Merge pull request #13297 from swenhan/master

Fix in-doc search no result when title has stopwords

.changeset/heavy-ligers-laugh.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-search-backend-node': patch
+---
+
+Fixed bug in LunrSearchEngine where stopwords in title is causing in-doc search not working

plugins/search-backend-node/src/engines/LunrSearchEngine.test.ts

@@ -1092,3 +1092,123 @@ describe('parseHighlightFields', () => {
     });
   });
 });
+
+describe('stopword testing', () => {
+  let testLunrSearchEngine: SearchEngine;
+
+  beforeEach(() => {
+    testLunrSearchEngine = new LunrSearchEngine({ logger: getVoidLogger() });
+    jest.clearAllMocks();
+  });
+
+  it('test with stopword in title', async () => {
+    const mockDocuments = [
+      {
+        title: 'a home',
+        text: 'mary had a little lamb at home',
+        location: 'test/location',
+      },
+    ];
+
+    const indexer = await getActualIndexer(testLunrSearchEngine, 'test-index');
+
+    await TestPipeline.withSubject(indexer)
+      .withDocuments(mockDocuments)
+      .execute();
+
+    const mockedSearchResult = await testLunrSearchEngine.query({
+      term: 'mary',
+      filters: {
+        title: 'a home',
+      },
+    });
+
+    expect(mockedSearchResult).toMatchObject({
+      results: [
+        {
+          document: {
+            title: 'a home',
+            text: 'mary had a little lamb at home',
+            location: 'test/location',
+          },
+          rank: 1,
+        },
+      ],
+      nextPageCursor: undefined,
+    });
+  });
+
+  it('test with stopword connected with dash', async () => {
+    const mockDocuments = [
+      {
+        title: 'a-home',
+        text: 'mary had a little lamb at home',
+        location: 'test/location',
+      },
+    ];
+
+    const indexer = await getActualIndexer(testLunrSearchEngine, 'test-index');
+
+    await TestPipeline.withSubject(indexer)
+      .withDocuments(mockDocuments)
+      .execute();
+
+    const mockedSearchResult = await testLunrSearchEngine.query({
+      term: 'mary',
+      filters: {
+        title: 'a-home',
+      },
+    });
+
+    expect(mockedSearchResult).toMatchObject({
+      results: [
+        {
+          document: {
+            title: 'a-home',
+            text: 'mary had a little lamb at home',
+            location: 'test/location',
+          },
+          rank: 1,
+        },
+      ],
+      nextPageCursor: undefined,
+    });
+  });
+
+  it('test with only stop word in title', async () => {
+    const mockDocuments = [
+      {
+        title: 'a',
+        text: 'mary had a little lamb at home',
+        location: 'test/location',
+      },
+    ];
+
+    const indexer = await getActualIndexer(testLunrSearchEngine, 'test-index');
+
+    await TestPipeline.withSubject(indexer)
+      .withDocuments(mockDocuments)
+      .execute();
+
+    const mockedSearchResult = await testLunrSearchEngine.query({
+      term: 'mary',
+      filters: {
+        title: 'a',
+      },
+    });
+
+    expect(mockedSearchResult).toMatchObject({
+      results: [
+        {
+          document: {
+            title: 'a',
+            text: 'mary had a little lamb at home',
+            location: 'test/location',
+          },
+          rank: 1,
+        },
+      ],
+      nextPageCursor: undefined,
+    });
+  });
+});

plugins/search-backend-node/src/engines/LunrSearchEngine.ts

@@ -114,10 +114,16 @@ export class LunrSearchEngine implements SearchEngine {
 
             // Require that the given field has the given value
             if (['string', 'number', 'boolean'].includes(typeof value)) {
-              q.term(lunr.tokenizer(value?.toString()), {
-                presence: lunr.Query.presence.REQUIRED,
-                fields: [field],
-              });
+              q.term(
+                lunr
+                  .tokenizer(value?.toString())
+                  .map(lunr.stopWordFilter)
+                  .filter(element => element !== undefined),
+                {
+                  presence: lunr.Query.presence.REQUIRED,
+                  fields: [field],
+                },
+              );
             } else if (Array.isArray(value)) {
               // Illustrate how multi-value filters could work.
               // But warn that Lurn supports this poorly.