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Remove unnecessary parentheses around assignment in `v-on` (#16887 by @fisker)

<!-- Input -->
<template>
  <button @&#8203;click="foo += 2">Click</button>
</template>

<!-- Prettier 3.4.0 -->
<template>
  <button @&#8203;click="(foo += 2)">Click</button>
</template>

<!-- Prettier 3.4.1 -->
<template>
  <button @&#8203;click="foo += 2">Click</button>
</template>

`v3.4.0`

`v3.3.3`

Add parentheses for nullish coalescing in ternary (#16391 by @cdignam-segment)

This change adds clarity to operator precedence.

// Input
foo ? bar ?? foo : baz;
foo ?? bar ? a : b;
a ? b : foo ?? bar;

// Prettier 3.3.2
foo ? bar ?? foo : baz;
foo ?? bar ? a : b;
a ? b : foo ?? bar;

// Prettier 3.3.3
foo ? (bar ?? foo) : baz;
(foo ?? bar) ? a : b;
a ? b : (foo ?? bar);

Add parentheses for decorator expressions (#16458 by @y-schneider)

Prevent parentheses around member expressions or tagged template literals from being removed to follow the stricter parsing rules of TypeScript 5.5.

// Input
@&#8203;(foo`tagged template`)
class X {}

// Prettier 3.3.2
@&#8203;foo`tagged template`
class X {}

// Prettier 3.3.3
@&#8203;(foo`tagged template`)
class X {}

Support `@let` declaration syntax (#16474 by @sosukesuzuki)

Adds support for Angular v18 @let declaration syntax.

Please see the following code example. The @let declaration allows you to define local variables within the template:

@&#8203;let name = 'Frodo';

<h1>Dashboard for {{name}}</h1>
Hello, {{name}}

For more details, please refer to the excellent blog post by the Angular Team: Introducing @let in Angular.

We also appreciate the Angular Team for kindly answering our questions to implement this feature.

`v3.3.2`

Fix handlebars path expressions starts with `@` (#16358 by @Princeyadav05)

{{! Input }}
<div>{{@&#8203;x.y.z}}</div>

{{! Prettier 3.3.1 }}
<div>{{@&#8203;x}}</div>

{{! Prettier 3.3.2 }}
<div>{{@&#8203;x.y.z}}</div>

`v3.3.1`

Preserve empty lines in front matter (#16347 by @fisker)

<!-- Input -->
---
foo:
  - bar1

  - bar2

  - bar3
---
Markdown

<!-- Prettier 3.3.0 -->

---
foo:
  - bar1
  - bar2
  - bar3
---

Markdown

<!-- Prettier 3.3.1 -->
---
foo:
  - bar1

  - bar2

  - bar3
---

Markdown

Preserve explicit language in front matter (#16348 by @fisker)

<!-- Input -->
---yaml
title: Hello
slug: home
---

<!-- Prettier 3.3.0 -->
---
title: Hello
slug: home
---

<!-- Prettier 3.3.1 -->
---yaml
title: Hello
slug: home
---

Avoid line breaks in import attributes (#16349 by @fisker)

// Input
import something from "./some-very-very-very-very-very-very-very-very-long-path.json" with { type: "json" };

// Prettier 3.3.0
import something from "./some-very-very-very-very-very-very-very-very-long-path.json" with { type:
  "json" };

// Prettier 3.3.1
import something from "./some-very-very-very-very-very-very-very-very-long-path.json" with { type: "json" };

`v3.3.0`

`v3.2.5`

Support Angular inline styles as single template literal (#15968 by @sosukesuzuki)

Angular v17 supports single string inline styles.

