Testing code reviewer

.github/workflows/code-review.yml

@@ -31,5 +31,7 @@ jobs:
           PR_NUMBER: ${{ github.event.pull_request.number }}
           REPO_NAME: ${{ github.repository }}
           COMMIT_SHA: ${{ github.event.pull_request.head.sha }}
+          BEFORE_SHA: ${{ github.event.before }}
+          EVENT_ACTION: ${{ github.event.action }}
         run: npm start
         working-directory: scripts

.gitignore

@@ -0,0 +1,2 @@
+node_modules/
+scripts/dist/

README.md

@@ -0,0 +1,105 @@
+# AI Code Reviewer
+
+A GitHub Actions bot that automatically reviews pull requests using the Claude API. When a PR is opened or updated, the bot fetches the diff, sends each changed file to Claude for analysis, and posts inline comments and a summary directly on the PR.
+
+The bot is based on the following guide: [cloudflare tutorials](https://developers.cloudflare.com/sandbox/tutorials/code-review-bot/)
+
+---
+
+## Setup
+
+### 1. Copy the workflow file
+
+Copy `.github/workflows/code-review.yml` into your target repository.
+
+### 2. Copy the scripts folder
+
+Copy the entire `scripts/` folder into the root of your target repository.
+
+### 3. Add the API key secret
+
+In your repository go to **Settings → Secrets and variables → Actions** and add:
+
+| Secret name | Value |
+|---|---|
+| `ANTHROPIC_API_KEY` | Your API key from [console.anthropic.com](https://console.anthropic.com) |
+
+`GITHUB_TOKEN` is provided automatically by GitHub Actions, you do not need to add it.
+
+### 4. That's it
+
+Open a pull request and the bot will trigger automatically.
+
+---
+
+## What the bot reviews
+
+- Only files changed in the PR
+- On a re-push to an existing PR, only files changed in that specific push (not the whole PR again)
+
+## What the bot skips
+
+- `package-lock.json` and all `*.lock` files
+- Anything inside a `dist/` directory
+
+To add more exclusions, edit the `IGNORED_FILES` regex in `scripts/src/constants.ts`.
+
+---
+
+## Customising the review instructions
+
+The prompt that controls what Claude focuses on lives in `scripts/src/constants.ts` as `REVIEW_INSTRUCTIONS`. Edit it to change the tone, focus areas, or output format.
+
+---
+
+## Project flow
+
+### Entry point
+
+GitHub Actions triggers the workflow in `.github/workflows/code-review.yml` whenever a PR is opened or a new commit is pushed to one. The workflow checks out the code, installs dependencies, and runs:
+
+```
+npm start  →  tsx src/review.ts
+```
+
+### `scripts/src/review.ts` — orchestrator
+
+This is where execution begins. `main()` calls the other modules in order:
+
+1. `getPRFiles()` — fetch the files to review
+2. `reviewFile()` — send each file to Claude
+3. `postReview()` — post inline comments on the PR
+4. `postSummary()` — post a top-level summary comment
+
+### `scripts/src/github.ts` — GitHub API
+
+Handles all communication with GitHub:
+
+- **`getPRFiles()`** — decides which files to fetch. On a new PR (`opened`) it fetches all changed files via `listFiles`. On a re-push (`synchronize`) it uses `compareCommits` between the previous and new SHA so only the files touched in that push are reviewed. Both paths filter out ignored files and parse each patch into a `DiffFile`.
+- **`parseValidLines()`** — reads the raw unified diff and builds a `Set<number>` of line numbers that actually exist in the new version of the file. Used to drop any comment Claude returns that references a line outside the diff.
+- **`postReview()`** — posts all inline comments as a single GitHub review. If the batch call fails (e.g. one bad line number slipped through), it falls back to posting each comment individually so the rest are not lost.
+- **`postSummary()`** — posts a top-level PR comment with a count of issues found per file, or a "no issues found" message if Claude had nothing to say.
+
+### `scripts/src/claude.ts` — Claude API
+
+Contains a single function `reviewFile()` which:
+
+1. Sends the file path and its diff patch to `claude-sonnet-4-6` with the review instructions as a cached system prompt
+2. Strips any markdown fences from the response (Claude sometimes wraps JSON in fences despite being told not to)
+3. Parses the JSON array of comments
+4. Filters out any comment whose `path` doesn't match the file being reviewed or whose `line` is not in the valid line set
+
+### `scripts/src/constants.ts` — static config
+
+Holds three exports used across the other modules:
+
+- `REVIEW_INSTRUCTIONS` — the system prompt sent to Claude on every call
+- `IGNORED_FILES` — the regex used to filter out generated and lock files
+- `MODEL` — the Claude model name, in one place so it's easy to change
+
+### `scripts/src/types.ts` — shared types
+
+Defines two interfaces used across all modules:
+
+- `DiffFile` — a changed file with its filename, raw patch string, and the set of valid line numbers
+- `ReviewComment` — a single comment with a file path, line number, and body text