fte.js-formatter

Formatter & Linter for FTE templates (.nhtml). Provides importable API and CLI.

Install (workspace)

This repo uses pnpm workspaces. In external apps:

npm i -D fte.js-formatter

CLI

# format stdin -> stdout
cat template.nhtml | fte-format > formatted.nhtml

# format files in-place
fte-format --write demo/**/*.nhtml

# check (CI)
fte-format --check demo/**/*.nhtml

API

import { format, lint } from 'fte.js-formatter'

const source = `<# block main : #> Hello <# end #>`
const pretty = format(source)

const issues = lint(source)
// [{ ruleId: 'end-on-own-line', ... }, ...]

Rules (Linter)

• directive-on-own-line: <#@ ... #> only content on line
• block/slot-on-own-line: <# block ... : #>, <# slot ... : #> only content on line
• end-on-own-line: <# end #> only content on line
• code-on-own-line: <% ... %>, <%= ... %>, <%- ... %> only content on line
• comment-on-own-line: <* ... *> not inline with other content
• one-construct-per-line: only one template construct per line
• no-trailing-whitespace
• final-newline
• no-empty-expression: #{} or !{} not allowed
• no-empty-code: <% %>, <# #> not allowed

Formatting

• Splits constructs so there is one construct per line
• Indents content inside block/slot with 2 spaces by default (configurable)
• Collapses multiple blank lines to a single blank line
• Trims trailing spaces; ensures final newline

Options

type FormatOptions = {
  indent?: number | 'tab'
  ensureFinalNewline?: boolean
  trimTrailingWhitespace?: boolean
}

Notes

• Parser-backed checks are used when fte.js-parser is available; otherwise, safe fallbacks are applied.
• Rules are conservative to avoid breaking semantics; please open issues for edge cases.