// Input
@&#8203;Component({
  template: `<div>...</div>`,
  styles: `h1 { color: blue; }`,
})
export class AppComponent {}

// Prettier 3.2.4
@&#8203;Component({
  template: `<div>...</div>`,
  styles: `h1 { color: blue; }`,
})
export class AppComponent {}

// Prettier 3.2.5
@&#8203;Component({
  template: `<div>...</div>`,
  styles: `
    h1 {
      color: blue;
    }
  `,
})
export class AppComponent {}

Unexpected embedded formatting for Angular template (#15969 by @JounQin)

Computed template should not be considered as Angular component template

// Input
const template = "foobar";

@&#8203;Component({
  [template]: `<h1>{{       hello }}</h1>`,
})
export class AppComponent {}

// Prettier 3.2.4
const template = "foobar";

@&#8203;Component({
  [template]: `<h1>{{ hello }}</h1>`,
})
export class AppComponent {}

// Prettier 3.2.5
const template = "foobar";

@&#8203;Component({
  [template]: `<h1>{{       hello }}</h1>`,
})
export class AppComponent {}

Use `"json"` parser for `tsconfig.json` by default (#16012 by @sosukesuzuki)

In v2.3.0, we introduced "jsonc" parser which adds trialing comma by default.

When adding a new parser we also define how it will be used based on the linguist-languages data.

tsconfig.json is a special file used by TypeScript, it uses .json file extension, but it actually uses the JSON with Comments syntax. However, we found that there are many third-party tools not recognize it correctly because of the confusing .json file extension.

We decide to treat it as a JSON file for now to avoid the extra configuration step.

To keep using the "jsonc" parser for your tsconfig.json files, add the following to your .pretterrc file

{
  "overrides": [
    {
      "files": ["tsconfig.json", "jsconfig.json"],
      "options": {
        "parser": "jsonc"
      }
    }
  ]
}

`v3.2.4`

Fix incorrect parser inference (#15947 by @fisker)

Files like .eslintrc.json were incorrectly formatted as JSONC files.

// Input
prettier --file-info .eslintrc.json
{ "ignored": false, "inferredParser": "jsonc" }

// Prettier 3.2.4
prettier --file-info .eslintrc.json
{ "ignored": false, "inferredParser": "json" }

`v3.2.3`

Throw errors for invalid code (#15881 by @fisker, @Josh-Cena, @auvred)

// Input
1++;

// Prettier 3.2.2
1++;

// Prettier 3.2.3
SyntaxError: Invalid left-hand side expression in unary operation (1:1)
> 1 | 1++;
    | ^

// Input
try {} catch (error = 1){}

// Prettier 3.2.2
try {
} catch (error) {}

// Prettier 3.2.3
SyntaxError: Catch clause variable cannot have an initializer. (1:23)
> 1 | try {} catch (error = 1){}
    |                       ^

Fix parser inference (#15927 by @fisker)

// Prettier 3.2.2
prettier --file-info tsconfig.json
{ "ignored": false, "inferredParser": "json" }

// Prettier 3.2.3
prettier --file-info tsconfig.json
{ "ignored": false, "inferredParser": "jsonc" }

`v3.2.2`

Fix crash when parsing template literal CSS in a JSX style tag using a spread attribute (#15896 by @eelco)

For example this code would crash before:

<style {...spread}>{`.{}`}</style>

Fix formatting error on optional call expression and member chain (#15920 by @sosukesuzuki)

// Input
a(() => {}, c?.d());

// Prettier 3.2.1
TypeError: Cannot read properties of undefined (reading 'type')

// Prettier 3.2.2
a(() => {}, c?.d());

`v3.2.1`

Fix formatting error on member chain (#15915 by @sosukesuzuki)

// Input
test().test2().test2(thing?.something);

// Prettier 3.2.0
TypeError: Cannot read properties of undefined (reading 'type')

// Prettier 3.2.1
test().test2().test2(thing?.something);

`v3.2.0`

`v3.1.1`

Fix config file search (#15363 by @fisker)

Previously, we start search for config files from the filePath as a directory, if it happened to be a directory and contains config file, it will be used by mistake.

├─ .prettierrc
└─ test.js         (A directory)
  └─ .prettierrc

// Prettier 3.1.0
await prettier.resolveConfigFile(new URL("./test.js", import.meta.url));
// <CWD>/test.js/.prettierrc

// Prettier 3.1.1
await prettier.resolveConfigFile(new URL("./test.js", import.meta.url));
// <CWD>/.prettierrc

Skip explicitly passed symbolic links with `--no-error-on-unmatched-pattern` (#15533 by @sanmai-NL)

Since Prettier v3, we stopped following symbolic links, however in some use cases, the symbolic link patterns can't be filtered out, and there is no way to prevent Prettier from throwing errors.

