claude-print/notes/bf-2pw.md

bf-2pw: Emitter Implementation Verification

Status: COMPLETE

Implementation was completed in commit bfb50da on 2024-06-10.

Implementation Summary

src/emitter.rs provides three output format handlers:

Text Format (OutputFormat::Text)

• Writes response text to stdout with trailing newline
• Error messages go to stderr only

JSON Format (OutputFormat::Json)

• Single-line JSON result object to stdout
• Fields included:
  • type: "result"
  • subtype: "success" or error subtype
  • is_error: boolean
  • result: response text (success) or omitted (error)
  • session_id: optional session identifier
  • num_turns: turn count
  • duration_ms: session duration
  • cost_usd: cost (currently 0)
  • claude_version: Claude Code version
  • usage: token counts (input, output, cache_creation, cache_read)

Stream-JSON Format (OutputFormat::StreamJson)

• Reader thread spawned via spawn_stream_json_reader()
• Forwards JSONL transcript lines to stdout in real-time
• Supports graceful shutdown via drain_tx channel
• Handles missing file with retry loop

Error Reporting

• emit_error() handles both JSON and text modes
• JSON mode writes to stdout, text mode to stderr
• Exit codes: Setup(2), Timeout(124), Interrupted(130), AssistantError(1)

Test Coverage

All 13 tests pass:

• Text format: trailing newline, no extra whitespace
• JSON format: all required fields present, integers for usage
• Error handling: correct is_error, subtype, exit codes
• Stream-json: line parsing, disconnect handling

Verification Results

test test_error_exit_code_nonzero ... ok
test test_error_exit_codes ... ok
test test_error_subtypes ... ok
test test_error_result_is_error_true_and_subtype ... ok
test test_json_claude_version_included ... ok
test test_json_usage_fields_are_integers ... ok
test test_json_valid_with_required_fields ... ok
test test_stream_json_disconnect_exits_immediately ... ok
test test_text_correct_string_trailing_newline ... ok
test test_stream_json_each_line_parses_as_json ... ok
test test_text_error_goes_to_stderr_not_stdout ... ok
test test_text_no_extra_whitespace ... ok
test test_zero_token_counts_when_fallback ... ok

test result: ok. 13 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

Verified 2024-06-11.