# cargo-dejadoc
[](https://github.com/LucaCappelletti94/cargo-dejadoc/actions/workflows/ci.yml)
[](https://codecov.io/github/LucaCappelletti94/cargo-dejadoc)
[](https://sonarcloud.io/summary/new_project?id=lucacappelletti94-github_LucaCappelletti94_cargo-dejadoc)
[](https://crates.io/crates/dejadoc)
[](https://docs.rs/dejadoc)
Whoa, deja vu. A doctest went past us, and then another that looked just like it.
`cargo dejadoc` scans and canonicalizes every doctest your workspace's rustdoc would run, reporting any identified duplicates. Items are kept by their `cfg` as rustdoc sees them on a 64-bit Linux host with every feature on, `test` off and custom cfgs off.
The flags under `cargo dejadoc --help` restrict the package, set the threshold and minimum token count, point at a config file, and switch the output to JSON.
Without flags, parameters come from `.dejadoc.toml` at the workspace root.
To allow a known copy, add the `dejadoc` token to the fence's info list, as in `rust,dejadoc`. rustdoc runs the doctest and ignores the unknown token, so nothing else about the site changes.
In CI, the composite action installs the crate and runs the gate.
```yaml
- uses: LucaCappelletti94/cargo-dejadoc@v1
with:
threshold: 2
```
In a pull request, the action posts the findings as a review instead of failing the job.
```yaml
on: pull_request
jobs:
dejadoc:
runs-on: ubuntu-latest
permissions:
pull-requests: write
steps:
- uses: actions/checkout@v4
- uses: dtolnay/rust-toolchain@stable
- uses: LucaCappelletti94/cargo-dejadoc@v1
with:
pr-number: ${{ github.event.pull_request.number }}
```
Every duplicated doctest whose file is in the pull request diff gets an inline comment naming the copy count and the kept original, the first copy marked as the one to keep and each later copy with a suggestion that deletes it, and the review requests changes. Each comment ends with a link that opens a prefilled issue here for reporting a wrong review and a heart link to support the project. Sites outside the diff get no comment, and when no site is in the diff the review is skipped.
A pull request from a fork runs with a read-only `GITHUB_TOKEN`, so the action logs a warning, skips the review, and the job passes. To review fork pull requests, trigger on `pull_request_target` and check out the pull request head as below. That trigger runs the job with write access, so read [GitHub's guidance](https://docs.github.com/en/actions/reference/security/securely-using-pull_request_target) before opting the checkout in with `allow-unsafe-pr-checkout`.
```yaml
on: pull_request_target
jobs:
dejadoc:
runs-on: ubuntu-latest
permissions:
pull-requests: write
steps:
- uses: actions/checkout@v7
with:
ref: ${{ github.event.pull_request.head.sha }}
allow-unsafe-pr-checkout: true
- uses: dtolnay/rust-toolchain@stable
- uses: LucaCappelletti94/cargo-dejadoc@v1
with:
pr-number: ${{ github.event.pull_request.number }}
```
On a private repository, the setting **Send write tokens to workflows from pull requests** under Settings > Actions > General does the same without changing the trigger.
The library builds the same report in memory.
```rust
let report = dejadoc::Dejadoc::default().run("tests/fixtures/dupws").unwrap();
assert_eq!(report.groups.len(), 2);
```