In Prettier 3.1.1, you can use --no-error-on-unmatched-pattern to simply skip symbolic links.

Consistently use tabs in ternaries when `useTabs` is `true` (#15662 by @auvred)

// Input
aaaaaaaaaaaaaaa
	? bbbbbbbbbbbbbbbbbb
	: ccccccccccccccc
	  ? ddddddddddddddd
	  : eeeeeeeeeeeeeee
	    ? fffffffffffffff
	    : gggggggggggggggg;

// Prettier 3.1.0
aaaaaaaaaaaaaaa
	? bbbbbbbbbbbbbbbbbb
	: ccccccccccccccc
	  ? ddddddddddddddd
	  : eeeeeeeeeeeeeee
	    ? fffffffffffffff
	    : gggggggggggggggg;

// Prettier 3.1.1
aaaaaaaaaaaaaaa
	? bbbbbbbbbbbbbbbbbb
	: ccccccccccccccc
		? ddddddddddddddd
		: eeeeeeeeeeeeeee
			? fffffffffffffff
			: gggggggggggggggg;

Improve config file search (#15663 by @fisker)

The Prettier config file search performance has been improved by more effective cache strategy.

Fix unstable and ugly formatting for comments in destructuring patterns (#15708 by @sosukesuzuki)

// Input
const {
  foo,
  // bar
  // baz
}: Foo = expr;

// Prettier 3.1.0
const {
  foo1,
} // bar
// baz
: Foo = expr;

// Prettier 3.1.0 second output
const {
  foo1, // bar
} // baz
: Foo = expr;

// Prettier 3.1.1
const {
  foo1,
  // bar
  // baz
}: Foo = expr;

Support "Import Attributes" (#15718 by @fisker)

TypeScript 5.3 supports the latest updates to the import attributes proposal.

import something from "./something.json" with { type: "json" };

Fix false claim in docs that cursorOffset is incompatible with rangeStart/rangeEnd (#15750 by @ExplodingCabbage)

The cursorOffset option has in fact been compatible with rangeStart/rangeEnd for over 5 years, thanks to work by @ds300. However, Prettier's documentation (including the CLI --help text) continued to claim otherwise, falsely. The documentation is now fixed.

Keep curly braces and `from` keyword in empty `import` statements (#15756 by @fisker)

// Input
import { } from 'foo';
import { /* comment */ } from 'bar';

// Prettier 3.1.0
import {} from "foo";
import /* comment */ "bar";

// Prettier 3.1.1
import {} from "foo";
import {} from /* comment */ "bar";

Keep empty import attributes and assertions (#15757 by @fisker)

// Input
import foo from "foo" with {};
import bar from "bar" assert {};

// Prettier 3.1.0
import foo from "foo";
import bar from "bar";

// Prettier 3.1.1
import foo from "foo" with {};
import bar from "bar" assert {};

`v3.1.0`

`v3.0.3`

Add `preferUnplugged: true` to `package.json` (#15169 by @fisker and @so1ve)

Prettier v3 uses dynamic imports, user will need to unplug Prettier when Yarn's PnP mode is enabled, add preferUnplugged: true to package.json, so Yarn will install Prettier as unplug by default.

Support shared config that forbids `require()` (#15233 by @fisker)

If an external shared config package is used, and the package exports don't have require or default export.

In Prettier 3.0.2 Prettier fails when attempt to require() the package, and throws an error.

Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: No "exports" main defined in <packageName>/package.json

Allow argument of `require()` to break (#15256 by @fisker)

// Input
const plugin = require(
  global.STANDALONE
    ? path.join(__dirname, "../standalone.js")
    : path.join(__dirname, "..")
);

// Prettier 3.0.2
const plugin = require(global.STANDALONE
  ? path.join(__dirname, "../standalone.js")
  : path.join(__dirname, ".."));

// Prettier 3.0.3
const plugin = require(
  global.STANDALONE
    ? path.join(__dirname, "../standalone.js")
    : path.join(__dirname, "..")
);

Do not print trailing commas in arrow function type parameter lists in `ts` code blocks (#15286 by @sosukesuzuki)

