test(lint): reduce warning debt in selected test suites

docs/plans/analysis/2026-02-16-codebase-audit-report.md

@@ -28,7 +28,7 @@ Current health snapshot:
 - `pnpm typecheck`: passing
 - `pnpm build`: passing
 - `pnpm test:run`: passing (`140/140` files, `1773/1773` tests)
-- `pnpm lint`: passing with warnings only (`0 errors`, `539 warnings`)
+- `pnpm lint`: passing with warnings only (`0 errors`, `501 warnings`)
 
 Top conclusions:
 - A critical Web UI security issue exists in markdown rendering (unsanitized HTML insertion).
@@ -126,7 +126,7 @@ Remediation update (2026-02-16):
 - Severity: Medium
 - Impact: CI noise, reduced confidence in static analysis, and slower defect detection.
 - Evidence:
-  - `pnpm -s lint` => `0 errors`, `539 warnings`
+  - `pnpm -s lint` => `0 errors`, `501 warnings`
   - Error concentration:
     - `src/daemon/models.ts` (90 errors)
     - `src/cli/tui.ts` (25 errors)
@@ -145,7 +145,7 @@ Remediation update (2026-02-16):
 
 Remediation update (2026-02-16):
 - Stage 1 complete: fixed all error-level ESLint violations in impacted high-error files so `pnpm lint` now passes with `0` errors.
-- Stage 2 pending: warning-burn-down remains (currently `539` warnings).
+- Stage 2 in progress: warning-burn-down reduced to `501` warnings via targeted low-risk test cleanup (non-null assertion removal).
 
 ### F-005 Medium: ESLint browser globals mismatch causes avoidable UI lint failures
 
@@ -449,7 +449,7 @@ pnpm -s lint
 
 Observed outcomes:
 - Typecheck/build/test: passing.
-- Lint: passing with warnings only (`0` errors, `539` warnings).
+- Lint: passing with warnings only (`0` errors, `501` warnings).
 
 Historical pre-remediation lint error concentration snapshot:
 - `src/daemon/models.ts`: 90 errors

docs/plans/state.json

@@ -2647,6 +2647,20 @@
         "docs/plans/analysis/2026-02-16-codebase-audit-report.md"
       ],
       "test_status": "pnpm test:run src/gateway/server.test.ts src/tools/executor.test.ts src/backends/native/orchestrator.test.ts src/daemon/routing.test.ts + pnpm typecheck + pnpm lint passing (0 errors, warnings remain)"
+    },
+    "audit-followup-lint-warning-reduction-pass-1": {
+      "status": "in_progress",
+      "date": "2026-02-16",
+      "updated": "2026-02-16",
+      "summary": "Started stage-2 lint warning reduction with low-risk test cleanup: removed non-null assertions and added explicit guards/helpers in selected tests, reducing warning count from 539 to 501 while keeping lint/typecheck/tests green.",
+      "files_modified": [
+        "src/tools/builtin/browser/tools.test.ts",
+        "src/channels/telegram/adapter.test.ts",
+        "src/tools/builtin/system-info.test.ts",
+        "src/mcp/manager.test.ts",
+        "docs/plans/analysis/2026-02-16-codebase-audit-report.md"
+      ],
+      "test_status": "pnpm test:run src/tools/builtin/browser/tools.test.ts src/channels/telegram/adapter.test.ts src/tools/builtin/system-info.test.ts src/mcp/manager.test.ts + pnpm typecheck + pnpm lint passing (0 errors, 501 warnings)"
     }
   },
   "overall_progress": {

src/channels/telegram/adapter.test.ts

@@ -31,6 +31,22 @@ const baseConfig: TelegramAdapterConfig = {
 describe('TelegramAdapter', () => {
   let adapter: TelegramAdapter;
 
