Initial import from garrytan/gstack@026751e (main snapshot via local relay)

Source: https://github.com/garrytan/gstack/commit/026751e

test/helpers/session-runner.test.ts

@@ -0,0 +1,96 @@
+import { describe, test, expect } from 'bun:test';
+import { parseNDJSON } from './session-runner';
+
+// Fixture: minimal NDJSON session (system init, assistant with tool_use, tool result, assistant text, result)
+const FIXTURE_LINES = [
+  '{"type":"system","subtype":"init","session_id":"test-123"}',
+  '{"type":"assistant","message":{"content":[{"type":"tool_use","id":"tu1","name":"Bash","input":{"command":"echo hello"}}]}}',
+  '{"type":"user","tool_use_result":{"tool_use_id":"tu1","stdout":"hello\\n","stderr":""}}',
+  '{"type":"assistant","message":{"content":[{"type":"text","text":"The command printed hello."}]}}',
+  '{"type":"assistant","message":{"content":[{"type":"text","text":"Let me also read a file."},{"type":"tool_use","id":"tu2","name":"Read","input":{"file_path":"/tmp/test"}}]}}',
+  '{"type":"result","subtype":"success","total_cost_usd":0.05,"num_turns":3,"usage":{"input_tokens":100,"output_tokens":50},"result":"Done."}',
+];
+
+describe('parseNDJSON', () => {
+  test('parses valid NDJSON with system + assistant + result events', () => {
+    const parsed = parseNDJSON(FIXTURE_LINES);
+    expect(parsed.transcript).toHaveLength(6);
+    expect(parsed.transcript[0].type).toBe('system');
+    expect(parsed.transcript[5].type).toBe('result');
+  });
+
+  test('extracts tool calls from assistant.message.content[].type === tool_use', () => {
+    const parsed = parseNDJSON(FIXTURE_LINES);
+    expect(parsed.toolCalls).toHaveLength(2);
+    expect(parsed.toolCalls[0]).toEqual({
+      tool: 'Bash',
+      input: { command: 'echo hello' },
+      output: '',
+    });
+    expect(parsed.toolCalls[1]).toEqual({
+      tool: 'Read',
+      input: { file_path: '/tmp/test' },
+      output: '',
+    });
+    expect(parsed.toolCallCount).toBe(2);
+  });
+
+  test('skips malformed lines without throwing', () => {
+    const lines = [
+      '{"type":"system"}',
+      'this is not json',
+      '{"type":"assistant","message":{"content":[{"type":"text","text":"ok"}]}}',
+      '{incomplete json',
+      '{"type":"result","subtype":"success","result":"done"}',
+    ];
+    const parsed = parseNDJSON(lines);
+    expect(parsed.transcript).toHaveLength(3); // system, assistant, result
+    expect(parsed.resultLine?.subtype).toBe('success');
+  });
+
+  test('skips empty and whitespace-only lines', () => {
+    const lines = [
+      '',
+      '  ',
+      '{"type":"system"}',
+      '\t',
+      '{"type":"result","subtype":"success","result":"ok"}',
+    ];
+    const parsed = parseNDJSON(lines);
+    expect(parsed.transcript).toHaveLength(2);
+  });
+
+  test('extracts resultLine from type: "result" event', () => {
+    const parsed = parseNDJSON(FIXTURE_LINES);
+    expect(parsed.resultLine).not.toBeNull();
+    expect(parsed.resultLine.subtype).toBe('success');
+    expect(parsed.resultLine.total_cost_usd).toBe(0.05);
+    expect(parsed.resultLine.num_turns).toBe(3);
+    expect(parsed.resultLine.result).toBe('Done.');
+  });
+
+  test('counts turns correctly — one per assistant event, not per text block', () => {
+    const parsed = parseNDJSON(FIXTURE_LINES);
+    // 3 assistant events in fixture (tool_use, text, text+tool_use)
+    expect(parsed.turnCount).toBe(3);
+  });
+
+  test('handles empty input', () => {
+    const parsed = parseNDJSON([]);
+    expect(parsed.transcript).toHaveLength(0);
+    expect(parsed.resultLine).toBeNull();
+    expect(parsed.turnCount).toBe(0);
+    expect(parsed.toolCallCount).toBe(0);
+    expect(parsed.toolCalls).toHaveLength(0);
+  });
+
+  test('handles assistant event with no content array', () => {
+    const lines = [
+      '{"type":"assistant","message":{}}',
+      '{"type":"assistant"}',
+    ];
+    const parsed = parseNDJSON(lines);
+    expect(parsed.turnCount).toBe(2);
+    expect(parsed.toolCalls).toHaveLength(0);
+  });
+});