<!-- Input -->
```ts
const foo = <T>() => {}
```

<!-- Prettier 3.0.2 -->
```ts
const foo = <T,>() => {}
```

<!-- Prettier 3.0.3 -->
```ts
const foo = <T>() => {}
```

Support TypeScript 5.2 `using` / `await using` declaration (#15321 by @sosukesuzuki)

Support for the upcoming Explicit Resource Management feature in ECMAScript. using / await using declaration

{
   using foo = new Foo();
   await using bar = new Bar();
}

`v3.0.2`

Break after `=` of assignment if RHS is poorly breakable AwaitExpression or YieldExpression (#15204 by @seiyab)

// Input
const { section, rubric, authors, tags } = await utils.upsertCommonData(mainData);

// Prettier 3.0.1
const { section, rubric, authors, tags } = await utils.upsertCommonData(
  mainData,
);

// Prettier 3.0.2
const { section, rubric, authors, tags } =
  await utils.upsertCommonData(mainData);

Do not add trailing comma for grouped scss comments (#15217 by @auvred)

/* Input */
$foo: (
	'property': (),
	// comment 1
	// comment 2
)

/* Prettier 3.0.1 */
$foo: (
  "property": (),
  // comment 1
  // comment 2,
);

/* Prettier 3.0.2 */
$foo: (
  "property": (),
  // comment 1
  // comment 2
);

Print `declare` and `export` keywords for nested namespace (#15249 by @sosukesuzuki)

// Input
declare namespace abc1.def {}
export namespace abc2.def {}

// Prettier 3.0.1
namespace abc1.def {}
namespace abc2.def {}

// Prettier 3.0.2
declare namespace abc1.def {}
export namespace abc2.def {}

`v3.0.1`

https://blog.vuejs.org/posts/vue-3-3#generic-components

Fix cursor positioning for a special case (#14812 by @fisker)

// <|> is the cursor position

/* Input */
// All messages are represented in JSON.
// So, the prettier.py controls a subprocess which spawns "node {this_file}".
import {<|>  } from "fs"

/* Prettier 3.0.0 */
// All messages are represented in JSON.
// So, the prettier.py <|>controls a subprocess which spawns "node {this_file}".
import {} from "fs"

/* Prettier 3.0.1 */
// All messages are represented in JSON.
// So, the prettier.py controls a subprocess which spawns "node {this_file}".
import {<|>} from "fs"

Fix plugins/estree.d.ts to make it a module (#15018 by @kingyue737)

Add export {} in plugins/estree.d.ts to fix the "File is not a module" error

Add parenthesis around leading multiline comment in return statement (#15037 by @auvred)

// Input
function fn() {
  return (
    /**
     * @&#8203;type {...}
     */ expresssion
  )
}

// Prettier 3.0.0
function fn() {
  return /**
   * @&#8203;type {...}
   */ expresssion;
}

// Prettier 3.0.1
function fn() {
  return (
    /**
     * @&#8203;type {...}
     */ expresssion
  );
}

Add support for Vue "Generic Components" (#15066 by @auvred)

<!-- Input -->
<script setup lang="ts" generic="T extends Type1 & Type2 & (Type3 | Type4), U extends string | number | boolean"></script>

<!-- Prettier 3.0.0 -->
<script
  setup
  lang="ts"
  generic="T extends Type1 & Type2 & (Type3 | Type4), U extends string | number | boolean"
></script>

<!-- Prettier 3.0.1 -->
<script
  setup
  lang="ts"
  generic="
    T extends Type1 & Type2 & (Type3 | Type4),
    U extends string | number | boolean
  "
></script>

Fix comments print in `IfStatement` (#15076 by @fisker)

function a(b) {
  if (b) return 1; // comment
  else return 2;
}

/* Prettier 3.0.0 */
Error: Comment "comment" was not printed. Please report this error!

