relayburn-reader: port Claude Code parser (#255)

[willwashburn]

Summary

• The synchronous parser, incremental parser, and cross-file reconciler shipped in PRs relayburn-reader: port Claude Code parser core (#255) #262 and relayburn-reader: port parseClaudeSessionIncremental to Rust (#255) #265 (both merged); this PR ports the remaining packages/reader/src/claude.test.ts cases into native cargo test assertions so the Rust port now gates on the same shared tests/fixtures/claude/ JSONL inputs as the TS suite.
• Adds 35 new conformance tests covering tool-call back-population, fidelity coverage, compaction events, user-turn block sizing, content capture, and the full fork / continuation relationship suite — including in-memory evidence pairs that exercise the dedup paths in reconcile_claude_session_relationships.
• Two judgment calls (also documented inline): user-turn token counts assert the heuristic shape because cl100k is not wired in Rust yet (tracked in [Rust port] relayburn-sdk: embedding API mirroring TS surface #246), and the relationship dedup test reproduces the canonical key inline rather than crossing the reader/ledger crate boundary, matching the TS test's own workaround.

Test plan

• cargo test -p relayburn-reader (199 pass; 51 in claude::)
• cargo build --workspace clean
• cargo test --workspace green
• pnpm run build && pnpm run test (873 TS tests still pass)
• cargo fmt --check and cargo clippy --tests clean on the new code (pre-existing warnings on this file untouched)

Closes #255.

[coderabbitai]

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ℹ️ Recent review info

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Review profile: CHILL

Plan: Pro Plus

Run ID: 1a0d1e23-4fda-4b0e-a9df-d97f4644c546

📥 Commits

Reviewing files that changed from the base of the PR and between 7c7ce35 and 0150288.

📒 Files selected for processing (1)

• crates/relayburn-reader/src/claude.rs

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📝 Walkthrough

Walkthrough

This PR adds 1,160 lines of conformance test cases to the Claude session parser (claude.rs), validating synchronous and incremental parsing, content capture modes, token sizing heuristics, tool-call metadata backfilling, fidelity classification, relationship emission (root/subagent), system notifications, fork/continuation logic, and cross-file reconciliation with deduplication.

Changes

Claude Parser Conformance Tests

Layer / File(s)	Summary
Test Imports crates/relayburn-reader/src/claude.rs (lines 3042)	Expanded imports to include FidelityClass and UserTurnBlockKind for test assertions.
Synchronous Parsing & Metadata crates/relayburn-reader/src/claude.rs (lines 3704–4033)	Added tests validating project/usage surface parsing, multi-block deduplication, stable args_hash, tool-call error backfilling, replacement metadata propagation, edit hash extraction, tool-result event chronology, root/subagent relationship emission, system subagent notifications, and fidelity/compaction event behavior.
Token Sizing & Heuristics crates/relayburn-reader/src/claude.rs (lines 4035–4177)	Added tests for user-turn block sizing, token heuristics (including cl100k non-wired expectations), explicit heuristic tokenizer opt-in, and user-turn record emission for text sessions.
Content Capture Modes crates/relayburn-reader/src/claude.rs (lines 4179–4315)	Added tests for content mode defaults, hash-only behavior, full content capture for user/assistant text, chronological interleaving preservation, and tool_use block surfacing in assistant content.
Fork & Continuation Relationships crates/relayburn-reader/src/claude.rs (lines 4328–4525)	Added tests for resume marker relationships, provenance with differing basenames vs. in-log IDs, explicit continuedFrom/fork session ID handling, reconciliation edge skipping, first_parent_uuid gating, and cross-file evidence requirements.
Cross-File Reconciliation crates/relayburn-reader/src/claude.rs (lines 4557–4683)	Added tests validating parent UUID evidence spanning files, continuation emission for cross-file parent matches, fork row emission when files share a source session ID, and strict continuation case handling without fork emission.
Deduplication & Stability crates/relayburn-reader/src/claude.rs (lines 4729–4861)	Added tests ensuring relationship dedup keys remain stable across re-parses, reconciliation avoids duplicate continuation edges for local /resume references, and subagent rows carry provenance when basename differs from in-log session ID.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~30 minutes

Possibly related issues

• [Rust port] relayburn-reader: Claude Code parser (claude.rs) #255 — [Rust port] relayburn-reader: Claude Code parser (claude.rs): This PR fulfills the conformance gate requirement by implementing the full test suite that validates parseClaudeSession, parseClaudeSessionIncremental, and reconcileClaudeSessionRelationships against all expected scenarios from the original TypeScript test suite.
• [Rust port] relayburn-reader: parsers + classifier #242 — Rust port foundation: This PR builds on the foundational port infrastructure (types, hash, classifier modules) to deliver the complete Claude parser conformance validation.

Poem

🐰 Hippity-hop through test forests so green,
Each assertion a carrot, each fixture pristine,
From forks to continuations, the parser now gleams—
A warren of tests fulfilling our schemes! ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'relayburn-reader: port Claude Code parser (#255)' clearly and specifically summarizes the main objective—porting the Claude Code parser to Rust—matching the changeset's focus on adding test coverage for the claude.rs module.
Description check	✅ Passed	The description comprehensively documents the porting effort, listing specific test categories added, documented trade-offs, test results, and issue closure, all directly relevant to the changeset of extending claude.rs test coverage.
Linked Issues check	✅ Passed	The PR fulfills issue #255 acceptance criteria: it expands claude.rs test coverage to match packages/reader/src/claude.test.ts, implements 35 new conformance tests covering tool-call, fidelity, relationships and other specified domains, and reports passing the full test suite against shared fixtures.
Out of Scope Changes check	✅ Passed	All changes are scoped to extending claude.rs test coverage (imports, conformance tests) directly addressing issue #255's requirement to port test cases and achieve byte-identical output on shared fixtures.
Docstring Coverage	✅ Passed	Docstring coverage is 94.74% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch claude/close-issue-255-claude-parser

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