chore: update lint rules for comments

web/eslint-plugins/__tests__/comment-format.test.ts

@@ -1,8 +1,12 @@
 // Tests for the conventions/comment-format rule
 // (web/eslint-plugins/conventions/comment-format.js).
 //
-// Pure AST check (comment nodes + line counts), standard RuleTester.
+// Pure AST check (comment nodes + line counts), standard RuleTester. The
+// svelte pass pins the two comment kinds the token stream never sees: template
+// `<!-- -->` comments (AST nodes) and CSS in `<style>` (a postcss AST); both
+// need a svelte parser to exist at all.
 import { RuleTester } from "eslint";
+import svelteParser from "svelte-eslint-parser";
 import tseslint from "typescript-eslint";
 import { describe, it } from "vitest";
 import commentFormat from "../conventions/comment-format.js";
@@ -17,6 +21,13 @@ const tester = new RuleTester({
 	},
 });
 
+const svelteTester = new RuleTester({
+	languageOptions: {
+		parser: svelteParser,
+		parserOptions: { parser: tseslint.parser },
+	},
+});
+
 const longBlock = [
 	"// one",
 	"// two",
@@ -96,3 +107,101 @@ tester.run("comment-format", asRuleModule(commentFormat), {
 		},
 	],
 });
+
+svelteTester.run("comment-format (svelte)", asRuleModule(commentFormat), {
+	valid: [
+		{
+			code: "<!-- why -->\n<main>Hello</main>",
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+		},
+		{
+			// A template comment at the cap is fine, same as in a .ts file.
+			code: "<!--\na\nb\nc\n-->\n<main>Hello</main>",
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+		},
+		{
+			// Script and template comments are separate blocks, not one run.
+			code: '<!-- why -->\n<main>Hello</main>\n<script lang="ts">\n// why\n</script>',
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+		},
+		{
+			// A CSS comment at the cap is fine, same as a script comment.
+			code: "<style>\n/*\na\nb\nc\n*/\n.x {\n\tcolor: red;\n}\n</style>",
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+		},
+		{
+			// Script and <style> comments live in different ASTs: no run across,
+			// so 2 + 5 lines pass where a merged block of 7 would not.
+			code: '<script lang="ts">\n// one\n// two\n</script>\n<style>\n/*\na\nb\nc\n*/\n.x {\n\tcolor: red;\n}\n</style>',
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+		},
+	],
+	invalid: [
+		{
+			// The template comment the ts pass could never see, over the cap.
+			code: "<!--\na\nb\nc\nd\n-->\n<main>Hello</main>",
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+			errors: [{ messageId: "blockTooLong" }],
+		},
+		{
+			// <style> is a postcss AST, so its comments are invisible to
+			// getAllComments(); the loc must still point at the real line.
+			code: "<style>\n/*\na\nb\nc\nd\n*/\n.x {\n\tcolor: red;\n}\n</style>",
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+			errors: [{ messageId: "blockTooLong", line: 2 }],
+		},
+		{
+			// A comment nested in markup is collected too (not Program.body).
+			code: "<div>\n\t<!--\n\ta\n\tb\n\tc\n\td\n\t-->\n</div>",
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+			errors: [{ messageId: "blockTooLong" }],
+		},
+		{
+			// Template comment lines count toward density: 2 of 4 non-blank.
+			code: "<!-- a -->\n<!-- b -->\n<p>x</p>\n<p>y</p>",
+			filename: "Component.svelte",
+			options: [{ maxBlockLines: 5, maxRatio: 0.4 }],
+			errors: [{ messageId: "tooDense" }],
+		},
+		{
+			// Script and template comments share one density budget.
+			code: '<!-- a -->\n<script lang="ts">\n// b\n</script>\n<p>c</p>',
+			filename: "Component.svelte",
+			options: [{ maxBlockLines: 5, maxRatio: 0.3 }],
+			errors: [{ messageId: "tooDense" }],
+		},
+		{
+			// CSS lines count toward density too: 2 of 8 non-blank. Consecutive
+			// CSS comments stay separate blocks (each one line, under the cap).
+			code: "<p>x</p>\n<style>\n/* a */\n/* b */\n.x {\n\tcolor: red;\n}\n</style>",
+			filename: "Component.svelte",
+			options: [{ maxBlockLines: 5, maxRatio: 0.2 }],
+			errors: [{ messageId: "tooDense" }],
+		},
+		{
+			// All three kinds over the cap: one report per block, by position.
+			code: "<!--\na\nb\nc\nd\ne\n-->\n<style>\n/*\nx\ny\nz\nw\nv\n*/\n.x {\n\tcolor: red;\n}\n</style>",
+			filename: "Component.svelte",
+			options: [{ maxRatio: 1 }],
+			errors: [
+				{ messageId: "blockTooLong", line: 1 },
+				{ messageId: "blockTooLong", line: 9 },
+			],
+		},
+		{
+			// Both violations in one file produce two reports.
+			code: "<!--\na\nb\nc\nd\n-->\n<p>x</p>",
+			filename: "Component.svelte",
+			options: [{ maxBlockLines: 5, maxRatio: 0.5 }],
+			errors: [{ messageId: "blockTooLong" }, { messageId: "tooDense" }],
+		},
+	],
+});