From 0c33465470fdbd61810439940c0a15ca15077399 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20Adel=C3=B6w?= <freben@gmail.com>
Date: Sat, 7 Dec 2024 11:22:57 +0100
Subject: [PATCH] implement single-item fetches to go by refs instead of
 filters
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Signed-off-by: Fredrik Adelöw <freben@gmail.com>
---
 .changeset/itchy-ravens-punch.md              |  5 ++++
 .../src/service/createRouter.test.ts          | 30 +++++++------------
 .../src/service/createRouter.ts               | 12 +++-----
 3 files changed, 19 insertions(+), 28 deletions(-)
 create mode 100644 .changeset/itchy-ravens-punch.md

diff --git a/.changeset/itchy-ravens-punch.md b/.changeset/itchy-ravens-punch.md
new file mode 100644
index 0000000000..7d4cb9cd92
--- /dev/null
+++ b/.changeset/itchy-ravens-punch.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend': patch
+---
+
+Implement `/entities/by-name/:kind/:namespace/:name` using `getEntitiesByRefs`
diff --git a/plugins/catalog-backend/src/service/createRouter.test.ts b/plugins/catalog-backend/src/service/createRouter.test.ts
index 0c1d16b525..e728017f0b 100644
--- a/plugins/catalog-backend/src/service/createRouter.test.ts
+++ b/plugins/catalog-backend/src/service/createRouter.test.ts
@@ -445,20 +445,15 @@ describe('createRouter readonly disabled', () => {
           namespace: 'ns',
         },
       };
-      entitiesCatalog.entities.mockResolvedValue({
-        entities: [entity],
-        pageInfo: { hasNextPage: false },
+      entitiesCatalog.entitiesBatch.mockResolvedValue({
+        items: [entity],
       });
 
       const response = await request(app).get('/entities/by-name/k/ns/n');
 
-      expect(entitiesCatalog.entities).toHaveBeenCalledTimes(1);
-      expect(entitiesCatalog.entities).toHaveBeenCalledWith({
-        filter: basicEntityFilter({
-          kind: 'k',
-          'metadata.namespace': 'ns',
-          'metadata.name': 'n',
-        }),
+      expect(entitiesCatalog.entitiesBatch).toHaveBeenCalledTimes(1);
+      expect(entitiesCatalog.entitiesBatch).toHaveBeenCalledWith({
+        entityRefs: ['k:ns/n'],
         credentials: mockCredentials.user(),
       });
       expect(response.status).toEqual(200);
@@ -466,20 +461,15 @@ describe('createRouter readonly disabled', () => {
     });
 
     it('responds with a 404 for missing entities', async () => {
-      entitiesCatalog.entities.mockResolvedValue({
-        entities: [],
-        pageInfo: { hasNextPage: false },
+      entitiesCatalog.entitiesBatch.mockResolvedValue({
+        items: [null],
       });
 
       const response = await request(app).get('/entities/by-name/b/d/c');
 
-      expect(entitiesCatalog.entities).toHaveBeenCalledTimes(1);
-      expect(entitiesCatalog.entities).toHaveBeenCalledWith({
-        filter: basicEntityFilter({
-          kind: 'b',
-          'metadata.namespace': 'd',
-          'metadata.name': 'c',
-        }),
+      expect(entitiesCatalog.entitiesBatch).toHaveBeenCalledTimes(1);
+      expect(entitiesCatalog.entitiesBatch).toHaveBeenCalledWith({
+        entityRefs: ['b:d/c'],
         credentials: mockCredentials.user(),
       });
       expect(response.status).toEqual(404);
diff --git a/plugins/catalog-backend/src/service/createRouter.ts b/plugins/catalog-backend/src/service/createRouter.ts
index 3a6dc82586..d70419c565 100644
--- a/plugins/catalog-backend/src/service/createRouter.ts
+++ b/plugins/catalog-backend/src/service/createRouter.ts
@@ -274,20 +274,16 @@ export async function createRouter(
       })
       .get('/entities/by-name/:kind/:namespace/:name', async (req, res) => {
         const { kind, namespace, name } = req.params;
-        const { entities } = await entitiesCatalog.entities({
-          filter: basicEntityFilter({
-            kind: kind,
-            'metadata.namespace': namespace,
-            'metadata.name': name,
-          }),
+        const { items } = await entitiesCatalog.entitiesBatch({
+          entityRefs: [stringifyEntityRef({ kind, namespace, name })],
           credentials: await httpAuth.credentials(req),
         });
-        if (!entities.length) {
+        if (!items[0]) {
           throw new NotFoundError(
             `No entity named '${name}' found, with kind '${kind}' in namespace '${namespace}'`,
           );
         }
-        res.status(200).json(entities[0]);
+        res.status(200).json(items[0]);
       })
       .get(
         '/entities/by-name/:kind/:namespace/:name/ancestry',