feat!: updated the html-self-closing rule to follow Svelte5 (#982)

Author: baseballyama

.changeset/soft-bears-hear.md

@@ -0,0 +1,5 @@
+---
+'eslint-plugin-svelte': major
+---
+
+feat!: Updated the `html-self-closing` rule to follow Svelte5

docs/rules/html-self-closing.md

@@ -14,10 +14,10 @@ since: 'v2.5.0'
 
 ## :book: Rule Details
 
-You can choose either two styles for elements without content
+You can choose either two styles for elements without content.
 
-- always: `<div />`
-- never: `<div></div>`
+- always: `<SomeComponent />`
+- never: `<SomeComponent></SomeComponent>`
 
 <!-- prettier-ignore-start -->
 <!--eslint-skip-->
@@ -28,18 +28,21 @@ You can choose either two styles for elements without content
 </script>
 
 <!-- ✓ GOOD -->
-<div />
 <p>Hello</p>
-<div><div /></div>
+<div></div>
 <img />
 <svelte:head />
+<svg><path /></svg>
+<math><msup></msup></math>
+<SomeComponent />
 
 <!-- ✗ BAD -->
-<div></div>
-<p> </p>
-<div><div></div></div>
-<img>
+<div />
+<div><div /></div>
 <svelte:body></svelte:body>
+<svg><path></path></svg>
+<math><msup /></math>
+<SomeComponent></SomeComponent>
 ```
 
 <!-- prettier-ignore-end -->
@@ -52,7 +55,7 @@ presets:
 {
   "svelte/html-self-closing": [
     "error",
-    "all" // or "html" or "none"
+    "default" // or "all" or "html" or "none"
   ]
 }
 ```
@@ -65,8 +68,9 @@ config object:
     "error",
     {
       "void": "always", // or "never" or "ignore"
-      "normal": "always", // or "never" or "ignore"
-      "foreign": "always", // or "never" or "ignore"
+      "normal": "never", // or "always" or "ignore"
+      "svg": "always", // or "never" or "ignore"
+      "never": "never", // or "always" or "ignore"
       "component": "always", // or "never" or "ignore"
       "svelte": "always" // or "never" or "ignore"
     }
@@ -76,23 +80,33 @@ config object:
 
 presets:
 
-- `all` - all elements should be self closing (unless they have children)
-- `html` - html-compliant - only void elements and svelte special elements should be self closing
-- `none` - no elements should be self closing
+- `default` - MathML and non-void HTML elements should have a closing tag; otherwise, they should be self-closing.
+- `all` - all elements should be self-closing (unless they have children)
+- `html` - html-compliant - only void elements and svelte special elements should be self-closing
+- `none` - no elements should be self-closing
+
+::: warning Note
+We recommend selecting `default` as the preset. Choosing any other option may result in settings that are inconsistent with the compiler when using Svelte5.
+:::
 
 config object:
 
 - `void` (`"always"` in default preset)... Style of HTML void elements
-- `foreign` (`"always"` in default preset)... Style of foreign elements (SVG and MathML)
+- `normal` (`"never"` in default preset)... Style of other elements
+- `svg` (`"always"` in default preset)... Style of SVG
+- `math` (`never` in default preset)... Style of MathML
 - `component` (`"always"` in default preset)... Style of svelte components
 - `svelte` (`"always"` in default preset)... Style of svelte special elements (`<svelte:head>`, `<svelte:self>`)
-- `normal` (`"always"` in default preset)... Style of other elements
 
-Every config oject option can be set to
+::: warning
+`foreign` is removed in `eslint-plugin-svelte` v3.
+:::
+
+Every config object option can be set to
 
-- "always" (`<div />`)
-- "never" (`<div></div>`)
-- "ignore" (either `<div />` or `<div></div>`)
+- "always" (`<SomeComponent />`)
+- "never" (`<SomeComponent></SomeComponent>`)
+- "ignore" (either `<SomeComponent />` or `<SomeComponent></SomeComponent>`)
 
 ## :rocket: Version
 

packages/eslint-plugin-svelte/src/rule-types.ts

@@ -419,7 +419,8 @@ type SvelteHtmlQuotes = []|[{
 type SvelteHtmlSelfClosing = []|[({
   void?: ("never" | "always" | "ignore")
   normal?: ("never" | "always" | "ignore")
-  foreign?: ("never" | "always" | "ignore")
+  svg?: ("never" | "always" | "ignore")
+  math?: ("never" | "always" | "ignore")
   component?: ("never" | "always" | "ignore")
   svelte?: ("never" | "always" | "ignore")
 } | ("all" | "html" | "none"))]

packages/eslint-plugin-svelte/src/rules/html-self-closing.ts

@@ -1,17 +1,23 @@
 import type { AST } from 'svelte-eslint-parser';
 import { createRule } from '../utils/index.js';
-import { getNodeName, isVoidHtmlElement, isForeignElement } from '../utils/ast-utils.js';
+import {
+	getNodeName,
+	isVoidHtmlElement,
+	isSvgElement,
+	isMathMLElement
+} from '../utils/ast-utils.js';
 import { getSourceCode } from '../utils/compat.js';
 
 const TYPE_MESSAGES = {
 	normal: 'HTML elements',
 	void: 'HTML void elements',
-	foreign: 'foreign (SVG or MathML) elements',
+	svg: 'SVG elements',
+	math: 'MathML elements',
 	component: 'Svelte custom components',
 	svelte: 'Svelte special elements'
 };
 
