fix(thinking): handle clear no-op and tighten override coverage

tests/unit/cliproxy/codex-reasoning-proxy-extended-context.test.ts

@@ -5,6 +5,11 @@ import {
   CodexReasoningProxy,
   getEffortForModel,
 } from '../../../src/cliproxy/codex-reasoning-proxy';
+import {
+  parseEnvThinkingOverride,
+  resolveRuntimeThinkingOverride,
+  shouldDisableCodexReasoning,
+} from '../../../src/cliproxy/executor/thinking-override-resolver';
 
 type JsonRecord = Record<string, unknown>;
 
@@ -224,4 +229,122 @@ describe('CodexReasoningProxy extended-context compatibility', () => {
     expect(response.statusCode).toBe(200);
     expect(capturedBody?.model).toBe('enterprise-internal-high');
   });
+
+  it('keeps reasoning enabled when CCS_THINKING=high overrides config off', async () => {
+    let capturedBody: JsonRecord | null = null;
+
+    expect(parseEnvThinkingOverride('high')).toBe('high');
+    const { thinkingOverride } = resolveRuntimeThinkingOverride(undefined, 'high');
+    const disableEffort = shouldDisableCodexReasoning(
+      {
+        mode: 'off',
+        tier_defaults: {
+          opus: 'high',
+          sonnet: 'medium',
+          haiku: 'low',
+        },
+        show_warnings: true,
+      },
+      thinkingOverride
+    );
+
+    const upstream = http.createServer((req, res) => {
+      let rawBody = '';
+      req.setEncoding('utf8');
+      req.on('data', (chunk) => {
+        rawBody += chunk;
+      });
+      req.on('end', () => {
+        capturedBody = rawBody ? (JSON.parse(rawBody) as JsonRecord) : {};
+        res.writeHead(200, { 'Content-Type': 'application/json' });
+        res.end(JSON.stringify({ ok: true }));
+      });
+    });
+    cleanupServers.push(upstream);
+
+    const upstreamPort = await listenOnRandomPort(upstream);
+    const proxy = new CodexReasoningProxy({
+      upstreamBaseUrl: `http://127.0.0.1:${upstreamPort}`,
+      disableEffort,
+      defaultEffort: 'medium',
+      modelMap: {
+        defaultModel: 'gpt-5.3-codex',
+      },
+    });
+
+    const proxyPort = await proxy.start();
+    const response = await postJson(
+      `http://127.0.0.1:${proxyPort}/api/provider/codex/v1/messages`,
+      {
+        model: 'gpt-5.3-codex-high',
+        messages: [],
+      }
+    );
+
+    proxy.stop();
+
+    expect(response.statusCode).toBe(200);
+    expect(disableEffort).toBe(false);
+    expect(capturedBody?.model).toBe('gpt-5.3-codex');
+    expect((capturedBody?.reasoning as JsonRecord | undefined)?.effort).toBe('high');
+  });
+
+  it('disables reasoning when CCS_THINKING=off is provided', async () => {
+    let capturedBody: JsonRecord | null = null;
+
+    expect(parseEnvThinkingOverride('off')).toBe('off');
+    const { thinkingOverride } = resolveRuntimeThinkingOverride(undefined, 'off');
+    const disableEffort = shouldDisableCodexReasoning(
+      {
+        mode: 'auto',
+        tier_defaults: {
+          opus: 'high',
+          sonnet: 'medium',
+          haiku: 'low',
+        },
+        show_warnings: true,
+      },
+      thinkingOverride
+    );
+
+    const upstream = http.createServer((req, res) => {
+      let rawBody = '';
+      req.setEncoding('utf8');
+      req.on('data', (chunk) => {
+        rawBody += chunk;
+      });
+      req.on('end', () => {
+        capturedBody = rawBody ? (JSON.parse(rawBody) as JsonRecord) : {};
+        res.writeHead(200, { 'Content-Type': 'application/json' });
+        res.end(JSON.stringify({ ok: true }));
+      });
+    });
+    cleanupServers.push(upstream);
+
+    const upstreamPort = await listenOnRandomPort(upstream);
+    const proxy = new CodexReasoningProxy({
+      upstreamBaseUrl: `http://127.0.0.1:${upstreamPort}`,
+      disableEffort,
+      defaultEffort: 'medium',
+      modelMap: {
+        defaultModel: 'gpt-5.3-codex',
+      },
+    });
+
+    const proxyPort = await proxy.start();
+    const response = await postJson(
+      `http://127.0.0.1:${proxyPort}/api/provider/codex/v1/messages`,
+      {
+        model: 'gpt-5.3-codex-high',
+        messages: [],
+      }
+    );
+
+    proxy.stop();
+
+    expect(response.statusCode).toBe(200);
+    expect(disableEffort).toBe(true);
+    expect(capturedBody?.model).toBe('gpt-5.3-codex');
+    expect((capturedBody?.reasoning as JsonRecord | undefined)?.effort).toBeUndefined();
+  });
 });