/* Prettier 3.0.1 */
function a(b) {
  if (b) return 1; // comment
  else return 2;
}

Add missing type definition for `printer.preprocess` (#15123 by @so1ve)

export interface Printer<T = any> {
  // ...
+ preprocess?:
+   | ((ast: T, options: ParserOptions<T>) => T | Promise<T>)
+   | undefined;
}

Add missing `getVisitorKeys` method type definition for `Printer` (#15125 by @auvred)

const printer: Printer = {
  print: () => [],
  getVisitorKeys(node, nonTraversableKeys) {
    return ["body"];
  },
};

Add typing to support `readonly` array properties of AST Node (#15127 by @auvred)

// Input
interface TestNode {
  readonlyArray: readonly string[];
}

declare const path: AstPath<TestNode>;

path.map(() => "", "readonlyArray");

// Prettier 3.0.0
interface TestNode {
  readonlyArray: readonly string[];
}

declare const path: AstPath<TestNode>;

path.map(() => "", "readonlyArray");
//                  ^ Argument of type '"readonlyArray"' is not assignable to parameter of type '"regularArray"'. ts(2345)

// Prettier 3.0.1
interface TestNode {
  readonlyArray: readonly string[];
}

declare const path: AstPath<TestNode>;

path.map(() => "", "readonlyArray");

Add space before unary minus followed by a function call (#15129 by @pamelalozano)

// Input
div {
  margin: - func();
}

// Prettier 3.0.0
div {
  margin: -func();
}

// Prettier 3.0.1
div {
  margin: - func();
}

`v3.0.0`

`v2.8.8`

This version is a republished version of v2.8.7.
A bad version was accidentally published and it can't be unpublished, apologies for the churn.

`v2.8.7`

Allow multiple decorators on same getter/setter (#14584 by @fisker)

// Input
class A {
  @&#8203;decorator()
  get foo () {}
  
  @&#8203;decorator()
  set foo (value) {}
}

// Prettier 2.8.6
SyntaxError: Decorators cannot be applied to multiple get/set accessors of the same name. (5:3)
  3 |   get foo () {}
  4 |   
> 5 |   @&#8203;decorator()
    |   ^^^^^^^^^^^^
  6 |   set foo (value) {}
  7 | }

// Prettier 2.8.7
class A {
  @&#8203;decorator()
  get foo() {}

  @&#8203;decorator()
  set foo(value) {}
}

`v2.8.6`

Allow decorators on private members and class expressions (#14548 by @fisker)

// Input
class A {
  @&#8203;decorator()
  #privateMethod () {}
}

// Prettier 2.8.5
SyntaxError: Decorators are not valid here. (2:3)
  1 | class A {
> 2 |   @&#8203;decorator()
    |   ^^^^^^^^^^^^
  3 |   #privateMethod () {}
  4 | }

// Prettier 2.8.6
class A {
  @&#8203;decorator()
  #privateMethod() {}
}

`v2.8.5`

Support TypeScript 5.0 (#14391 by @fisker, #13819 by @fisker, @sosukesuzuki)

TypeScript 5.0 introduces two new syntactic features:

const modifiers for type parameters
export type * declarations

Add missing parentheses for decorator (#14393 by @fisker)

// Input
class Person {
  @&#8203;(myDecoratorArray[0])
  greet() {}
}

// Prettier 2.8.4
class Person {
  @&#8203;myDecoratorArray[0]
  greet() {}
}

// Prettier 2.8.5
class Person {
  @&#8203;(myDecoratorArray[0])
  greet() {}
}

Add parentheses for `TypeofTypeAnnotation` to improve readability (#14458 by @fisker)

// Input
type A = (typeof node.children)[];

// Prettier 2.8.4
type A = typeof node.children[];

// Prettier 2.8.5
type A = (typeof node.children)[];

Support `max_line_length=off` when parsing `.editorconfig` (#14516 by @josephfrazier)

If an .editorconfig file is in your project and it sets max_line_length=off for the file you're formatting,
it will be interpreted as a printWidth of Infinity rather than being ignored
(which previously resulted in the default printWidth of 80 being applied, if not overridden by Prettier-specific configuration).

<!-- Input -->
<div className='HelloWorld' title={`You are visitor number ${ num }`} onMouseOver={onMouseOver}/>

<!-- Prettier 2.8.4 -->
<div
  className="HelloWorld"
  title={`You are visitor number ${num}`}
  onMouseOver={onMouseOver}
/>;

<!-- Prettier 2.8.5 -->
<div className="HelloWorld" title={`You are visitor number ${num}`} onMouseOver={onMouseOver} />;

`v2.8.4`

Fix leading comments in mapped types with `readonly` (#13427 by @thorn0, @sosukesuzuki)

// Input
type Type = {
  // comment
  readonly [key in Foo];
};

// Prettier 2.8.3
type Type = {
  readonly // comment
  [key in Foo];
};

// Prettier 2.8.4
type Type = {
  // comment
  readonly [key in Foo];
};

Group params in opening block statements (#14067 by @jamescdavis)

This is a follow-up to #13930 to establish wrapping consistency between opening block statements and else blocks by
grouping params in opening blocks. This causes params to break to a new line together and not be split across lines
unless the length of params exceeds the print width. This also updates the else block wrapping to behave exactly the
same as opening blocks.

