Share GitHub Project transport-error classification

[codeforester]

Goal

Create one shared transport-error predicate or marker set with an explicit GraphQL-only extension. Retain transport-specific authentication classification and duplicate-item handling.

Background

Repository-wide duplication review against f9c18f3294873cbbcda9acc7af7f1bc6b17eed45 (2026-09-17).

GraphQL and REST each maintain their own transport-error marker tuple and nearly identical lowercase/any logic (97% token similarity). All REST transport markers appear in the GraphQL copy; GraphQL additionally handles unknown owner type. Live pure-function probes confirmed the common classifications and that deliberate difference. These decisions control fallback and fail-closed behavior.

Verified source locations:

• cli/python/base_github_projects/project_graphql.py:48-77
• cli/python/base_github_projects/project_rest.py:102-138

Closed #2230 added local REST recovery. No open issue covers the duplicate transport predicates introduced by the two adapters.

This is a maintainability refactor. Similarity alone is not evidence of a production failure; any demonstrated differences are called out above.

Scope

Create one shared transport-error predicate or marker set with an explicit GraphQL-only extension. Retain transport-specific authentication classification and duplicate-item handling.

Acceptance Criteria

• Common network/rate-limit/server markers are maintained once.
• Preserve the GraphQL-only unknown owner type recovery trigger.
• Authentication and permission failures do not become generic retryable transport failures.
• Preserve current exception classes, fallback routing and request timeout behavior.

Validation

Run project_graphql/project_rest tests; parameterize every current marker plus benign text, auth failures and GraphQL-only owner errors through both callers.

Run focused checks first, then the repository-required broader checks for the actual implementation. Preserve public command contracts and review .ai-context/ impact in the PR.

Non-Goals

No merger of REST and GraphQL response parsing; no new retries, quota bypasses or network behavior.

Project Fields

• Status: Ready
• Priority: P2
• Area: CLI
• Initiative: Contract Hardening
• Size: S
• Milestone: Unscheduled; no release commitment is implied by this audit.

Agent Assignment

Implementation-ready scoped follow-up, assigned to codeforester. Follow AGENTS.md and docs/github-workflow.md: start through basectl gh issue start, use the canonical issue worktree, characterize current behavior before extraction, and open an issue-linked PR. Keep each refactor independently reviewable.

[codeforester]

Validated this against commit f9c18f3 (the reviewed commit). The core finding holds — is_project_transport_error in project_graphql.py and project_rest.py really is ~97% token-similar, GraphQL really is a strict superset (adds unknown owner type), and no open issue currently covers this.

One precision note on the citations: the two "verified source locations" ranges are wider than the actual duplicated code. project_graphql.py:48-77 and project_rest.py:102-138 each also include an adjacent, structurally unrelated function — is_project_scope_error (48-53) in the GraphQL file and is_project_auth_error (102-114) in the REST file — neither of which resembles the other or is part of the transport-error duplication being described. The actual ~97%-similar pair is just is_project_transport_error (graphql.py:56-77, rest.py:117-138). Narrowing the citation to that range would keep the evidence exactly matched to the claim; as written, a reviewer opening the full cited range would see extra, unrelated code mixed in. Doesn't change the validity of the fix itself.