+  function getOnHandler(event: string) {
+    const call = mockOn.mock.calls.find((entry) => entry[0] === event);
+    if (!call) {
+      throw new Error(`Missing on-handler for event: ${event}`);
+    }
+    return call[1] as (ctx: unknown) => Promise<void>;
+  }
+
+  function getCommandHandler(command: string) {
+    const call = mockCommand.mock.calls.find((entry) => entry[0] === command);
+    if (!call) {
+      throw new Error(`Missing command handler: ${command}`);
+    }
+    return call[1] as (ctx: unknown) => Promise<void>;
+  }
+
   beforeEach(() => {
     vi.clearAllMocks();
     adapter = new TelegramAdapter(baseConfig);
@@ -153,7 +169,7 @@ describe('TelegramAdapter', () => {
     );
     expect(textHandlerCall).toBeDefined();
 
-    const textHandler = textHandlerCall![1];
+    const textHandler = getOnHandler('message:text');
 
     // Simulate a grammy context object
     const ctx = {
@@ -179,11 +195,7 @@ describe('TelegramAdapter', () => {
   it('text handler does nothing when no message handler is registered', async () => {
     // Don't call onMessage — no handler
     await adapter.connect();
-
+    const textHandler = getOnHandler('message:text');
-    const textHandlerCall = mockOn.mock.calls.find(
-      (call) => call[0] === 'message:text',
-    );
-    const textHandler = textHandlerCall![1];
 
     const ctx = {
       message: { message_id: 1, text: 'test' },
@@ -209,7 +221,7 @@ describe('TelegramAdapter', () => {
     const resetCall = mockCommand.mock.calls.find((call) => call[0] === 'reset');
     expect(resetCall).toBeDefined();
 
-    const resetHandler = resetCall![1];
+    const resetHandler = getCommandHandler('reset');
 
     const ctx = {
       message: { message_id: 99 },
@@ -237,7 +249,7 @@ describe('TelegramAdapter', () => {
     // Find the /model command handler
     const modelCall = mockCommand.mock.calls.find((call) => call[0] === 'model');
     expect(modelCall).toBeDefined();
-    const modelHandler = modelCall![1];
+    const modelHandler = getCommandHandler('model');
 
     const ctx = {
       message: { message_id: 123, text: '/model@flynn_bot default github/gpt-5-mini' },
@@ -298,10 +310,7 @@ describe('TelegramAdapter', () => {
     const startCall = mockStart.mock.calls[0][0];
     startCall.onStart({ id: 12345, username: 'flynn_bot' });
 
-    const textHandlerCall = mockOn.mock.calls.find(
+    const textHandler = getOnHandler('message:text');
-      (call) => call[0] === 'message:text',
-    );
-    const textHandler = textHandlerCall![1];
 
     const ctx = {
       message: { message_id: 42, text: 'Hello everyone', reply_to_message: undefined },
@@ -326,10 +335,7 @@ describe('TelegramAdapter', () => {
     const startCall = mockStart.mock.calls[0][0];
     startCall.onStart({ id: 12345, username: 'flynn_bot' });
 
-    const textHandlerCall = mockOn.mock.calls.find(
+    const textHandler = getOnHandler('message:text');
-      (call) => call[0] === 'message:text',
-    );
-    const textHandler = textHandlerCall![1];
 
     const ctx = {
       message: { message_id: 42, text: '@flynn_bot What is the weather?', reply_to_message: undefined },
@@ -355,10 +361,7 @@ describe('TelegramAdapter', () => {
     const startCall = mockStart.mock.calls[0][0];
     startCall.onStart({ id: 12345, username: 'flynn_bot' });
 
-    const textHandlerCall = mockOn.mock.calls.find(
+    const textHandler = getOnHandler('message:text');
-      (call) => call[0] === 'message:text',
-    );
-    const textHandler = textHandlerCall![1];
 
     const ctx = {
       message: {
@@ -392,10 +395,7 @@ describe('TelegramAdapter', () => {
     const startCall = mockStart.mock.calls[0][0];
     startCall.onStart({ id: 12345, username: 'flynn_bot' });
 
