fix: ignore mapped metadata sheet with not default

src/steps/fetch-mapped-metadata.js

@@ -38,8 +38,12 @@ export default async function fetchMappedMetadata(state) {
     } catch (e) {
       throw new PipelineStatusError(500, `failed parsing of ${metadataPath}: ${e.message}`);
     }
-
     const { data } = json.default ?? json;
+    if (!data) {
+      state.log.info(`default sheet missing in ${metadataPath}`);
+      return;
+    }
+
     if (!Array.isArray(data)) {
       throw new PipelineStatusError(500, `failed loading of ${metadataPath}: data must be an array`);
     }

test/steps/fetch-mapped-metadata.test.js

@@ -15,6 +15,7 @@ import { PipelineStatusError } from '../../src/index.js';
 import { StaticS3Loader } from '../StaticS3Loader.js';
 import fetchMappedMetadata from '../../src/steps/fetch-mapped-metadata.js';
 import { FileS3Loader } from '../FileS3Loader.js';
+import { Modifiers } from '../../src/utils/modifiers.js';
 
 describe('Fetch Mapped Metadata', () => {
   it('parses KV sheet', async () => {
@@ -56,7 +57,7 @@ describe('Fetch Mapped Metadata', () => {
     await assert.rejects(promise, new PipelineStatusError(500, 'failed parsing of /mapped/metadata.json: Unexpected token \'h\', "this is no json!" is not valid JSON'));
   });
 
-  it('throws error on metadata with no data array', async () => {
+  it('throws error on metadata with invalid data array', async () => {
     const promise = fetchMappedMetadata({
       log: console,
       contentBusId: 'foo-id',
@@ -68,13 +69,33 @@ describe('Fetch Mapped Metadata', () => {
       s3Loader: new StaticS3Loader()
         .reply('helix-content-bus', 'foo-id/live/mapped/metadata.json', {
           status: 200,
-          body: '{}',
+          body: '{ "data": "42" }',
           headers: new Map(),
         }),
     });
     await assert.rejects(promise, new PipelineStatusError(500, 'failed loading of /mapped/metadata.json: data must be an array'));
   });
 
+  it('ignores metadata with no data array', async () => {
+    const state = {
+      log: console,
+      contentBusId: 'foo-id',
+      partition: 'live',
+      mapped: true,
+      info: {
+        path: '/mapped',
+      },
+      s3Loader: new StaticS3Loader()
+        .reply('helix-content-bus', 'foo-id/live/mapped/metadata.json', {
+          status: 200,
+          body: '{}',
+          headers: new Map(),
+        }),
+    };
+    await fetchMappedMetadata(state);
+    assert.strictEqual(state.mappedMetadata, Modifiers.EMPTY);
+  });
+
   it('throws error on generic error', async () => {
     const promise = fetchMappedMetadata({
       log: console,