (e) {
+      clack.log.warn(`Could not instrument custom Express server.
+  Please do it manually using instructions from https://docs.sentry.io/platforms/javascript/guides/remix/manual-setup/#custom-express-server`);
+      debug(e);
+    }
+  });
+
   clack.outro(`
 ${chalk.green(
   'Sentry has been successfully configured for your Remix project.',

src/remix/sdk-setup.ts

@@ -22,6 +22,10 @@ import { getInitCallInsertionIndex, hasSentryContent } from './utils';
 import { instrumentRootRouteV1 } from './codemods/root-v1';
 import { instrumentRootRouteV2 } from './codemods/root-v2';
 import { instrumentHandleError } from './codemods/handle-error';
+import {
+  findCustomExpressServerImplementation,
+  instrumentExpressCreateRequestHandler,
+} from './codemods/express-server';
 import { getPackageDotJson } from '../utils/clack-utils';
 
 export type PartialRemixConfig = {
@@ -347,3 +351,16 @@ export async function initializeSentryOnEntryServer(
     )}.`,
   );
 }
+
+export async function instrumentExpressServer() {
+  const expressServerPath = await findCustomExpressServerImplementation();
+
+  if (!expressServerPath) {
+    clack.log.warn(
+      `Could not find custom Express server implementation. Please instrument it manually.`,
+    );
+    return;
+  }
+
+  await instrumentExpressCreateRequestHandler(expressServerPath);
+}