diff --git a/internal/test-utils/content/code-comments.md b/internal/test-utils/content/code-comments.md
new file mode 100644
index 00000000..166edd57
--- /dev/null
+++ b/internal/test-utils/content/code-comments.md
@@ -0,0 +1,191 @@
+# Code comments test document
+
+This document contains code blocks in many popular languages. Each code block includes comments in the language's syntax, and some also include contents that might be misinterpreted as a comment by a naive parser.
+
+The contents of actual comments are wrapped between pairs of `!!!` sequences (e.g. `!!! this is a comment !!!`), which allows tests to verify that the comments are recognized correctly from start to end.
+
+The contents of expressions that might be misinterpreted as comments contain a `XXX` sequence that can be used by tests to verify that the parser does not treat them as comments.
+
+## JavaScript
+
+```js
+// !!! separate line !!!
+console.log('Hello, world!'); // !!! end of line 1 !!!
+/* !!! multi-line comment on its own single line !!! */
+console.log('Hello, world!'); /* !!! multi-line comment starting
+at the end of a line and spanning multiple lines
+after it !!! */ let a = 1; // !!! end of line 2 !!!
+/* !!! another multi-line comment
+// this is not a separate comment
+end of multi-line comment !!! */
+let b = `Template strings can span
+// multiple lines and contents inside can XXX
+look like comments /* although they are not XXX */,
+and they can contain ${/* !!! real comments inside
+expressions !!! */
+// !!! even multiple ones !!!
+'nested /* strings XXX */'}`;
+```
+
+## TypeScript
+
+```ts
+function test(x: number): void {
+  // !!! separate line !!!
+  console.log('Hello, world!'); // !!! end of line 1 !!!
+  /* !!! multi-line comment on its own single line !!! */
+  console.log('Hello, world!'); /* !!! multi-line comment starting
+  at the end of a line and spanning multiple lines
+  after it !!! */ let a = 1 as number; // !!! end of line 2 !!!
+  /* !!! another multi-line comment
+  // this is not a separate comment
+  end of multi-line comment !!! */
+  let b: string = `Template strings can span
+  // multiple lines and contents inside can XXX
+  look like comments /* although they are not XXX */,
+  and they can contain ${/* !!! real comments inside
+  expressions !!! */
+  // !!! even multiple ones !!!
+  'nested /* strings XXX */' + x}`;
+}
+```
+
+## HTML
+
+```html
+<!-- !!! separate line !!! -->
+<p>Hello, world! XXX
+XXX
+</p> <!-- !!! end of line 1 !!! -->
+<p>Hello, world!</p> <!-- !!! multi-line comment starting
+at the end of a line and spanning multiple lines
+after it !!! --> <span>Some text</span> <!-- !!! end of line 2 !!! -->
+<!-- !!! another multi-line comment
+<!-- this is not a separate comment, HTML does not support nesting comments
+end of multi-line comment !!! -->
+<span>Some text</span>
+<script>
+  // !!! JS comment in nested <script> element !!!
+  console.log('Hello, /* world XXX */!'); /* !!! multi-line comment starting
+  at the end of a line and spanning multiple lines
+  after it !!! */ let a = 1; // !!! end of line 2 !!!
+</script>
+<style>
+  /* !!! CSS comment in nested <style> element !!! */
+</style>
+```
+
+## CSS
+
+```css
+/* !!! separate line !!! */
+body {
+  color: black; /* !!! end of line 1 !!! */
+  font-size: 2rem; /* !!! multi-line comment starting
+  at the end of a line and spanning multiple lines
+  after it !!! */ background-color: white; /* !!! end of line 2 !!! */
+}
+/* !!! another multi-line comment
+/* this is not a separate comment, CSS does not support nesting comments
+end of multi-line comment !!! */
+div {
+  /* !!! beginning of line !!! */color: black;
+  content: "/* this is not a comment XXX */";
+  content: 'and /* this neither XXX */';
+}
+```
+
+## MD
+
+````md
+<!-- !!! separate line !!! -->
+# Hello, world! <!-- !!! end of line 1 !!! -->
+Some text <!-- !!! multi-line comment starting
+at the end of a line and spanning multiple lines
+after it !!! --> <span>Some text</span> <!-- !!! end of line 2 !!! -->
+// this is not a comment XXX
+```js
+// !!! comment in nested JS code !!!
+return `
+<!-- this is not a comment XXX -->
+`
+```
+<!-- !!! back in md !!! -->
+````
+
+## MDX
+
+````mdx
+{/* !!! separate line !!! */}
+# Hello, world! {/* !!! end of line 1 !!! */}
+Some text {/* !!! multi-line comment starting
+at the end of a line and spanning multiple lines
+after it !!! */} <span>Some text</span> {/* !!! end of line 2 !!! */}
+// this is not a comment XXX
+```js
+// !!! comment in nested JS code !!!
