[api] Add Sentry (#3597)

* [api] Add Sentry

* Use function name

* Add test error

* Revert "Add test error"

This reverts commit 39cf8a61dad9fcdcb616e418a0deb6ffe9e04ea9.

* Revert "Revert "Add test error""

This reverts commit c718f201da9d80743319ac87e0d4560e718fff53.

* Add logging

* Revert "Add logging"

This reverts commit 39cd46c8bbeef9024e71fe70478068480a51545b.

* Revert "Revert "Revert "Add test error"""

This reverts commit e6f63ee21fabb4ac8fc065b74281dbcdf5811216.

* Ignore .env

* Use init function for Sentry inline

api/_lib/util/assert-env.ts

@@ -0,0 +1,9 @@
+export function assertEnv(name: string) {
+  const value = process.env[name];
+
+  if (!value) {
+    throw new Error(`Missing env "${name}"`);
+  }
+
+  return value;
+}

api/_lib/util/error-handler.ts

@@ -0,0 +1,43 @@
+import { init, captureException, withScope } from '@sentry/node';
+import { assertEnv } from './assert-env';
+
+const serviceName = 'api-frameworks';
+
+let sentryInitDone = false;
+
+function initSentry() {
+  if (sentryInitDone) {
+    return;
+  }
+
+  sentryInitDone = true;
+
+  init({
+    dsn: assertEnv('SENTRY_DSN'),
+    environment: process.env.NODE_ENV || 'production',
+    release: `${serviceName}`,
+  });
+}
+
+export function errorHandler(error: Error, extras?: { [key: string]: any }) {
+  if (!process.env.SENTRY_DSN) {
+    return;
+  }
+
+  initSentry();
+
+  try {
+    withScope(scope => {
+      scope.setTag('service', serviceName);
+      scope.setTag('function_name', assertEnv('AWS_LAMBDA_FUNCTION_NAME'));
+
+      for (const [k, v] of Object.entries(extras)) {
+        scope.setExtra(k, v);
+      }
+
+      captureException(error);
+    });
+  } catch (e) {
+    console.error(`Failed to report error to Sentry: ${e}`);
+  }
+}

api/_lib/util/with-api-handler.ts

@@ -1,4 +1,5 @@
 import { NowRequest, NowResponse } from '@now/node';
+import { errorHandler } from './error-handler';
 
 type Handler = (req: NowRequest, res: NowResponse) => Promise<any>;
 
@@ -24,6 +25,20 @@ export function withApiHandler(handler: Handler): Handler {
       });
     }
 
-    return handler(req, res);
+    try {
+      const result = await handler(req, res);
+      return result;
+    } catch (error) {
+      errorHandler(error, {
+        url: req.url,
+      });
+
+      return res.status(500).json({
+        error: {
+          code: 'unexpected_error',
+          message: 'An unexpected error occurred.',
+        },
+      });
+    }
   };
 }