pdftract/notes/pdftract-5n2lu.md

Verification Note: pdftract-5n2lu (Phase 1.6: Error Recovery)

Status: COMPLETE

Child Beads

• ✅ pdftract-29z7b: Define unified Diagnostic types + diagnostic code catalog (closed)
• ✅ pdftract-4w0v4: Adversarial test corpus + integration assertion harness (closed)

Note: Bead description mentions 3 child beads, but only 2 exist in the dependency graph. The "integer overflow clamping helper" was likely implemented as part of other parser beads.

Acceptance Criteria

All Critical tests pass (plan Section 1.6, lines 1195-1198)

All 8 integration tests in crates/pdftract-core/tests/error_recovery_integration.rs pass:

$ cargo test -p pdftract-core --test error_recovery_integration
running 8 tests
test test_combined_failures ... ok
test test_int_overflow_bbox ... ok
test test_missing_endobj ... ok
test test_inv_8_no_panics_across_all_fixtures ... ok
test test_truncated_mid_stream ... ok
test test_nested_failure ... ok
test test_missing_mediabox_all_pages ... ok
test test_xref_30pct_bad_offsets ... ok

test result: ok. 8 passed; 0 failed; 0 ignored

Critical test coverage:

• ✅ test_xref_30pct_bad_offsets: 70 objects extracted; 30+ STRUCT_INVALID_XREF_ENTRY diagnostics
• ✅ test_missing_mediabox_all_pages: 10 pages, each with 612×792 default + STRUCT_MISSING_KEY
• ✅ test_missing_endobj: object 5 recovered; objects 6+ still parseable
• ✅ test_combined_failures: >= 5 pages extracted; ~10 diagnostics; no panic
• ✅ test_inv_8_no_panics_across_all_fixtures: Zero panics across all fixtures (INV-8 verified)

INV-8 verified end-to-end

The test_inv_8_no_panics_across_all_fixtures test wraps all fixture parsing in std::panic::catch_unwind and verifies zero panics. This confirms INV-8 (no panic at the public boundary of pdftract-core).

Diagnostic catalog documented

File: crates/pdftract-core/src/diagnostics.rs

• ✅ Diagnostic struct exists with { code, byte_offset, object_ref, message }
• ✅ DiagCode enum with all variants following naming convention (STRUCT_, STREAM_, XREF_*, etc.)
• ✅ Each variant has /// doc comment explaining when it's emitted
• ✅ DIAGNOSTIC_CATALOG provides metadata (severity, recoverable, suggested action)
• ✅ emit! macro for ergonomic diagnostic emission

Adversarial fixtures

All 7 fixtures exist under tests/error_recovery/fixtures/:

• xref_30pct_bad_offsets.pdf
• missing_mediabox_all_pages.pdf
• missing_endobj.pdf
• combined_failures.pdf
• truncated_mid_stream.pdf
• int_overflow_bbox.pdf
• nested_failure.pdf

Each has a sibling .expected_diagnostics.json file.

Related Commits

• 6a35bdd: feat(pdftract-29z7b): implement unified diagnostic system + CLI commands
• 4d6fd8a: test(pdftract-4w0v4): implement adversarial test corpus + integration harness

Note on clippy errors

Pre-existing clippy warnings exist in the codebase (unrelated to Phase 1.6 work). The error recovery integration tests all pass, confirming the Phase 1.6 acceptance criteria are met.