-    const textHandlerCall = mockOn.mock.calls.find(
+    const textHandler = getOnHandler('message:text');
-      (call) => call[0] === 'message:text',
-    );
-    const textHandler = textHandlerCall![1];
 
     const ctx = {
       message: { message_id: 42, text: 'Hello everyone', reply_to_message: undefined },
@@ -421,10 +421,7 @@ describe('TelegramAdapter', () => {
     const startCall = mockStart.mock.calls[0][0];
     startCall.onStart({ id: 12345, username: 'flynn_bot' });
 
-    const textHandlerCall = mockOn.mock.calls.find(
+    const textHandler = getOnHandler('message:text');
-      (call) => call[0] === 'message:text',
-    );
-    const textHandler = textHandlerCall![1];
 
     const ctx = {
       message: { message_id: 42, text: 'Hello Flynn', reply_to_message: undefined },
@@ -450,10 +447,7 @@ describe('TelegramAdapter', () => {
     const startCall = mockStart.mock.calls[0][0];
     startCall.onStart({ id: 12345, username: 'flynn_bot' });
 
-    const textHandlerCall = mockOn.mock.calls.find(
+    const textHandler = getOnHandler('message:text');
-      (call) => call[0] === 'message:text',
-    );
-    const textHandler = textHandlerCall![1];
 
     const ctx = {
       message: { message_id: 42, text: '@flynn_bot tell me a joke', reply_to_message: undefined },

src/mcp/manager.test.ts

@@ -32,6 +32,13 @@ describe('McpManager', () => {
   let registry: ToolRegistry;
   let manager: McpManager;
 
+  function assertDefined<T>(value: T | undefined): T {
+    if (value === undefined) {
+      throw new Error('Expected value to be defined');
+    }
+    return value;
+  }
+
   beforeEach(() => {
     vi.clearAllMocks();
     registry = new ToolRegistry();
@@ -48,8 +55,8 @@ describe('McpManager', () => {
     // Tool should be registered with mcp: prefix
     const tool = registry.get('mcp:test-server:do_thing');
     expect(tool).toBeDefined();
-    expect(tool!.name).toBe('mcp:test-server:do_thing');
+    expect(assertDefined(tool).name).toBe('mcp:test-server:do_thing');
-    expect(tool!.description).toContain('[MCP:test-server]');
+    expect(assertDefined(tool).description).toContain('[MCP:test-server]');
   });
 
   it('startAll handles multiple servers', async () => {
@@ -135,9 +142,9 @@ describe('McpManager', () => {
 
     const state = manager.getServerState('test-server');
     expect(state).toBeDefined();
-    expect(state!.config.name).toBe('test-server');
+    expect(assertDefined(state).config.name).toBe('test-server');
-    expect(state!.config.args).toEqual(['--flag']);
+    expect(assertDefined(state).config.args).toEqual(['--flag']);
-    expect(state!.tools).toHaveLength(1);
+    expect(assertDefined(state).tools).toHaveLength(1);
   });
 
   it('getRegisteredTools returns all MCP tools', async () => {
@@ -163,7 +170,7 @@ describe('McpManager', () => {
 
     const state = manager.getServerState('test-server');
     expect(state).toBeDefined();
-    expect(state!.config.args).toEqual(['--arg1']);
+    expect(assertDefined(state).config.args).toEqual(['--arg1']);
     expect(registry.get('mcp:test-server:do_thing')).toBeDefined();
   });
 

src/tools/builtin/browser/tools.test.ts

@@ -34,6 +34,14 @@ const mockManager = {
 describe('Browser tools', () => {
   let tools: ReturnType<typeof createBrowserTools>;
 