tests/unit/commands/config-thinking-command.test.ts

@@ -3,6 +3,7 @@ import {
   parseThinkingCommandArgs,
   parseThinkingOverrideInput,
 } from '../../../src/commands/config-thinking-command';
+import { clearProviderOverride } from '../../../src/commands/config-thinking-parser';
 
 describe('config thinking command parser', () => {
   it('rejects missing required option values', () => {
@@ -41,3 +42,47 @@ describe('config thinking override normalization', () => {
     expect(parseThinkingOverrideInput('8192')).toEqual({ value: 8192 });
   });
 });
+
+describe('config thinking provider override clearing', () => {
+  it('is a no-op when provider override does not exist', () => {
+    const result = clearProviderOverride(
+      {
+        codex: { opus: 'high' },
+      },
+      'gemini'
+    );
+
+    expect(result.changed).toBe(false);
+    expect(result.nextOverrides).toEqual({
+      codex: { opus: 'high' },
+    });
+  });
+
+  it('is a no-op when provider exists but tier override does not', () => {
+    const result = clearProviderOverride(
+      {
+        codex: { opus: 'high' },
+      },
+      'codex',
+      'haiku'
+    );
+
+    expect(result.changed).toBe(false);
+    expect(result.nextOverrides).toEqual({
+      codex: { opus: 'high' },
+    });
+  });
+
+  it('removes provider entry when last tier is cleared', () => {
+    const result = clearProviderOverride(
+      {
+        codex: { opus: 'high' },
+      },
+      'codex',
+      'opus'
+    );
+
+    expect(result.changed).toBe(true);
+    expect(result.nextOverrides).toBeUndefined();
+  });
+});

tests/unit/web-server/thinking-routes-logic.test.ts

@@ -0,0 +1,42 @@
+import { describe, expect, it } from 'bun:test';
+import { resolveThinkingProviderOverridesForSave } from '../../../src/web-server/routes/misc-routes';
+
+describe('thinking routes logic', () => {
+  it('clears provider overrides when clear flag is set', () => {
+    const result = resolveThinkingProviderOverridesForSave(
+      {
+        codex: { opus: 'high' },
+      },
+      {
+        gemini: { sonnet: 'medium' },
+      },
+      true
+    );
+
+    expect(result).toBeUndefined();
+  });
+
+  it('applies normalized updates when provided and clear flag is false', () => {
+    const updates = {
+      gemini: { sonnet: 'medium' },
+    };
+    const result = resolveThinkingProviderOverridesForSave(
+      {
+        codex: { opus: 'high' },
+      },
+      updates,
+      false
+    );
+
+    expect(result).toEqual(updates);
+  });
+
+  it('preserves current overrides when no updates are provided', () => {
+    const current = {
+      codex: { opus: 'high' },
+    };
+    const result = resolveThinkingProviderOverridesForSave(current, undefined, false);
+
+    expect(result).toEqual(current);
+  });
+});