Prettier Module

The problem

Prettier is easy to install and easy to get wrong in a way that shows up weeks later: a printWidth of 80 in one repository and 100 in another, singleQuote toggled per team, and a .prettierignore that does not list dist/, so pnpm format reformats three thousand build artefacts.

The second problem is the interaction with ESLint. If ESLint still carries the deprecated formatting rules, both tools rewrite the same line and the diff becomes noise.

The command

npx create-devflow --only prettier

Generated files

.prettierrc.json

{
  "semi": true,
  "singleQuote": true,
  "trailingComma": "all",
  "printWidth": 100,
  "tabWidth": 2,
  "arrowParens": "always",
  "endOfLine": "lf"
}

.prettierignore

dist/
build/
node_modules/
coverage/
.next/
.nuxt/
pnpm-lock.yaml
package-lock.json
yarn.lock

Packages installed

Scripts added

format:check is the one to run in CI — it fails on unformatted files without rewriting them, which is exactly what a pull request check should do.

Manual setup versus DevFlow

The manual version is npm i -D prettier, npx prettier --init, and then a .prettierignore you write from memory. The .prettierinit wizard writes a config, but it does not write an ignore file, and it does not add the npm scripts, so the next repository starts from zero again.

DevFlow writes the config, the ignore file and the scripts in one step, with the same values in every repository.

Limits

• The style is a fixed baseline. 100 columns, single quotes, semicolons, trailing commas, LF line endings. It is a sane, widely used default — it is not your house style. Edit .prettierrc.json after generation; it is never overwritten on re-runs.
• No .editorconfig integration. Prettier does not read .editorconfig by default. The EditorConfig module writes a matching .editorconfig if you want editors to agree with the formatter.
• No conflict with ESLint is required, but you should check it. If your existing ESLint config still enables formatting rules such as indent or quotes, the two tools will disagree. The ESLint, Prettier and Husky guide shows the exact fix.
• Conflicts with Biome. The Biome module replaces Prettier entirely, so the wizard blocks the pair.

FAQ

Does DevFlow overwrite my existing Prettier config?

No. .prettierrc.json and .prettierignore are created with skip-if-exists semantics. An existing .prettierrc, prettier.config.js or prettier.config.mjs is left alone.

Does Prettier conflict with ESLint?

Not with the configuration DevFlow generates — it contains no stylistic rules. It can conflict with a hand-written ESLint config that still enables the deprecated formatting rules. The guide explains how to remove them.

Which package manager does format use?

None. The script calls the prettier binary from node_modules/.bin, so it works identically with npm, pnpm, yarn and bun.

Related

• ESLint module — the linter that pairs with this formatter
• lint-staged module — format only the files you changed
• ESLint, Prettier and Husky setup for React and TypeScript
• CLI reference