ember-tooling
prettier-plugin-ember-template-tag
A Prettier plugin for formatting Ember template tags in both .gjs and .gts files. See also Ember Template Imports.
Compatibility
Prettier 3.0.0 and above
IMPORTANT! If you are running Prettier via eslint-plugin-ember and eslint-plugin-prettier1:
| eslint-plugin-ember | prettier-plugin-ember-template-tag |
|---|---|
| <12 | 1.1.0 |
| >=12 | 2+ |
1 Neither I nor the Prettier project recommend running Prettier this way.
Usage
Install:
NPM:
npm install --save-dev prettier prettier-plugin-ember-template-tagYarn:
yarn add --dev prettier prettier-plugin-ember-template-tagPNPM:
pnpm add --save-dev prettier prettier-plugin-ember-template-tagConfigure prettier using your preferred method. For example, with
.prettierrc.js:// .prettierrc.js module.exports = { // ... plugins: ['prettier-plugin-ember-template-tag'], overrides: [ { files: '*.{js,ts,gjs,gts}', options: { singleQuote: true, }, }, // ... ], };If you already have a
"prettier"section inpackage.json, remember that takes precedence over the.prettierrc.jsfile!Run prettier on your codebase
# With prettier >= 3.1 npm prettier --write . # With prettier < 3.1 # See <https://github.com/gitKrystan/prettier-plugin-ember-template-tag/issues/113> and # <https://github.com/prettier/prettier/issues/15351> for details on why using the # `--plugin` flag is required here. npm prettier --write . --plugin prettier-plugin-ember-template-tag
Opinions
This plugin works by weaving together Prettier's standard babel-ts and glimmer parsers, so it doesn't have many opinions of its own. With that said, I did have to make some opinionated decisions regarding how templates are printed within the JavaScript. In general, my strategy has been to ask "What would a function do?" since functions can be used in the same positions as the <template> tag.
Semicolons
Semicolons will be included or omitted as follows:
export default class MyComponent extends Component {
<template>Hello</template> // omit
}
<template>Hello</template> // omit
export default <template>Hello</template> // omit
export const MyComponent = <template>Hello</template>; // include by default, omit in no-semi modeYou can read more about and comment on my semicolon decision process on this RFC.
New Lines
Template tags will always be printed on their own line for templates that are default exports or top-level class templates. Templates used as expressions will be allowed to collapse onto a single line if they fit:
import Component from '@glimmer/component';
const what = <template>Used as an expression</template>;
export const who = <template>Used as an expression</template>;
<template>
The default export
</template>
class MyComponent extends Component {
<template>
Top-level class template
</template>
}export default
The following <template> invocations both desugar to default exports:
// template-only-component.js
<template>Hello</template>;
// or
export default <template>Hello</template>;By default, this plugin will remove export default to print the more concise "sugared" default export template. If you would prefer to always include export default, you can enable the templateExportDefault option described below.
Configuration
These configuration options are available in addition to Prettier's standard config for JavaScript and Handlebars files.
| Name | Default | Description |
|---|---|---|
templateExportDefault |
false |
If true, default export template tags will be prepended with export default. |
templateSingleQuote |
undefined | Same as in Prettier but affecting only template tags. If undefined, will fall back to whatever is set for the global singleQuote config. |
Editor integration
VSCode
- Install Prettier and this plugin as shown above.
- Install the
Prettier - Code FormatterVSCode Extension. - Reload your VSCode window.
The format command and format-on-save should now work for
.gjsand.gtsfiles. You might need to wait a few seconds for the Prettier extension to register the plugin. If this does not work, you can manually set Prettier as the default formatter for.gjsand.gtsas shown below, like so, but please file an issue if you need to do this:// .vscode/settings.json { "[gjs]": { // "editor.formatOnSave": true, "editor.defaultFormatter": "esbenp.prettier-vscode" }, "[gts]": { // "editor.formatOnSave": true, "editor.defaultFormatter": "esbenp.prettier-vscode" } }If you're still having issues, check out this issue for troubleshooting ideas and comment there with what ends up working.
Ignoring code
Because gts/gjs files include both JavaScript and Glimmer template code, you'll need to use the appropriate prettier-ignore comment for the code you are ignoring:
export default class MyComponent extends Component {
// prettier-ignore
cells = matrix(
1, 0, 0,
0, 1, 0,
0, 0, 1
)
<template>
{{! prettier-ignore }}
{{#each this.cells as |cell|}}{{cell.contents}}{{/each}}
</template>
}To ignore the entire template, use a JavaScript //prettier-ignore comment before the opening <template> tag:
export default class MyComponent extends Component {
// prettier-ignore
<template>
This whole template is ignored
<MyUglyComponent "shall" be="preserved">
<ThisPart
is = "also preserved as is"
/>
</MyUglyComponent>
</template>
}Bugs
If you find a bug, please file a bug report! See CONTRIBUTING.md for more details.