test(codex): add unit coverage for JSONL event parser helpers

[aaight]

Summary

• Adds a new tests/unit/backends/codex-jsonlParser.test.ts with 56 tests covering all pure helper functions in src/backends/codex/jsonlParser.ts
• Extends tests/unit/backends/codex.test.ts with 8 additional extractToolCall Responses API cases including malformed argument payloads
• All 125 tests pass; lint and typecheck clean

What was tested

New codex-jsonlParser.test.ts covers:

• extractTextFromContentParts — array/non-array input, string items, type-filtered objects, mixed arrays, whitespace-only text, no-type objects
• extractItemText — agent_message, message/content, command_execution, function_call, null/non-object inputs
• extractDeltaText — plain string delta, text_delta objects, empty/whitespace, null, non-text delta objects, arrays
• parseFunctionCallItem — string arguments, malformed JSON arguments, object arguments, command_execution items, no-command guard, empty name guard, complex nested arguments
• resolveUsageRecord — flat event.usage, event.token_usage, nested response.usage (Responses API), priority ordering, missing usage, non-object response.usage
• parseCodexEvent — full integration: text events, tool_use, turn.completed, response.completed, agent_message, function_call with malformed args, command_execution, item.delta, error events, unrecognized events, mixed content arrays, cost_usd, camelCase usage fields

Extended codex.test.ts extractToolCall cases:

• item.completed with non-function_call item type returns null
• Malformed JSON arguments in item.completed function_call
• item.completed function_call with object (non-string) arguments
• item.completed with no item field returns null
• item.completed with null item returns null
• tool_name without tool_input (input is undefined)

Trello card

https://trello.com/c/69c3e0f9853cbbb3920a0e0f

🕵️ claude-code · claude-sonnet-4-6 · run details

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[nhopeatall]

LGTM — Thorough unit test coverage for all exported helpers in jsonlParser.ts. Tests accurately reflect the source implementation (traced every expectation against the source), edge cases are well-chosen (malformed JSON, null/undefined inputs, whitespace-only strings, priority ordering in resolveUsageRecord), and the new extractToolCall cases in codex.test.ts fill real gaps (malformed args, null items, object arguments). All CI checks pass.

🕵️ claude-code · claude-opus-4-6 · run details