fix(cli): catch corrupted credentials file at import time

[deanq]

Related to runpod/runpod-python#481

Summary

• New thin CLI entrypoint (entrypoint.py) wraps the import of runpod_flash.cli.main in a try/except to catch TOMLDecodeError from the runpod package's import-time credential read.
• Surfaces a clean error message suggesting flash login instead of a raw traceback.
• Console script updated in pyproject.toml: flash = "runpod_flash.cli.entrypoint:main"

Root cause: runpod/__init__.py calls get_credentials() -> toml.load() at import time. Flash's existing handler in credentials.py never runs because the crash happens during import runpod. This is defense-in-depth alongside the root cause fix in runpod-python.

Fixes: AE-2576
Depends on: runpod/runpod-python#478 (root cause fix)
Related: AE-2485 (fixed Flash's own read path)

Test plan

• test_normal_import_runs_app -- happy path invokes Typer app
• test_corrupted_toml_shows_clean_error -- TOMLDecodeError gives clean stderr + exit 1
• test_non_toml_value_error_propagates -- unrelated ValueError still raises
• All 2538 existing tests pass, 85.83% coverage

[Copilot]

Pull request overview

Adds a defensive CLI entrypoint wrapper so flash can fail gracefully when runpod crashes at import-time due to a corrupted ~/.runpod/config.toml, instead of showing a raw traceback.

Changes:

• Introduce runpod_flash.cli.entrypoint:main to wrap importing the Typer app and catch TOML decode failures.
• Update the console script target from runpod_flash.cli.main:app to the new wrapper entrypoint.
• Add unit tests covering the happy path, TOML decode handling, and non-TOML ValueError propagation.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/runpod_flash/cli/entrypoint.py	New thin entrypoint that catches import-time TOML decode errors and prints a clean remediation message.
pyproject.toml	Points flash console script to the new entrypoint wrapper.
tests/unit/cli/test_entrypoint.py	New tests validating wrapper behavior for success, TOML decode, and unrelated errors.

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[runpod-Henrik]

1. Approach — correct, live-verified

The root cause (runpod/__init__.py calling toml.load() at import time before any Flash error handling can run) requires a wrapper outside the normal import chain. The thin entrypoint that catches during from runpod_flash.cli.main import app is the right level to intercept this. The PR description correctly frames this as defense-in-depth alongside the runpod-python root cause fix.

Live-verified on PR branch: corrupted config.toml produces a clean error and exits 1. Normal operation unaffected.

2. Bug: parse error location dropped — user can't identify or fix the corruption

Error: ~/.runpod/config.toml is corrupted and cannot be parsed.
Run 'flash login' to re-authenticate, or delete the file and retry.

The TOMLDecodeError includes the parse location (e.g. "Expected '=' after a key in a key/value pair (at line 1, column 6)"). The current message drops it. A user whose config is partially corrupted (e.g. a single bad line after a manual edit) can't identify or repair the file — they're told to delete it or re-authenticate regardless. Including str(exc) would help:

print(
    f"Error: ~/.runpod/config.toml is corrupted and cannot be parsed: {exc}\n"
    "Run 'flash login' to re-authenticate, or delete the file and retry.",
    file=sys.stderr,
)

3. Question: detection logic — implicit tomllib coverage

The check is:

exc_module.startswith("toml")
or exc_module.startswith("tomli")
or exc_module.startswith("tomllib")

"tomllib".startswith("toml") and "tomli".startswith("toml") are both True, so the last two branches are unreachable — startswith("toml") covers all three. Either collapse to one check, or keep all three explicitly with a comment.

Nits

• raise SystemExit(1) from None suppresses the exception chain entirely. If a user runs flash with --debug or in a context where tracebacks are useful, the chain is gone. Acceptable for a user-facing CLI, but worth noting.
• No test for ImportError (missing runpod package) — correctly propagates uncaught, but a comment in the source noting which error classes are intentionally not caught would help future readers.

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Verdict: PASS WITH NITS

The fix works. Item 2 is the main nit worth addressing before merge — the parse location in the error message is the difference between "delete everything and re-login" and "fix line 3 of your config file".

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