kdu-eslint-parser
The ESLint custom parser for .kdu
files.
⤴️ Motivation
This parser allows us to lint the <template>
of .kdu
files. We can make mistakes easily on <template>
if we use complex directives and expressions in the template. This parser and the rules of eslint-plugin-kdu would catch some of the mistakes.
💿 Installation
npm install --save-dev eslint kdu-eslint-parser
- Requires Node.js ^12.22.0, ^14.17.0, 16.0.0 or later.
- Requires ESLint 6.0.0 or later.
📖 Usage
- Write
parser
option into your.eslintrc.*
file. - Use glob patterns or
--ext .kdu
CLI option.
{
"extends": "eslint:recommended",
"parser": "kdu-eslint-parser"
}
$ eslint "src/**/*.{js,kdu}"
# or
$ eslint src --ext .kdu
🔧 Options
parserOptions
has the same properties as what espree, the default parser of ESLint, is supporting.
For example:
{
"parser": "kdu-eslint-parser",
"parserOptions": {
"sourceType": "module",
"ecmaVersion": 2018,
"ecmaFeatures": {
"globalReturn": false,
"impliedStrict": false,
"jsx": false
}
}
}
parserOptions.parser
You can use parserOptions.parser
property to specify a custom parser to parse <script>
tags.
Other properties than parser would be given to the specified parser.
For example:
{
"parser": "kdu-eslint-parser",
"parserOptions": {
"parser": "@babel/eslint-parser",
"sourceType": "module"
}
}
{
"parser": "kdu-eslint-parser",
"parserOptions": {
"parser": "@typescript-eslint/parser",
"sourceType": "module"
}
}
You can also specify an object and change the parser separately for <script lang="...">
.
{
"parser": "kdu-eslint-parser",
"parserOptions": {
"parser": {
// Script parser for `<script>`
"js": "espree",
// Script parser for `<script lang="ts">`
"ts": "@typescript-eslint/parser",
// Script parser for kdu directives (e.g. `k-if=` or `:attribute=`)
// and kdu interpolations (e.g. `{{variable}}`).
// If not specified, the parser determined by `<script lang ="...">` is used.
"<template>": "espree",
}
}
}
If the parserOptions.parser
is false
, the kdu-eslint-parser
skips parsing <script>
tags completely.
This is useful for people who use the language ESLint community doesn't provide custom parser implementation.
parserOptions.kduFeatures
You can use parserOptions.kduFeatures
property to specify how to parse related to Kdu features.
For example:
{
"parser": "kdu-eslint-parser",
"parserOptions": {
"kduFeatures": {
"filter": true,
"interpolationAsNonHTML": true,
"styleCSSVariableInjection": true,
}
}
}
parserOptions.kduFeatures.filter
You can use parserOptions.kduFeatures.filter
property to specify whether to parse the Kdu2 filter. If you specify false
, the parser does not parse |
as a filter.
For example:
{
"parser": "kdu-eslint-parser",
"parserOptions": {
"kduFeatures": {
"filter": false
}
}
}
If you specify false
, it can be parsed in the same way as Kdu 3.
The following template parses as a bitwise operation.
<template>
<div>{{ a | b }}</div>
</template>
However, the following template that are valid in Kdu 2 cannot be parsed.
<template>
<div>{{ a | valid:filter }}</div>
</template>
parserOptions.kduFeatures.interpolationAsNonHTML
You can use parserOptions.kduFeatures.interpolationAsNonHTML
property to specify whether to parse the interpolation as HTML. If you specify true
, the parser handles the interpolation as non-HTML (However, you can use HTML escaping in the interpolation). Default is true
.
For example:
{
"parser": "kdu-eslint-parser",
"parserOptions": {
"kduFeatures": {
"interpolationAsNonHTML": true
}
}
}
If you specify true
, it can be parsed in the same way as Kdu 3.
The following template can be parsed well.
<template>
<div>{{a<b}}</div>
</template>
But, it cannot be parsed with Kdu 2.
parserOptions.kduFeatures.styleCSSVariableInjection
If set to true
, to parse expressions in k-bind
CSS functions inside <style>
tags. k-bind()
is parsed into the KExpressionContainer
AST node and held in the KElement
of <style>
. Default is true
.
🎇 Usage for custom rules / plugins
- This parser provides
parserServices
to traverse<template>
.-
defineTemplateBodyVisitor(templateVisitor, scriptVisitor, options)
... returns ESLint visitor to traverse<template>
. -
getTemplateBodyTokenStore()
... returns ESLintTokenStore
to get the tokens of<template>
. -
getDocumentFragment()
... returns the rootKDocumentFragment
. -
defineCustomBlocksVisitor(context, customParser, rule, scriptVisitor)
... returns ESLint visitor that parses and traverses the contents of the custom block. -
defineDocumentVisitor(documentVisitor, options)
... returns ESLint visitor to traverses the document.
-
- mustache-interpolation-spacing.js is an example.
defineTemplateBodyVisitor(templateBodyVisitor, scriptVisitor, options)
Arguments
-
templateBodyVisitor
... Event handlers for<template>
. -
scriptVisitor
... Event handlers for<script>
or scripts. (optional) -
options
... Options. (optional)-
templateBodyTriggerSelector
... Script AST node selector that triggers the templateBodyVisitor. Default is"Program:exit"
. (optional)
-
import { AST } from "kdu-eslint-parser"
export function create(context) {
return context.parserServices.defineTemplateBodyVisitor(
// Event handlers for <template>.
{
KElement(node: AST.KElement): void {
//...
}
},
// Event handlers for <script> or scripts. (optional)
{
Program(node: AST.ESLintProgram): void {
//...
}
},
// Options. (optional)
{
templateBodyTriggerSelector: "Program:exit"
}
)
}
⚠️ Known Limitations
Some rules make warnings due to the outside of <script>
tags.
Please disable those rules for .kdu
files as necessary.
- eol-last
- linebreak-style
- max-len
- max-lines
- no-trailing-spaces
- unicode-bom
- Other rules which are using the source code text instead of AST might be confused as well.
Development Tools
-
npm run build
compiles TypeScript source code toindex.js
,index.js.map
, andindex.d.ts
. -
npm run clean
removes the temporary files which are created bynpm run build
. -
npm run lint
runs ESLint. -
npm run setup
setups submodules to develop.