+  function getTool(name: string) {
+    const tool = tools.find(t => t.name === name);
+    if (!tool) {
+      throw new Error(`Tool not found: ${name}`);
+    }
+    return tool;
+  }
+
   beforeEach(() => {
     vi.clearAllMocks();
     tools = createBrowserTools(mockManager);
@@ -51,7 +59,7 @@ describe('Browser tools', () => {
   });
 
   it('browser.navigate navigates to URL', async () => {
-    const tool = tools.find(t => t.name === 'browser.navigate')!;
+    const tool = getTool('browser.navigate');
     const result = await tool.execute({ url: 'https://example.com' });
     expect(result.success).toBe(true);
     expect(result.output).toContain('example.com');
@@ -59,13 +67,13 @@ describe('Browser tools', () => {
   });
 
   it('browser.navigate respects custom waitUntil', async () => {
-    const tool = tools.find(t => t.name === 'browser.navigate')!;
+    const tool = getTool('browser.navigate');
     await tool.execute({ url: 'https://example.com', waitUntil: 'networkidle0' });
     expect(mockGoto).toHaveBeenCalledWith('https://example.com', { waitUntil: 'networkidle0' });
   });
 
   it('browser.screenshot takes page screenshot', async () => {
-    const tool = tools.find(t => t.name === 'browser.screenshot')!;
+    const tool = getTool('browser.screenshot');
     const result = await tool.execute({});
     expect(result.success).toBe(true);
     expect(result.output).toContain('Screenshot captured');
@@ -73,7 +81,7 @@ describe('Browser tools', () => {
   });
 
   it('browser.screenshot takes element screenshot', async () => {
-    const tool = tools.find(t => t.name === 'browser.screenshot')!;
+    const tool = getTool('browser.screenshot');
     const result = await tool.execute({ selector: '#header' });
     expect(result.success).toBe(true);
     expect(mock$).toHaveBeenCalledWith('#header');
@@ -81,28 +89,28 @@ describe('Browser tools', () => {
 
   it('browser.screenshot fails for missing element', async () => {
     mock$.mockResolvedValueOnce(null);
-    const tool = tools.find(t => t.name === 'browser.screenshot')!;
+    const tool = getTool('browser.screenshot');
     const result = await tool.execute({ selector: '#nonexistent' });
     expect(result.success).toBe(false);
     expect(result.error).toContain('Element not found');
   });
 
   it('browser.click clicks element', async () => {
-    const tool = tools.find(t => t.name === 'browser.click')!;
+    const tool = getTool('browser.click');
     const result = await tool.execute({ selector: '#submit' });
     expect(result.success).toBe(true);
     expect(mockClick).toHaveBeenCalledWith('#submit');
   });
 
   it('browser.type types into element', async () => {
-    const tool = tools.find(t => t.name === 'browser.type')!;
+    const tool = getTool('browser.type');
     const result = await tool.execute({ selector: '#search', text: 'hello' });
     expect(result.success).toBe(true);
     expect(mockType).toHaveBeenCalledWith('#search', 'hello');
   });
 
   it('browser.type clears field before typing when clear=true', async () => {
-    const tool = tools.find(t => t.name === 'browser.type')!;
+    const tool = getTool('browser.type');
     await tool.execute({ selector: '#search', text: 'hello', clear: true });
     expect(mockClick).toHaveBeenCalledWith('#search', { count: 3 });
     expect(mockKeyboard.press).toHaveBeenCalledWith('Backspace');
@@ -110,7 +118,7 @@ describe('Browser tools', () => {
   });
 
   it('browser.content returns page text', async () => {
-    const tool = tools.find(t => t.name === 'browser.content')!;
+    const tool = getTool('browser.content');
     const result = await tool.execute({});
     expect(result.success).toBe(true);
     expect(result.output).toContain('Page content here');
@@ -119,13 +127,13 @@ describe('Browser tools', () => {
   });
 
   it('browser.content uses custom selector', async () => {
-    const tool = tools.find(t => t.name === 'browser.content')!;
+    const tool = getTool('browser.content');
     await tool.execute({ selector: '#main' });
     expect(mock$eval).toHaveBeenCalledWith('#main', expect.any(Function));
   });
 
   it('browser.eval evaluates JS', async () => {
-    const tool = tools.find(t => t.name === 'browser.eval')!;
+    const tool = getTool('browser.eval');
     const result = await tool.execute({ expression: '1 + 1' });
     expect(result.success).toBe(true);
     expect(result.output).toContain('42');
@@ -133,7 +141,7 @@ describe('Browser tools', () => {
 
