From 840a2687fe903d99308a1c7f956548b6fa8a2850 Mon Sep 17 00:00:00 2001
From: Alex Lorenzi <alorenzi@spotify.com>
Date: Wed, 12 Feb 2025 18:22:44 -0500
Subject: [PATCH] This is a better fix. Docs for Azure/fetch-event-source
 mention you should re-throw the error in the onerror function to stop
 operation

Signed-off-by: Alex Lorenzi <alorenzi@spotify.com>
---
 .../src/service/router.test.ts                 | 18 ++----------------
 plugins/techdocs-backend/src/service/router.ts | 12 ++++--------
 plugins/techdocs/src/client.ts                 |  1 +
 3 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/plugins/techdocs-backend/src/service/router.test.ts b/plugins/techdocs-backend/src/service/router.test.ts
index 21b6dd5554..c74167552d 100644
--- a/plugins/techdocs-backend/src/service/router.test.ts
+++ b/plugins/techdocs-backend/src/service/router.test.ts
@@ -164,14 +164,7 @@ describe('createRouter', () => {
           .set('accept', 'text/event-stream')
           .send();
 
-        expect(response.status).toBe(200);
-        expect(response.get('content-type')).toBe('text/event-stream');
-        expect(response.text).toEqual(
-          `event: error
-data: "Entity not found"
-
-`,
-        );
+        expect(response.status).toBe(404);
       });
 
       it('should return not found if entity has no uid', async () => {
@@ -186,14 +179,7 @@ data: "Entity not found"
           .set('accept', 'text/event-stream')
           .send();
 
-        expect(response.status).toBe(200);
-        expect(response.get('content-type')).toBe('text/event-stream');
-        expect(response.text).toEqual(
-          `event: error
-data: "Entity metadata UID missing"
-
-`,
-        );
+        expect(response.status).toBe(404);
       });
 
       it('should not check for an update when shouldBuild returns false', async () => {
diff --git a/plugins/techdocs-backend/src/service/router.ts b/plugins/techdocs-backend/src/service/router.ts
index 301bc43755..b99579e0eb 100644
--- a/plugins/techdocs-backend/src/service/router.ts
+++ b/plugins/techdocs-backend/src/service/router.ts
@@ -242,18 +242,14 @@ export async function createRouter(
       targetPluginId: 'catalog',
     });
 
-    const responseHandler: DocsSynchronizerSyncOpts = createEventStream(res);
-
     const entity = await entityLoader.load({ kind, namespace, name }, token);
+
     if (!entity?.metadata?.uid) {
-      responseHandler.error(
-        new NotFoundError(
-          entity ? 'Entity metadata UID missing' : 'Entity not found',
-        ),
-      );
-      return;
+      throw new NotFoundError('Entity metadata UID missing');
     }
 
+    const responseHandler: DocsSynchronizerSyncOpts = createEventStream(res);
+
     // By default, techdocs-backend will only try to build documentation for an entity if techdocs.builder is set to
     // 'local'. If set to 'external', it will assume that an external process (e.g. CI/CD pipeline
     // of the repository) is responsible for building and publishing documentation to the storage provider.
diff --git a/plugins/techdocs/src/client.ts b/plugins/techdocs/src/client.ts
index d00be2a01f..9ea753b1e6 100644
--- a/plugins/techdocs/src/client.ts
+++ b/plugins/techdocs/src/client.ts
@@ -236,6 +236,7 @@ export class TechDocsStorageClient implements TechDocsStorageApi {
         onerror(err) {
           ctrl.abort();
           reject(err);
+          throw err; // rethrow to stop the operation
         },
       });
     });