{{! Input }}
{{#block param param param param param param param param param param as |blockParam|}}
  Hello
{{else block param param param param param param param param param param as |blockParam|}}
  There
{{/block}}

{{! Prettier 2.8.3 }}
{{#block
  param
  param
  param
  param
  param
  param
  param
  param
  param
  param
  as |blockParam|
}}
  Hello
{{else block param
param
param
param
param
param
param
param
param
param}}
  There
{{/block}}

{{! Prettier 2.8.4 }}
{{#block
  param param param param param param param param param param
  as |blockParam|
}}
  Hello
{{else block
  param param param param param param param param param param
  as |blockParam|
}}
  There
{{/block}}

Ignore files in `.sl/` (#14206 by @bolinfest)

In Sapling SCM, .sl/ is the folder where it stores its state, analogous to .git/ in Git. It should be ignored in Prettier like the other SCM folders.

Recognize `@satisfies` in Closure-style type casts (#14262 by @fisker)

// Input
const a = /** @&#8203;satisfies {Record<string, string>} */ ({hello: 1337});
const b = /** @&#8203;type {Record<string, string>} */ ({hello: 1337});

// Prettier 2.8.3
const a = /** @&#8203;satisfies {Record<string, string>} */ { hello: 1337 };
const b = /** @&#8203;type {Record<string, string>} */ ({ hello: 1337 });

// Prettier 2.8.4
const a = /** @&#8203;satisfies {Record<string, string>} */ ({hello: 1337});
const b = /** @&#8203;type {Record<string, string>} */ ({hello: 1337});

Fix parens in inferred function return types with `extends` (#14279 by @fisker)

// Input
type Foo<T> = T extends ((a) => a is infer R extends string) ? R : never;

// Prettier 2.8.3 (First format)
type Foo<T> = T extends (a) => a is infer R extends string ? R : never;

// Prettier 2.8.3 (Second format)
SyntaxError: '?' expected. 

// Prettier 2.8.4
type Foo<T> = T extends ((a) => a is infer R extends string) ? R : never;

`v2.8.3`

Allow self-closing tags on custom elements (#14170 by @fisker)

See Angular v15.1.0 release note for details.

// Input
<app-test/>

// Prettier 2.8.2
SyntaxError: Only void and foreign elements can be self closed "app-test" (1:1)
> 1 | <app-test/>
    | ^^^^^^^^^
  2 |

// Prettier 2.8.3
<app-test />

`v2.8.2`

Don't lowercase link references (#13155 by @DerekNonGeneric & @fisker)

<!-- Input -->
We now don't strictly follow the release notes format suggested by [Keep a Changelog].

[Keep a Changelog]: https://example.com/

<!-- Prettier 2.8.1 -->
We now don't strictly follow the release notes format suggested by [Keep a Changelog].

[keep a changelog]: https://example.com/
<!--
^^^^^^^^^^^^^^^^^^ lowercased
-->

<!-- Prettier 2.8.2 -->
<Same as input>

Preserve self-closing tags (#13691 by @dcyriller)

{{! Input }}
<div />
<div></div>
<custom-component />
<custom-component></custom-component>
<i />
<i></i>
<Component />
<Component></Component>

{{! Prettier 2.8.1 }}
<div></div>
<div></div>
<custom-component></custom-component>
<custom-component></custom-component>
<i></i>
<i></i>
<Component />
<Component />

{{! Prettier 2.8.2 }}
<div />
<div></div>
<custom-component />
<custom-component></custom-component>
<i />
<i></i>
<Component />
<Component />

Allow custom "else if"-like blocks with block params (#13930 by @jamescdavis)

#13507 added support for custom block keywords used with else, but failed to allow block params. This updates printer-glimmer to allow block params with custom "else if"-like blocks.

