dsh-format-after-edit
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Agents don't run your formatter. They write code with their own idea of quotes, wrapping and trailing commas, and you find out at review time, or when CI's format check fails and the agent spends a turn "fixing" whitespace. Telling it to run Prettier after every edit works until it forgets.
This DeepSeek Harness plugin runs the project's own formatter on each file right after the agent writes or edits it. When the formatter changes the file, the model is told, so its next edit doesn't target text that has moved:
The file src/api/client.ts has been updated successfully.
[dsh-format-after-edit] prettier reformatted src/api/client.ts (4 lines changed). Re-read the file
before editing it again, since text you saw earlier may have moved or changed.
When the formatter fails, which usually means the edit broke the syntax, the model sees why:
[dsh-format-after-edit] ruff could not format app/models.py. Your edit was saved, but this often
means it has a syntax error:
error: Failed to parse app/models.py:14:5: Expected an indented block after function definition
Install
dsh plugin --profile web add dsh-format-after-edit
That's the web profile, the browser UI you start with dsh web. If you run DSH another way, use headless (scripts and CI) or acp (editor integrations) instead. Each profile keeps its own plugin list, so add it to every profile you use. It's on as soon as it's installed. Remove it with dsh plugin --profile web remove dsh-format-after-edit.
It's also part of dsh-guard-pack, which installs nine guards at once.
Which formatter runs
The one your project is set up for. A formatter runs only when the project has its config and the tool is installed locally or on your PATH. Nothing is ever downloaded, so a repo without a formatter is left alone.
| Files | Formatter | When |
|---|
| JS, TS, JSON, CSS, Markdown, YAML, HTML, Vue, Svelte... | Prettier | .prettierrc*, prettier.config.* or a "prettier" key in package.json, and prettier in node_modules |
| JS, TS, JSON, CSS, GraphQL... | Biome | biome.json(c), and @biomejs/biome in node_modules |
| Anything dprint has plugins for | dprint | dprint.json or .dprint.json(c), and dprint in node_modules |
| Python | Ruff | ruff.toml, .ruff.toml or [tool.ruff] in pyproject.toml, and ruff in the venv or on PATH |
| Python | Black | [tool.black] in pyproject.toml, and black in the venv or on PATH |
| Go | gofmt | a go.mod, and gofmt on PATH |
| Rust | rustfmt | a Cargo.toml (its edition is used), and rustfmt on PATH |
| C, C++, Objective-C, protobuf | clang-format | a .clang-format, and clang-format on PATH |
The closest config wins, so a monorepo package with its own biome.json uses Biome even if the root has a .prettierrc. Each formatter's own ignore file (.prettierignore, Biome's files.ignore...) is respected. Lockfiles, node_modules, dist, build, vendor and minified files are never touched.
Your own formatter
For anything else, add a command. {file} becomes the edited file's path, quoted. Custom entries are checked before the built-in ones.
- id: format-after-edit
config:
custom:
- files: ['*.php']
command: vendor/bin/pint {file}
- files: ['*.java']
command: google-java-format --replace {file}
- files: ['**/*.tf']
command: terraform fmt {file}
Settings
The easy way: open Plugins in DSH's sidebar, click dsh-format-after-edit, change what you want and press Save. Custom commands go in cordis.patch.yml.
Add a row like this to ~/.dsh/profiles/<profile>/cordis.patch.yml, or to ~/.dsh/cordis.patch.yml for every profile. Keys you leave out keep their defaults.
- id: format-after-edit
config:
formatters: [prettier, biome, dprint, ruff, black, gofmt, rustfmt, clang-format]
custom: []
ignore: ['**/node_modules/**', '**/dist/**', '*.lock'] # replaces the default list
tools: [write, edit, str_replace_editor]
timeoutMs: 20000
reportChanges: true # tell the model when the file changed
reportErrors: true # tell the model when the formatter failed
Development
npm install # from the repository root
npm test -w packages/dsh-format-after-edit
npm run test:e2e # real dsh runs against a scripted local model, no API key needed
MIT licensed. Written by acus9345. Bug reports and ideas are welcome in the issues.
