DM-54689: Extract _require_github_app_config() helper in Factory to dedupe three-way None check

[jonathansick]

Metadata

Field	Value
Parent PRD	#232
Jira Key	DM-54689
Jira URL	https://rubinobs.atlassian.net/browse/DM-54689
Task Order	22
Type	AFK
Blocked by	None
Parallel with	#266, #268, #269
Branch	tickets/DM-54689-github-webhook

Origin

Review of PR #264

What to build

src/docverse/factory.py repeats the same three-way is None check on _github_app_id, _github_app_private_key, and _github_webhook_secret in two methods:

• create_github_app_client (lines ~300-306).
• get_github_webhook_secret (lines ~420-441).

Both raise GitHubAppNotConfiguredError with the same message. Extract a private helper so the two sites cannot drift.

Approach sketch

Add _require_github_app_config(self) -> tuple[int, SecretStr, SecretStr] (or a small named tuple / dataclass) that performs the all-or-nothing check and returns the three values typed as non-None. Both call sites delegate. Helper raises GitHubAppNotConfiguredError with the existing message.

Acceptance criteria

• One private helper performs the three-way None check and returns the resolved values.
• create_github_app_client and get_github_webhook_secret call the helper.
• No duplicated if ... is None or ... is None or ... is None blocks remain in factory.py.
• Existing factory and webhook tests pass unchanged.
• uv run --only-group=nox nox -s typing clean.

[jonathansick]

✓ Implemented in commit f1b3e8c — PR #264