{{! Input }}
{{#when isAtWork as |work|}}
  Ship that
  {{work}}!
{{else when isReading as |book|}}
  You can finish
  {{book}}
  eventually...
{{else}}
  Go to bed!
{{/when}}

{{! Prettier 2.8.1 }}
{{#when isAtWork as |work|}}
  Ship that
  {{work}}!
{{else when isReading}}
  You can finish
  {{book}}
  eventually...
{{else}}
  Go to bed!
{{/when}}

{{! Prettier 2.8.2 }}
{{#when isAtWork as |work|}}
  Ship that
  {{work}}!
{{else when isReading as |book|}}
  You can finish
  {{book}}
  eventually...
{{else}}
  Go to bed!
{{/when}}

Preserve empty lines between nested SCSS maps (#13931 by @jneander)

/* Input */
$map: (
  'one': (
     'key': 'value',
  ),

  'two': (
     'key': 'value',
  ),
)

/* Prettier 2.8.1 */
$map: (
  'one': (
     'key': 'value',
  ),
  'two': (
     'key': 'value',
  ),
)

/* Prettier 2.8.2 */
$map: (
  'one': (
     'key': 'value',
  ),

  'two': (
     'key': 'value',
  ),
)

Fix missing parentheses when an expression statement starts with `let[` (#14000, #14044 by @fisker, @thorn0)

// Input
(let[0] = 2);

// Prettier 2.8.1
let[0] = 2;

// Prettier 2.8.1 (second format)
SyntaxError: Unexpected token (1:5)
> 1 | let[0] = 2;
    |     ^
  2 |

// Prettier 2.8.2
(let)[0] = 2;

Fix semicolon duplicated at the end of LESS file (#14007 by @mvorisek)

// Input
@&#8203;variable: {
  field: something;
};

// Prettier 2.8.1
@&#8203;variable: {
  field: something;
}; ;

// Prettier 2.8.2
@&#8203;variable: {
  field: something;
};

Fix no space after unary minus when followed by opening parenthesis in LESS (#14008 by @mvorisek)

// Input
.unary_minus_single {
  margin: -(@&#8203;a);
}

.unary_minus_multi {
  margin: 0 -(@&#8203;a);
}

.binary_minus {
  margin: 0 - (@&#8203;a);
}

// Prettier 2.8.1
.unary_minus_single {
  margin: - (@&#8203;a);
}

.unary_minus_multi {
  margin: 0 - (@&#8203;a);
}

.binary_minus {
  margin: 0 - (@&#8203;a);
}

// Prettier 2.8.2
.unary_minus_single {
  margin: -(@&#8203;a);
}

.unary_minus_multi {
  margin: 0 -(@&#8203;a);
}

.binary_minus {
  margin: 0 - (@&#8203;a);
}

Do not change case of property name if inside a variable declaration in LESS (#14034 by @mvorisek)

// Input
@&#8203;var: {
  preserveCase: 0;
};

// Prettier 2.8.1
@&#8203;var: {
  preservecase: 0;
};

// Prettier 2.8.2
@&#8203;var: {
  preserveCase: 0;
};

Fix formatting for auto-accessors with comments (#14038 by @fisker)

// Input
class A {
  @&#8203;dec()
  // comment
  accessor b;
}

// Prettier 2.8.1
class A {
  @&#8203;dec()
  accessor // comment
  b;
}

// Prettier 2.8.1 (second format)
class A {
  @&#8203;dec()
  accessor; // comment
  b;
}

// Prettier 2.8.2
class A {
  @&#8203;dec()
  // comment
  accessor b;
}

Add parentheses for TSTypeQuery to improve readability (#14042 by @onishi-kohei)

// Input
a as (typeof node.children)[number]
a as (typeof node.children)[]
a as ((typeof node.children)[number])[]

// Prettier 2.8.1
a as typeof node.children[number];
a as typeof node.children[];
a as typeof node.children[number][];

// Prettier 2.8.2
a as (typeof node.children)[number];
a as (typeof node.children)[];
a as (typeof node.children)[number][];

Fix displacing of comments in default switch case (#14047 by @thorn0)

It was a regression in Prettier 2.6.0.

