fix(context): Fix snapshot recovery across sessions. (#26939)

2026-07-16 04:50:29 -07:00 · 2026-05-18 09:44:59 -07:00
parent 9d01958cdb
commit 055e0f6452
57 changed files with 3143 additions and 751 deletions
@@ -0,0 +1,110 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { ContextGraphMapper } from './mapper.js';
+import type { HistoryTurn } from '../../core/agentChatHistory.js';
+import { hardenHistory } from '../../utils/historyHardening.js';
+
+describe('ContextGraphMapper (Round-Trip Fidelity)', () => {
+  it('should flawlessly round-trip a complex history containing parallel tool calls and responses', () => {
+    // 1. Define a complex, worst-case scenario history
+    const originalHistory: HistoryTurn[] = [
+      {
+        id: 'system_prompt_id',
+        content: {
+          role: 'user',
+          parts: [{ text: '<session_context>\nSystem Prompt here' }],
+        },
+      },
+      {
+        id: 'user_turn_1',
+        content: {
+          role: 'user',
+          parts: [{ text: 'Please read file A and file B at the same time.' }],
+        },
+      },
+      {
+        id: 'model_turn_1',
+        content: {
+          role: 'model',
+          parts: [
+            { text: 'I will read both files concurrently.' },
+            {
+              functionCall: {
+                id: 'call_A',
+                name: 'read_file',
+                args: { path: 'A.txt' },
+              },
+              thoughtSignature: 'synthetic_sig_xyz',
+            },
+            {
+              functionCall: {
+                id: 'call_B',
+                name: 'read_file',
+                args: { path: 'B.txt' },
+              },
+            },
+          ],
+        },
+      },
+      // Note: GeminiChat records these as separate sequential user turns initially
+      {
+        id: 'tool_resp_B_id',
+        content: {
+          role: 'user',
+          parts: [
+            {
+              functionResponse: {
+                id: 'call_B',
+                name: 'read_file',
+                response: { content: 'File B' },
+              },
+            },
+          ],
+        },
+      },
+      {
+        id: 'tool_resp_A_id',
+        content: {
+          role: 'user',
+          parts: [
+            {
+              functionResponse: {
+                id: 'call_A',
+                name: 'read_file',
+                response: { content: 'File A' },
+              },
+            },
+          ],
+        },
+      },
+    ];
+
+    // 2. We harden the original history first. The core agent loop feeds the hardener the pure history.
+    // We want our round-tripped history to match what the hardener WOULD have produced natively.
+    const hardenedOriginal = hardenHistory(originalHistory);
+
+    // 3. Translate History -> Graph
+    const mapper = new ContextGraphMapper();
+    // Simulate the HistoryObserver capturing the push
+    const nodes = mapper.applyEvent({
+      type: 'SYNC_FULL',
+      payload: originalHistory,
+    });
+
+    // 4. Translate Graph -> History
+    const reconstructedHistory = mapper.fromGraph(nodes);
+
+    // 5. Harden the reconstructed history (as the ContextManager does before sending to API)
+    const hardenedReconstructed = hardenHistory(reconstructedHistory);
+
+    // 6. Assert Absolute Equality
+    // The round-trip through the Context Graph and Hardener must exactly equal
+    // the original history put through the Hardener.
+    expect(hardenedReconstructed).toEqual(hardenedOriginal);
+  });
+});