Journal — Implementation Log

You maintain the .journal/ directory — a chronological log of all implementation work.

Entry Format

Each phase entry follows this structure:

---

## Phase {N}: {Short Title}

**Date:** {YYYY-MM-DD}
**Task:** {.todo/file.md -- Section name, or "Ad-hoc" if no .todo item}
**Upstream:** {src/Path/To/UpstreamFile.ts, or "N/A" for OXC-specific work}

{1-2 paragraph technical narrative. Key decisions, patterns, trade-offs. Note any divergences from upstream.}

### New files:

| File                                                     | Description   |
| -------------------------------------------------------- | ------------- |
| `crates/oxc_react_compiler/src/path/to/file.rs`         | Brief purpose |

### Modified files:

| File                                                     | Change       |
| -------------------------------------------------------- | ------------ |
| `crates/oxc_react_compiler/src/path/to/file.rs`         | What changed |

Rules

1. Phase numbers are sequential — increment from the latest entry
2. Date format — YYYY-MM-DD
3. Task links to .todo/ when applicable
4. Upstream references — note the corresponding TypeScript file(s) from babel-plugin-react-compiler
5. Narrative is technical — what was built, key decisions, patterns, divergences from upstream. No fluff.
6. File tables are exhaustive — every new and modified file
7. Omit empty sections — skip "New files" if none exist, same for "Modified files"
8. Split at ~50 entries — create new numbered file, update index
9. Reverse-chronological — newest entries at top of file
10. Separate with --- — horizontal rule between entries

Index Format

.journal/index.md:

# Implementation Journal

> Chronological log of implementation sessions. Each file covers ~50 entries before splitting.

| File             | Entries | Phases | Notes                                            |
| ---------------- | ------- | ------ | ------------------------------------------------ |
| [001.md](001.md) | N       | X–Y    | Brief summary of what this file covers           |

Workflow

Recording work

1. Run git diff --stat HEAD~1 and git log --oneline -5 to see changes
2. Read .journal/index.md to find latest file and phase number
3. Read the latest .journal/*.md to confirm current phase
4. Write new entry at the top of the latest file (after the header)
5. Update index if entry count changed or new file created

Splitting files

When a file reaches ~50 entries:

1. Create next numbered file with header # Implementation Journal — Part N
2. Add to .journal/index.md with phase range
3. Continue in the new file