Merge pull request #6058 from oOntheway/master

Searching for things like "World" in "Hello World." returns no results.

.changeset/cyan-drinks-dream.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-search-backend-node': patch
+---
+
+Improved the quality of free text searches in LunrSearchEngine.

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

@@ -191,6 +191,72 @@ describe('LunrSearchEngine', () => {
       });
     });
 
+    it('should perform search query with trailing punctuation and return search results on match (trimming)', async () => {
+      const mockDocuments = [
+        {
+          title: 'testTitle',
+          text: 'Hello World.',
+          location: 'test/location',
+        },
+      ];
+
+      // Mock indexing of 1 document
+      testLunrSearchEngine.index('test-index', mockDocuments);
+
+      // Perform search query
+      const mockedSearchResult = await testLunrSearchEngine.query({
+        term: 'World',
+        filters: {},
+        pageCursor: '',
+      });
+
+      // Should return 1 result as we are mocking the indexing of 1 document with match on the title field
+      expect(mockedSearchResult).toMatchObject({
+        results: [
+          {
+            document: {
+              title: 'testTitle',
+              text: 'Hello World.',
+              location: 'test/location',
+            },
+          },
+        ],
+      });
+    });
+
+    it('should perform search query by similar words and return search results on match (stemming)', async () => {
+      const mockDocuments = [
+        {
+          title: 'testTitle',
+          text: 'Searching',
+          location: 'test/location',
+        },
+      ];
+
+      // Mock indexing of 1 document
+      testLunrSearchEngine.index('test-index', mockDocuments);
+
+      // Perform search query
+      const mockedSearchResult = await testLunrSearchEngine.query({
+        term: 'Search',
+        filters: {},
+        pageCursor: '',
+      });
+
+      // Should return 1 result as we are mocking the indexing of 1 document with match on the title field
+      expect(mockedSearchResult).toMatchObject({
+        results: [
+          {
+            document: {
+              title: 'testTitle',
+              text: 'Searching',
+              location: 'test/location',
+            },
+          },
+        ],
+      });
+    });
+
     it('should perform search query and return search results on match with filters', async () => {
       const mockDocuments = [
         {

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

@@ -90,6 +90,10 @@ export class LunrSearchEngine implements SearchEngine {
 
   index(type: string, documents: IndexableDocument[]): void {
     const lunrBuilder = new lunr.Builder();
+
+    lunrBuilder.pipeline.add(lunr.trimmer, lunr.stopWordFilter, lunr.stemmer);
+    lunrBuilder.searchPipeline.add(lunr.stemmer);
+
     // Make this lunr index aware of all relevant fields.
     Object.keys(documents[0]).forEach(field => {
       lunrBuilder.field(field);