[BUG] argparse -f conflict: --diff-base PR introduced global --format/-f that clashes with subparser --format/-f

[Wolfvin]

Problem

Any codelens CLI invocation crashes with:

argparse.ArgumentError: argument --format/-f: conflicting option string(s): -f

Root cause: PR #157 (--diff-base flag) added --format/-f at the global parser level (line ~926 in scripts/codelens.py). But subparsers already define --format/-f at the subparser level. argparse does not allow duplicate short flags across parent and child parsers.

Reported independently by workers fixing PR #139 (formatters) and PR #141 (baseline diff).

Impact

• codelens --help crashes
• codelens scan . crashes
• Any command with -f flag crashes
• Breaks test_cli.py and test_doctor.py smoke tests
• PR feat(ci): baseline diff + strict mode + diff-scan flags (closes #57 phase 1+2) #141's worker worked around it by restoring an existing_option_strings guard — but the underlying root cause remains on main

Fix

Two options:

Option A (recommended): Remove the -f short alias from the global --format flag added in PR #157. Keep --format (long form only) at global level. Subparsers keep their --format/-f. This is non-breaking — users who use codelens -f json can use codelens --format json instead.

Option B: Remove the global --format flag entirely from PR #157's addition. The --diff-base flag doesn't need format at global level — format is already available per-subcommand.

Definition of Done

• codelens --help runs without error
• codelens scan . --format json runs without argparse error
• codelens scan . -f json works
• test_cli.py and test_doctor.py pass
• No regression on --diff-base functionality (PR [FEAT] --diff-base flag: scope all analysis commands to changed files only #157 feature still works)

[Wolfvin]

🔄 Taking this issue

Mengerjakan issue ini -- 2026-07-03T03:32:40Z

[Wolfvin]

PR siap review

PR: #175 — fix(cli): add regression tests for argparse -f conflict (closes #174)
Branch: fix/issue-174-argparse-f-conflict
Summary: Issue #174 reported a P0 argparse -f conflict crash. The bug was already fixed on main by commit 23487af (fix #171, which restored the existing_option_strings guard dropped by PR #153). Issue #174 was created 14 seconds before the fix merged — a race condition. This PR adds 7 regression tests + a defensive comment to prevent the bug from returning. Also fixes pre-existing command count drift (76→77 in docs).
Tests: 142 passed, 0 skipped, 0 failed (test_cli + test_doctor + test_command_count + test_command_registry + test_formatters)