fix: use max_completion_tokens for reasoning models (o1/o3/o4/gpt-5)

[majiayu000]

Fixes #529

Problem

Newer OpenAI models (o1, o3, o4, gpt-5 series) reject the max_tokens parameter and require max_completion_tokens instead. These reasoning models also don't support temperature and top_p parameters.

Changes

In src/engine/openAi.ts, added model detection (/^(o[1-9]|gpt-5)/) to conditionally:

• Use max_completion_tokens instead of max_tokens for reasoning models
• Omit temperature and top_p for reasoning models (they don't support these)
• Keep existing behavior for all other models

The detection pattern is consistent with the existing pattern in src/utils/modelCache.ts.

[di-sukharev]

@majiayu000 thank you for the contribution, please fix the tests and i merge it🙏

[majiayu000]

fixed — two issues: chalk was missing from jest transformIgnorePatterns (ESM import error), and gemini.test.ts had a wrong mock path (../src -> ../../src). all 4 unit test suites pass now

[di-sukharev]

@majiayu000 one test is still failing at https://github.com/di-sukharev/opencommit/actions/runs/23655960709/job/69058677428?pr=544

FAIL test/unit/gemini.test.ts (15.153 s)
  ● Gemini › should generate commit message

    Cannot find module '../../src/commands/config' from 'test/jest-setup.ts'

      34 |
      35 |     jest.mock('@google/generative-ai');
    > 36 |     jest.mock('../../src/commands/config');
         |          ^
      37 |
      38 |     jest.mock('@clack/prompts', () => ({
      39 |       intro: jest.fn(),

      at Resolver._throwModNotFoundError (node_modules/jest-resolve/build/resolver.js:427:11)
      at Object.<anonymous> (test/unit/gemini.test.ts:36:10)


  ● Test suite failed to run

    TypeError: Cannot read properties of undefined (reading 'mockRestore')

      60 |
      61 |   afterAll(() => {
    > 62 |     mockExit.mockRestore();
         |              ^
      63 |     process.env = oldEnv;
      64 |   });
      65 |

      at Object.<anonymous> (test/unit/gemini.test.ts:62:14)

PASS test/unit/config.test.ts (15.17 s)

[di-sukharev]

you can solve this conflict however is easier for you, we anyway regenerate the /out folder on every npm version submission, so feel free to ignore it or resolve like you want, it doesnt matter really

[majiayu000]

@di-sukharev Rebased on master and fixed all CI failures:

1. gemini.test.ts — reverted the mock path back to ../src/commands/config (Jest resolves it relative to test/jest-setup.ts, not the test file itself)
2. prettier — fixed indentation in openAi.ts
3. /out conflict — removed the conflicting out/ files since they'll be regenerated on release

All three should be green now 🙏

[di-sukharev]

thank you @majiayu000