From 5aea916df5fc4b7fedf434a61935454ef289eb36 Mon Sep 17 00:00:00 2001
From: Marco Roth <marco.roth@intergga.ch>
Date: Mon, 25 Aug 2025 18:12:53 +0200
Subject: [PATCH 1/2] Linter: Allow self-closing tags in SVG
 (`html-no-self-closing`)

---
 .../linter/src/rules/html-no-self-closing.ts  | 21 +++---
 .../test/rules/html-no-self-closing.test.ts   | 70 ++++++++++++++-----
 2 files changed, 67 insertions(+), 24 deletions(-)

diff --git a/javascript/packages/linter/src/rules/html-no-self-closing.ts b/javascript/packages/linter/src/rules/html-no-self-closing.ts
index b6fffce40..410f4d6d0 100644
--- a/javascript/packages/linter/src/rules/html-no-self-closing.ts
+++ b/javascript/packages/linter/src/rules/html-no-self-closing.ts
@@ -1,25 +1,30 @@
 import { ParserRule } from "../types.js"
-import { BaseRuleVisitor, getTagName, isVoidElement } from "./rule-utils.js"
+import { BaseRuleVisitor, isVoidElement } from "./rule-utils.js"
+import { getTagName } from "@herb-tools/core"
 
 import type { LintContext, LintOffense } from "../types.js"
-import type { HTMLOpenTagNode, ParseResult } from "@herb-tools/core"
+import type { HTMLOpenTagNode, HTMLElementNode, ParseResult } from "@herb-tools/core"
 
 class NoSelfClosingVisitor extends BaseRuleVisitor {
+  visitHTMLElementNode(node: HTMLElementNode): void {
+    if (getTagName(node) === "svg") {
+      this.visit(node.open_tag)
+    } else {
+      this.visitChildNodes(node)
+    }
+  }
+
   visitHTMLOpenTagNode(node: HTMLOpenTagNode): void {
     if (node.tag_closing?.value === "/>") {
       const tagName = getTagName(node)
-
-      const shouldBeVoid = tagName ? isVoidElement(tagName) : false
-      const instead = shouldBeVoid ? `Use \`<${tagName}>\` instead.` : `Use \`<${tagName}></${tagName}>\` instead.`
+      const instead = isVoidElement(tagName) ? `<${tagName}>` : `<${tagName}></${tagName}>`
 
       this.addOffense(
-        `Self-closing syntax \`<${tagName} />\` is not allowed in HTML. ${instead}`,
+        `Use \`${instead}\` instead of self-closing \`<${tagName} />\` for HTML compatibility.`,
         node.location,
         "error"
       )
     }
-
-    super.visitHTMLOpenTagNode(node)
   }
 }
 
diff --git a/javascript/packages/linter/test/rules/html-no-self-closing.test.ts b/javascript/packages/linter/test/rules/html-no-self-closing.test.ts
index 8f39af888..c0d648cb5 100644
--- a/javascript/packages/linter/test/rules/html-no-self-closing.test.ts
+++ b/javascript/packages/linter/test/rules/html-no-self-closing.test.ts
@@ -32,20 +32,22 @@ describe("html-no-self-closing", () => {
       <span />
       <section />
       <custom-element />
+      <svg />
     `;
     const linter = new Linter(Herb, [HTMLNoSelfClosingRule]);
     const lintResult = linter.lint(html);
 
-    expect(lintResult.errors).toBe(4);
-    expect(lintResult.offenses).toHaveLength(4);
+    expect(lintResult.errors).toBe(5);
+    expect(lintResult.offenses).toHaveLength(5);
 
     expect(lintResult.offenses[0].rule).toBe("html-no-self-closing");
     expect(lintResult.offenses[0].severity).toBe("error");
 