   it('browser.eval returns string results directly', async () => {
     mockEvaluate.mockResolvedValueOnce('hello world');
-    const tool = tools.find(t => t.name === 'browser.eval')!;
+    const tool = getTool('browser.eval');
     const result = await tool.execute({ expression: '"hello world"' });
     expect(result.success).toBe(true);
     expect(result.output).toBe('hello world');
@@ -141,7 +149,7 @@ describe('Browser tools', () => {
 
   it('handles navigation errors gracefully', async () => {
     mockGoto.mockRejectedValueOnce(new Error('Navigation failed'));
-    const tool = tools.find(t => t.name === 'browser.navigate')!;
+    const tool = getTool('browser.navigate');
     const result = await tool.execute({ url: 'https://broken.example.com' });
     expect(result.success).toBe(false);
     expect(result.error).toContain('Navigation failed');
@@ -149,14 +157,14 @@ describe('Browser tools', () => {
 
   it('handles click errors gracefully', async () => {
     mockClick.mockRejectedValueOnce(new Error('Element not found'));
-    const tool = tools.find(t => t.name === 'browser.click')!;
+    const tool = getTool('browser.click');
     const result = await tool.execute({ selector: '#missing' });
     expect(result.success).toBe(false);
     expect(result.error).toContain('Element not found');
   });
 
   it('returns aborted error when signal is already aborted', async () => {
-    const tool = tools.find(t => t.name === 'browser.navigate')!;
+    const tool = getTool('browser.navigate');
     const controller = new AbortController();
     controller.abort();
 

src/tools/builtin/system-info.test.ts

@@ -1,6 +1,13 @@
 import { describe, it, expect } from 'vitest';
 import { systemInfoTool } from './system-info.js';
 
+function getOutput(output: string | undefined): string {
+  if (!output) {
+    throw new Error('Expected output');
+  }
+  return output;
+}
+
 describe('system.info tool', () => {
   // ── Metadata ─────────────────────────────────────────────────────────────
 
@@ -17,14 +24,14 @@ describe('system.info tool', () => {
 
     expect(result.success).toBe(true);
     expect(typeof result.output).toBe('string');
-    expect(result.output!.length).toBeGreaterThan(0);
+    expect(getOutput(result.output).length).toBeGreaterThan(0);
   });
 
   it('output contains expected fields', async () => {
     const result = await systemInfoTool.execute({});
 
     expect(result.success).toBe(true);
-    const output = result.output!;
+    const output = getOutput(result.output);
 
     const expectedFields = [
       'Date:',
@@ -46,17 +53,17 @@ describe('system.info tool', () => {
     const result = await systemInfoTool.execute({});
 
     expect(result.success).toBe(true);
-    const output = result.output!;
+    const output = getOutput(result.output);
 
     // Find the line containing 'ISO 8601:'
     const isoLine = output.split('\n').find((line) => line.includes('ISO 8601:'));
     expect(isoLine).toBeTruthy();
 
     // Extract the ISO string and validate it
-    const isoMatch = isoLine!.match(/ISO 8601:\s*(.+)/);
+    const isoMatch = getOutput(isoLine).match(/ISO 8601:\s*(.+)/);
     expect(isoMatch).toBeTruthy();
 
-    const isoString = isoMatch![1].trim();
+    const isoString = getOutput(isoMatch?.[1]).trim();
     const parsed = new Date(isoString);
     expect(parsed.toISOString()).toBe(isoString);
   });
@@ -78,7 +85,7 @@ describe('system.info tool', () => {
     expect(result2.success).toBe(true);
     expect(typeof result1.output).toBe('string');
     expect(typeof result2.output).toBe('string');
-    expect(result1.output!.length).toBeGreaterThan(0);
+    expect(getOutput(result1.output).length).toBeGreaterThan(0);
-    expect(result2.output!.length).toBeGreaterThan(0);
+    expect(getOutput(result2.output).length).toBeGreaterThan(0);
   });
 });