fix: stop nameMatchBonus awarding a spurious +10 on a whitespace-only query

__tests__/context-ranking.test.ts

@@ -16,7 +16,7 @@ import * as path from 'path';
 import * as os from 'os';
 import CodeGraph from '../src/index';
 import { LOW_CONFIDENCE_MARKER } from '../src/context';
-import { isDistinctiveIdentifier, scorePathRelevance, deriveProjectNameTokens } from '../src/search/query-utils';
+import { isDistinctiveIdentifier, scorePathRelevance, deriveProjectNameTokens, nameMatchBonus } from '../src/search/query-utils';
 
 describe('isDistinctiveIdentifier', () => {
   it('treats plain dictionary words as non-distinctive', () => {
@@ -39,6 +39,26 @@ describe('isDistinctiveIdentifier', () => {
   });
 });
 
+// An empty / whitespace-only query has no name to match, so the bonus must be
+// 0. Before the guard, `queryLower` collapsed to '' and `nameLower.startsWith('')`
+// (always true) awarded a spurious flat +10 to every node. This is reachable via
+// `searchNodes('   ')`, where the rescoring guard `text || query` passes a
+// whitespace-only query through to nameMatchBonus.
+describe('nameMatchBonus empty/whitespace query', () => {
+  it('returns 0 for an empty query', () => {
+    expect(nameMatchBonus('authenticate', '')).toBe(0);
+  });
+
+  it('returns 0 for a whitespace-only query', () => {
+    expect(nameMatchBonus('authenticate', '   ')).toBe(0);
+    expect(nameMatchBonus('anything', '\t\n')).toBe(0);
+  });
+
+  it('still scores a real query (exact match unaffected by the guard)', () => {
+    expect(nameMatchBonus('authenticate', 'authenticate')).toBe(80);
+  });
+});
+
 // A single PascalCase query word (notably a project name a user naturally
 // includes) splits into sub-tokens that all match the SAME path segment; summed
 // per sub-token it boosted that path 4×, burying the rest of the query's stack

src/search/query-utils.ts

@@ -343,6 +343,16 @@ function matchesNonProductionDir(lowerPath: string): boolean {
 export function nameMatchBonus(nodeName: string, query: string): number {
   const nameLower = nodeName.toLowerCase();
 
+  // Full query as a single token (for compound identifiers like "CacheBuilder")
+  const queryLower = query.replace(/[\s]+/g, '').toLowerCase();
+
+  // An empty / whitespace-only query carries no name to match against. Bail
+  // before the `startsWith` check below, since `anyString.startsWith('')` is
+  // always true and would otherwise award a spurious flat +10 to every node
+  // (reachable via `searchNodes('   ')`, where the rescoring guard `text ||
+  // query` lets a whitespace-only query through).
+  if (!queryLower) return 0;
+
   // Split query into word-level terms (handles "CacheBuilder build" → ["cache","builder","build"])
   const rawTerms = query
     .replace(/([a-z])([A-Z])/g, '$1 $2')
@@ -353,9 +363,6 @@ export function nameMatchBonus(nodeName: string, query: string): number {
   // Also keep original space-separated tokens for exact-term matching
   const queryTokens = query.split(/\s+/).map(t => t.toLowerCase()).filter(t => t.length >= 2);
 
-  // Full query as a single token (for compound identifiers like "CacheBuilder")
-  const queryLower = query.replace(/[\s]+/g, '').toLowerCase();
-
   // Exact match: query exactly equals the node name
   if (nameLower === queryLower) return 80;