-    expect(lintResult.offenses[0].message).toBe('Self-closing syntax `<div />` is not allowed in HTML. Use `<div></div>` instead.')
-    expect(lintResult.offenses[1].message).toBe('Self-closing syntax `<span />` is not allowed in HTML. Use `<span></span>` instead.')
-    expect(lintResult.offenses[2].message).toBe('Self-closing syntax `<section />` is not allowed in HTML. Use `<section></section>` instead.')
-    expect(lintResult.offenses[3].message).toBe('Self-closing syntax `<custom-element />` is not allowed in HTML. Use `<custom-element></custom-element>` instead.')
+    expect(lintResult.offenses[0].message).toBe('Use `<div></div>` instead of self-closing `<div />` for HTML compatibility.')
+    expect(lintResult.offenses[1].message).toBe('Use `<span></span>` instead of self-closing `<span />` for HTML compatibility.')
+    expect(lintResult.offenses[2].message).toBe('Use `<section></section>` instead of self-closing `<section />` for HTML compatibility.')
+    expect(lintResult.offenses[3].message).toBe('Use `<custom-element></custom-element>` instead of self-closing `<custom-element />` for HTML compatibility.')
+    expect(lintResult.offenses[4].message).toBe('Use `<svg></svg>` instead of self-closing `<svg />` for HTML compatibility.')
   });
 
   test("fails for self-closing void elements", () => {
@@ -64,10 +66,10 @@ describe("html-no-self-closing", () => {
     expect(lintResult.offenses[0].rule).toBe("html-no-self-closing");
     expect(lintResult.offenses[0].severity).toBe("error");
 
-    expect(lintResult.offenses[0].message).toBe('Self-closing syntax `<img />` is not allowed in HTML. Use `<img>` instead.')
-    expect(lintResult.offenses[1].message).toBe('Self-closing syntax `<input />` is not allowed in HTML. Use `<input>` instead.')
-    expect(lintResult.offenses[2].message).toBe('Self-closing syntax `<br />` is not allowed in HTML. Use `<br>` instead.')
-    expect(lintResult.offenses[3].message).toBe('Self-closing syntax `<hr />` is not allowed in HTML. Use `<hr>` instead.')
+    expect(lintResult.offenses[0].message).toBe('Use `<img>` instead of self-closing `<img />` for HTML compatibility.')
+    expect(lintResult.offenses[1].message).toBe('Use `<input>` instead of self-closing `<input />` for HTML compatibility.')
+    expect(lintResult.offenses[2].message).toBe('Use `<br>` instead of self-closing `<br />` for HTML compatibility.')
+    expect(lintResult.offenses[3].message).toBe('Use `<hr>` instead of self-closing `<hr />` for HTML compatibility.')
   });
 
   test("passes for mixed correct and incorrect tags", () => {
@@ -83,8 +85,8 @@ describe("html-no-self-closing", () => {
     expect(lintResult.errors).toBe(2);
     expect(lintResult.offenses).toHaveLength(2);
 
-    expect(lintResult.offenses[0].message).toBe('Self-closing syntax `<span />` is not allowed in HTML. Use `<span></span>` instead.')
-    expect(lintResult.offenses[1].message).toBe('Self-closing syntax `<input />` is not allowed in HTML. Use `<input>` instead.')
+    expect(lintResult.offenses[0].message).toBe('Use `<span></span>` instead of self-closing `<span />` for HTML compatibility.')
+    expect(lintResult.offenses[1].message).toBe('Use `<input>` instead of self-closing `<input />` for HTML compatibility.')
   });
 
   test("passes for nested non-self-closing tags", () => {
@@ -114,8 +116,8 @@ describe("html-no-self-closing", () => {
     expect(lintResult.errors).toBe(2);
     expect(lintResult.offenses).toHaveLength(2);
 
-    expect(lintResult.offenses[0].message).toBe('Self-closing syntax `<span />` is not allowed in HTML. Use `<span></span>` instead.')
-    expect(lintResult.offenses[1].message).toBe('Self-closing syntax `<section />` is not allowed in HTML. Use `<section></section>` instead.')
+    expect(lintResult.offenses[0].message).toBe('Use `<span></span>` instead of self-closing `<span />` for HTML compatibility.')
+    expect(lintResult.offenses[1].message).toBe('Use `<section></section>` instead of self-closing `<section />` for HTML compatibility.')
   });
 
   test("passes for custom elements without self-closing", () => {
@@ -141,8 +143,8 @@ describe("html-no-self-closing", () => {
     expect(lintResult.errors).toBe(2);
     expect(lintResult.offenses).toHaveLength(2);
 