// Input
switch (state) {
  default:
    result = state; // no change
    break;
}

// Prettier 2.8.1
switch (state) {
  default: // no change
    result = state;
    break;
}

// Prettier 2.8.2
switch (state) {
  default:
    result = state; // no change
    break;
}

Support type annotations on auto accessors via `babel-ts` (#14049 by @sosukesuzuki)

The bug that @babel/parser cannot parse auto accessors with type annotations has been fixed. So we now support it via babel-ts parser.

class Foo {
  accessor prop: number;
}

Fix formatting of empty type parameters (#14073 by @fisker)

// Input
const foo: bar</* comment */> = () => baz;

// Prettier 2.8.1
Error: Comment "comment" was not printed. Please report this error!

// Prettier 2.8.2
const foo: bar</* comment */> = () => baz;

Add parentheses to head of `ExpressionStatement` instead of the whole statement (#14077 by @fisker)

// Input
({}).toString.call(foo) === "[object Array]"
  ? foo.forEach(iterateArray)
  : iterateObject(foo);

// Prettier 2.8.1
({}.toString.call(foo) === "[object Array]"
  ? foo.forEach(iterateArray)
  : iterateObject(foo));

// Prettier 2.8.2
({}).toString.call(foo.forEach) === "[object Array]"
  ? foo.forEach(iterateArray)
  : iterateObject(foo);

Fix comments after directive (#14081 by @fisker)

// Input
"use strict" /* comment */;

// Prettier 2.8.1 (with other js parsers except `babel`)
Error: Comment "comment" was not printed. Please report this error!

// Prettier 2.8.2
<Same as input>

Fix formatting for comments inside JSX attribute (#14082 by @fisker)

// Input
function MyFunctionComponent() {
  <button label=/*old*/"new">button</button>
}

// Prettier 2.8.1
Error: Comment "old" was not printed. Please report this error!

// Prettier 2.8.2
function MyFunctionComponent() {
  <button label=/*old*/ "new">button</button>;
}

Quote numeric keys for json-stringify parser (#14083 by @fisker)

// Input
{0: 'value'}

// Prettier 2.8.1
{
  0: "value"
}

// Prettier 2.8.2
{
  "0": "value"
}

Fix removing commas from function arguments in maps (#14089 by @sosukesuzuki)

/* Input */
$foo: map-fn(
  (
    "#{prop}": inner-fn($first, $second),
  )
);

/* Prettier 2.8.1 */
$foo: map-fn(("#{prop}": inner-fn($first $second)));

/* Prettier 2.8.2 */
$foo: map-fn(
  (
    "#{prop}": inner-fn($first, $second),
  )
);

Do not insert space in LESS property access (#14103 by @fisker)

// Input
a {
  color: @&#8203;colors[@&#8203;white];
}

// Prettier 2.8.1
a {
  color: @&#8203;colors[ @&#8203;white];
}

// Prettier 2.8.2
<Same as input>

`v2.8.1`

Fix SCSS map in arguments (#9184 by @agamkrbit)

// Input
$display-breakpoints: map-deep-merge(
  (
    "print-only": "only print",
    "screen-only": "only screen",
    "xs-only": "only screen and (max-width: #{map-get($grid-breakpoints, "sm")-1})",
  ),
  $display-breakpoints
);

// Prettier 2.8.0
$display-breakpoints: map-deep-merge(
  (
    "print-only": "only print",
    "screen-only": "only screen",
    "xs-only": "only screen and (max-width: #{map-get($grid-breakpoints, " sm
      ")-1})",
  ),
  $display-breakpoints
);

// Prettier 2.8.1
$display-breakpoints: map-deep-merge(
  (
    "print-only": "only print",
    "screen-only": "only screen",
    "xs-only": "only screen and (max-width: #{map-get($grid-breakpoints, "sm")-1})",
  ),
  $display-breakpoints
);

Support auto accessors syntax (#13919 by @sosukesuzuki)

Support for Auto Accessors Syntax landed in TypeScript 4.9.

(Doesn't work well with babel-ts parser)

class Foo {
  accessor foo: number = 3;
}

`v2.8.0`

`v2.7.1`

Keep useful empty lines in description (#13013 by @chimurai)

`v2.7.0`