+return `
+{/* this is not a comment XXX */}
+`
+```
+{/* !!! back in mdx !!! */}
+````
+
+## YAML
+
+```yml
+# !!! separate line !!!
+key: value # !!! end of value !!!
+list: # !!! end of list start !!!
+  - item1 # !!! end of list item !!!
+string: "This is a string # XXX and this is not a comment" # !!! end of string !!!
+literal:   |
+  This is a literal block scalar that can contain
+  various "quotes" like 'this',
+  and even blank lines: # XXX not a comment
+
+  # Newlines are kept as-is. XXX
+# !!! end of block scalar 1 !!!
+folded:  >
+  This is a folded block scalar that can contain
+  various "quotes" like 'this',
+  and even blank lines: # XXX not a comment
+  
+  # also not a comment XXX
+  - even
+  - things: that look like lists,
+    some extra indentation,
+  it's all just a long multiline string.
+# !!! end of block scalar 2 !!!
+a: |2
+  # XXX with indentation indicator
+b:  |-2
+  # XXX with indentation indicator and no end newline
+c: |+2
+  # XXX with indentation indicator and all end newlines
+d:   >2
+  # XXX with indentation indicator
+e: >-2
+  # XXX with indentation indicator and no end newline
+f:  >+2
+  # XXX with indentation indicator and all end newlines
+# !!! end of all block scalars !!!
+```
+
+# Todos
+
+- JSX/TSX
+- Python
+- Ruby
+- Shell
+- SQL
+- JSON
+- TOML
+- XML
+- Java
+- C#
+- C++
+- C
+- Swift
+- Kotlin
+- Rust
diff --git a/packages/@expressive-code/core/src/helpers/comment-parser.ts b/packages/@expressive-code/core/src/helpers/comment-parser.ts
new file mode 100644
index 00000000..c9ccfae2
--- /dev/null
+++ b/packages/@expressive-code/core/src/helpers/comment-parser.ts
@@ -0,0 +1,350 @@
+type Range = {
+	start: number
+	end: number
+}
+
+interface Comment {
+	outerRange: Range
+	contentRange: Range
+	outerText: string
+	text: string
+	type: 'single' | 'multi'
+}
+
+type ParserState =
+	| {
+			parser: (ctx: ParsingContext) => void
+	  }
+	| {
+			capturing: true
+			parser: (ctx: ParsingContext) => boolean
+	  }
+
+interface ParsingContext {
+	code: string
+	i: number
+	commentStart: number
+	commentContentStart: number
+	escaped: boolean
+	comments: Comment[]
+	stateStack: Array<ParserState>
+	enterState: (state: ParserState) => void
+	exitState: () => void
+	currentState: () => ParserState
+	allCapturingStates: () => ParserState[]
+}
+
+export function parseComments(code: string, language: string) {
+	const parse = createParser(getInitialStateByLanguage(language))
+	return parse(code)
+}
+
+function createParser(initialState: ParserState) {
+	return function (code: string) {
+		const ctx: ParsingContext = {
+			code: code,
+			i: 0,
+			commentStart: -1,
+			commentContentStart: -1,
+			escaped: false,
+			comments: [],
+			stateStack: [],
+			enterState: function (state) {
+				this.stateStack.push(state)
+			},
+			exitState: function () {
+				if (this.stateStack.length > 0) {
+					this.stateStack.pop()
+				}
+			},
+			currentState: function () {
+				return this.stateStack[this.stateStack.length - 1] || initialState
+			},
+			allCapturingStates: function () {
+				return this.stateStack.filter((state) => 'capturing' in state && state.capturing === true)
+			},
+		}
+
+		// Loop through the code, calling the current state function
+		// (note that we also call it once past the end of the code
+		// to ensure that any final state can be handled)
+		for (; ctx.i <= ctx.code.length; ctx.i++) {
+			if (ctx.allCapturingStates().some((state) => state.parser(ctx))) continue
+			ctx.currentState().parser(ctx)
+		}
+		return ctx.comments
+	}
+}
+
+function getInitialStateByLanguage(language: string): ParserState {
+	switch (language) {
+		case 'htm':
+		case 'html':
+		case 'xsl':
+			return { parser: parseBaseHtmlCode }
+		case 'md':
+		case 'markdown':
+			return { parser: parseBaseMdCode }
+		case 'mdx':
+			return { parser: parseBaseMdxCode }
+		default:
+			return { parser: parseBaseJsCode }
+	}
+}
+
+// TODO: HTML can include <script> and <style> elements that switch to JS and CSS parsing!