-    expect(lintResult.offenses[0].message).toBe('Self-closing syntax `<custom-element />` is not allowed in HTML. Use `<custom-element></custom-element>` instead.')
-    expect(lintResult.offenses[1].message).toBe('Self-closing syntax `<another-custom />` is not allowed in HTML. Use `<another-custom></another-custom>` instead.')
+    expect(lintResult.offenses[0].message).toBe('Use `<custom-element></custom-element>` instead of self-closing `<custom-element />` for HTML compatibility.')
+    expect(lintResult.offenses[1].message).toBe('Use `<another-custom></another-custom>` instead of self-closing `<another-custom />` for HTML compatibility.')
   });
 
   test("passes for void elements without self-closing", () => {
@@ -158,4 +160,40 @@ describe("html-no-self-closing", () => {
     expect(lintResult.errors).toBe(0);
     expect(lintResult.offenses).toHaveLength(0);
   });
+
+  test("passes for self-closing elements inside SVG", () => {
+    const html = `
+      <div class="flex items-center text-xs text-gray-500 mt-1">
+        <svg class="w-3 h-3 mr-1 fill-gray-400" viewBox="0 0 24 24">
+          <path d="M12 2C8.13 2 5 5.13 5 9c0 5.25 7 13 7 13s7-7.75 7-13c0-3.87-3.13-7-7-7zm0 9.5c-1.38 0-2.5-1.12-2.5-2.5s1.12-2.5 2.5-2.5 2.5 1.12 2.5 2.5-1.12 2.5-2.5 2.5z" />
+          <circle cx="12" cy="12" r="10" />
+          <rect x="0" y="0" width="24" height="24" />
+        </svg>
+      </div>
+    `;
+    const linter = new Linter(Herb, [HTMLNoSelfClosingRule]);
+    const lintResult = linter.lint(html);
+
+    expect(lintResult.errors).toBe(0);
+    expect(lintResult.offenses).toHaveLength(0);
+  });
+
+  test("fails for self-closing elements outside SVG but passes inside SVG", () => {
+    const html = `
+      <div />
+      <svg class="w-3 h-3" viewBox="0 0 24 24">
+        <path d="M12 2C8.13 2 5 5.13 5 9c0 5.25 7 13 7 13s7-7.75 7-13c0-3.87-3.13-7-7-7zm0 9.5c-1.38 0-2.5-1.12-2.5-2.5s1.12-2.5 2.5-2.5 2.5 1.12 2.5 2.5-1.12 2.5-2.5 2.5z" />
+        <circle cx="12" cy="12" r="10" />
+      </svg>
+      <span />
+    `;
+    const linter = new Linter(Herb, [HTMLNoSelfClosingRule]);
+    const lintResult = linter.lint(html);
+
+    expect(lintResult.errors).toBe(2);
+    expect(lintResult.offenses).toHaveLength(2);
+
+    expect(lintResult.offenses[0].message).toBe('Use `<div></div>` instead of self-closing `<div />` for HTML compatibility.');
+    expect(lintResult.offenses[1].message).toBe('Use `<span></span>` instead of self-closing `<span />` for HTML compatibility.');
+  });
 });

From d7f3db177fb6f300546d80118a508f6c65e57ee3 Mon Sep 17 00:00:00 2001
From: Marco Roth <marco.roth@intergga.ch>
Date: Mon, 25 Aug 2025 18:24:24 +0200
Subject: [PATCH 2/2] Update snapshot

---
 javascript/packages/linter/test/__snapshots__/cli.test.ts.snap | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/javascript/packages/linter/test/__snapshots__/cli.test.ts.snap b/javascript/packages/linter/test/__snapshots__/cli.test.ts.snap
index d65715633..870d50e49 100644
--- a/javascript/packages/linter/test/__snapshots__/cli.test.ts.snap
+++ b/javascript/packages/linter/test/__snapshots__/cli.test.ts.snap
@@ -151,7 +151,7 @@ test/fixtures/multiple-rule-offenses.html.erb:10:4
 
 ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯  [10/11] ⎯⎯⎯⎯
 
-[error] Self-closing syntax \`<img />\` is not allowed in HTML. Use \`<img>\` instead. (html-no-self-closing)
+[error] Use \`<img>\` instead of self-closing \`<img />\` for HTML compatibility. (html-no-self-closing)
 
 test/fixtures/multiple-rule-offenses.html.erb:4:2