-type ElementTypes = 'normal' | 'void' | 'foreign' | 'component' | 'svelte';
+type ElementTypes = 'normal' | 'void' | 'svg' | 'math' | 'component' | 'svelte';
 
 export default createRule('html-self-closing', {
 	meta: {
@@ -38,7 +44,10 @@ export default createRule('html-self-closing', {
 							normal: {
 								enum: ['never', 'always', 'ignore']
 							},
-							foreign: {
+							svg: {
+								enum: ['never', 'always', 'ignore']
+							},
+							math: {
 								enum: ['never', 'always', 'ignore']
 							},
 							component: {
@@ -58,34 +67,49 @@ export default createRule('html-self-closing', {
 		]
 	},
 	create(context) {
+		// default
 		let options = {
 			void: 'always',
-			normal: 'always',
-			foreign: 'always',
+			normal: 'never',
+			svg: 'always',
+			math: 'never',
 			component: 'always',
 			svelte: 'always'
 		};
 
 		const option = context.options?.[0];
 		switch (option) {
-			case 'none':
+			case 'all':
 				options = {
-					void: 'never',
-					normal: 'never',
-					foreign: 'never',
-					component: 'never',
-					svelte: 'never'
+					void: 'always',
+					normal: 'always',
+					svg: 'always',
+					math: 'always',
+					component: 'always',
+					svelte: 'always'
 				};
 				break;
 			case 'html':
 				options = {
 					void: 'always',
 					normal: 'never',
-					foreign: 'always',
+					svg: 'always',
+					math: 'never',
 					component: 'never',
 					svelte: 'always'
 				};
 				break;
+			case 'none':
+				options = {
+					void: 'never',
+					normal: 'never',
+					svg: 'never',
+					math: 'never',
+					component: 'never',
+					svelte: 'never'
+				};
+				break;
+
 			default:
 				if (typeof option !== 'object' || option === null) break;
 
@@ -108,7 +132,8 @@ export default createRule('html-self-closing', {
 			if (node.kind === 'component') return 'component';
 			if (node.kind === 'special') return 'svelte';
 			if (isVoidHtmlElement(node)) return 'void';
-			if (isForeignElement(node)) return 'foreign';
+			if (isSvgElement(node)) return 'svg';
+			if (isMathMLElement(node)) return 'math';
 			return 'normal';
 		}
 

packages/eslint-plugin-svelte/src/utils/ast-utils.ts

@@ -567,6 +567,14 @@ export function isForeignElement(node: SvAST.SvelteElement): boolean {
 	return svgElements.includes(getNodeName(node)) || mathmlElements.includes(getNodeName(node));
 }
 
+export function isSvgElement(node: SvAST.SvelteElement): boolean {
+	return svgElements.includes(getNodeName(node));
+}
+
+export function isMathMLElement(node: SvAST.SvelteElement): boolean {
+	return mathmlElements.includes(getNodeName(node));
+}
+
 /** Checks whether the given identifier node is used as an expression. */
 export function isExpressionIdentifier(node: TSESTree.Identifier): boolean {
 	const parent = node.parent;

packages/eslint-plugin-svelte/tests/fixtures/rules/html-self-closing/invalid/foreign-never/svelte-never-errors.yaml

@@ -1,7 +1,7 @@
 {
 	"options": [
 		{
-			"foreign": "never"
+			"math": "never"
 		}
 	]
 }

packages/eslint-plugin-svelte/tests/fixtures/rules/html-self-closing/invalid/foreign-never/_config.json renamed to packages/eslint-plugin-svelte/tests/fixtures/rules/html-self-closing/invalid/math-never/_config.json

@@ -0,0 +1,4 @@
+- message: Disallow self-closing on MathML elements.
+  line: 3
+  column: 13
+  suggestions: null

packages/eslint-plugin-svelte/tests/fixtures/rules/html-self-closing/invalid/math-never/svelte-never-errors.yaml

@@ -1,3 +1,3 @@
 <!-- prettier-ignore -->
-<svg><path ></path></svg>
+<svg><path /></svg>
 <math><msup ></msup></math>