+
+// Astro:
+// - Frontmatter supports JS comments
+// - Template supports both HTML and JSX comments
+
+// YAML, Vyper
+// # comments
+
+// WebAssembly
+// ;; comments
+
+function parseBaseHtmlCode(ctx: ParsingContext) {
+	if (handleMultiLineComment({ ctx, openingSequence: '<!--', closingSequence: '-->' })) return
+}
+
+function parseBaseMdCode(ctx: ParsingContext) {
+	if (handleFencedCodeBlock({ ctx })) return
+	if (handleMultiLineComment({ ctx, openingSequence: '<!--', closingSequence: '-->' })) return
+}
+
+function parseBaseMdxCode(ctx: ParsingContext) {
+	// if (handleMultiLineComment({ ctx, openingSequence: /^\{\s*\/\*/, closingSequence: /^\*\/\s*}/ })) return
+	if (handleFencedCodeBlock({ ctx })) return
+	if (handleJsx({ ctx })) return
+}
+
+function parseBaseJsCode(ctx: ParsingContext) {
+	if (handleSingleLineComment({ ctx, openingSequence: '//' })) return
+	if (handleMultiLineComment({ ctx, openingSequence: '/*', closingSequence: '*/' })) return
+	if (handleDelimitedString({ ctx, openingSequence: "'", closingSequence: "'" })) return
+	if (handleDelimitedString({ ctx, openingSequence: '"', closingSequence: '"' })) return
+	if (handleJsTemplateString({ ctx })) return
+}
+
+function handleFencedCodeBlock({ ctx }: { ctx: ParsingContext }) {
+	// If we encounter at least 3 backticks, we're potentially entering a fenced code block
+	if (ctx.code.slice(ctx.i, ctx.i + 3) !== '```') return false
+	// Get current line to ensure that there's only whitespace before the backticks
+	// and retrieve the optional language identifier
+	const range = getCurrentLineRange(ctx)
+	const line = ctx.code.slice(range.start, range.end)
+	const match = line.match(/^(?:\s*)(```+)\s*(\S+)?/)
+	if (!match) return false
+	const closingFence = match[1]
+	const language = match[2] || 'plaintext'
+
+	ctx.enterState({ parser: parseFencedCodeBlock, capturing: true })
+	ctx.i = range.end - 1
+	ctx.escaped = false
+	ctx.enterState(getInitialStateByLanguage(language))
+
+	return true
+
+	function parseFencedCodeBlock(ctx: ParsingContext) {
+		// If we encounter at least 3 backticks, we're potentially closing the fenced code block
+		if (ctx.code.slice(ctx.i, ctx.i + 3) === '```') {
+			// Get current line to ensure that there's only whitespace before and after the backticks
+			const range = getCurrentLineRange(ctx)
+			const line = ctx.code.slice(range.start, range.end)
+			const match = line.match(/^(?:\s*)(```+)(?:\s*)$/)
+			// The closing fence must have at least the same amount of backticks
+			if (match && match[1].startsWith(closingFence)) {
+				// Exit all nested states until we reach our initial fenced code block state
+				while (ctx.currentState().parser !== parseFencedCodeBlock) ctx.exitState()
+				// Exit this one as well
+				ctx.exitState()
+				ctx.i = range.end - 1
+				return true
+			}
+		}
+		return false
+	}
+}
+
+function handleDelimitedString({
+	ctx,
+	openingSequence,
+	closingSequence,
+	escapeChar = '\\',
+}: {
+	ctx: ParsingContext
+	openingSequence: string
+	closingSequence: string
+	escapeChar?: string | undefined
+}) {
+	const potentialOpening = ctx.code.slice(ctx.i, ctx.i + openingSequence.length)
+	if (potentialOpening !== openingSequence) return false
+	ctx.enterState({ parser: parseDelimitedString })
+	return true
+
+	function parseDelimitedString(ctx: ParsingContext) {
+		const c = ctx.code[ctx.i]
+		const potentialClosing = ctx.code.slice(ctx.i, ctx.i + closingSequence.length)
+		if (potentialClosing === closingSequence && !ctx.escaped) {
+			ctx.exitState()
+			ctx.i += closingSequence.length - 1
+		}
+		ctx.escaped = c === escapeChar && !ctx.escaped
+	}
+}
+
+function handleJsx({ ctx }: { ctx: ParsingContext }) {
+	const braceStack: number[] = []
+	const c = ctx.code[ctx.i]
+	if (c === '{' && !ctx.escaped) {
+		ctx.enterState({ parser: parseJsxExpression })
+		return true
+	}
+	ctx.escaped = c === '\\' && !ctx.escaped
+	return false
+
+	function parseJsxExpression(ctx: ParsingContext) {
+		const c = ctx.code[ctx.i]
+		if (c === '{') {
+			braceStack.push(ctx.i)
+		} else if (c === '}') {
+			if (braceStack.length > 0) braceStack.pop()
+			if (braceStack.length === 0) return ctx.exitState()
+		}
+		parseBaseJsCode(ctx)
+	}
+}
+
+function handleJsTemplateString({ ctx }: { ctx: ParsingContext }) {
+	if (ctx.code[ctx.i] !== '`') return false
+	const braceStack: number[] = []
+	ctx.enterState({ parser: parseTemplateString })
+	return true
+
+	function parseTemplateString(ctx: ParsingContext) {
+		const c = ctx.code[ctx.i]
+		const next2 = ctx.code.slice(ctx.i, ctx.i + 2)
+		if (c === '`' && !ctx.escaped) {
+			ctx.exitState()
+		} else if (next2 === '${') {
+			ctx.enterState({ parser: parseTemplateExpression })
+			braceStack.push(ctx.i)
+			ctx.i += 1
+		}
+		ctx.escaped = c === '\\' && !ctx.escaped
+	}
+
+	function parseTemplateExpression(ctx: ParsingContext) {
+		const c = ctx.code[ctx.i]
+		if (c === '{') {
+			braceStack.push(ctx.i)
+		} else if (c === '}') {
+			if (braceStack.length > 0) braceStack.pop()
+			if (braceStack.length === 0) return ctx.exitState()
+		}
+		parseBaseJsCode(ctx)
+	}
+}
+
+function handleSingleLineComment({ ctx, openingSequence }: { ctx: ParsingContext; openingSequence: string }) {
+	return handleCommentStart({ ctx, openingSequence, targetState: { parser: parseSingleLineComment } })
+
+	function parseSingleLineComment(ctx: ParsingContext) {
+		if (ctx.code[ctx.i] === '\n' || ctx.i === ctx.code.length) {
+			ctx.comments.push(
+				createCommentFromRanges({
+					fullCode: ctx.code,
+					outerRange: { start: ctx.commentStart, end: ctx.i },
+					contentRange: { start: ctx.commentContentStart, end: ctx.i },
+					type: 'single',
+				})
+			)
+			ctx.exitState()
+		}
+	}
+}
+
+function handleMultiLineComment({ ctx, openingSequence, closingSequence }: { ctx: ParsingContext; openingSequence: string | RegExp; closingSequence: string | RegExp }) {
+	return handleCommentStart({ ctx, openingSequence, targetState: { parser: parseMultiLineComment } })
+
+	function parseMultiLineComment(ctx: ParsingContext) {
+		const match = matchAhead(ctx, closingSequence) || matchEof(ctx)
+		if (match) {
+			ctx.comments.push(
+				createCommentFromRanges({
+					fullCode: ctx.code,
+					outerRange: { start: ctx.commentStart, end: match.start + match.length },
+					contentRange: { start: ctx.commentContentStart, end: match.start },
+					type: 'multi',
+				})
+			)
+			ctx.exitState()
+			ctx.i = match.start + match.length - 1
+		}
+	}
+}
+
+function handleCommentStart({ ctx, openingSequence, targetState }: { ctx: ParsingContext; openingSequence: string | RegExp; targetState: ParserState }) {
+	const match = matchAhead(ctx, openingSequence)
+	if (!match) return false
+	ctx.enterState(targetState)
+	ctx.commentStart = match.start
+	ctx.commentContentStart = match.start + match.length
+	ctx.i = ctx.commentContentStart - 1
+	return true
+}
+
+function createCommentFromRanges({ fullCode, ...commentProps }: { fullCode: string } & Omit<Comment, 'outerText' | 'text'>): Comment {
+	return {
+		...commentProps,
+		outerText: fullCode.slice(commentProps.outerRange.start, commentProps.outerRange.end),
+		text: fullCode.slice(commentProps.contentRange.start, commentProps.contentRange.end),
+	}
+}
+
+function matchAhead(ctx: ParsingContext, sequence: string | RegExp): { start: number; length: number } | undefined {
+	if (sequence instanceof RegExp) {
+		const searchWindow = ctx.code.slice(ctx.i, ctx.i + 40)
+		const match = searchWindow.match(sequence)
+		if (!match) return
+		return {
+			start: ctx.i + (match.index ?? 0),
+			length: match[0].length,
+		}
+	}
+	const searchWindow = ctx.code.slice(ctx.i, ctx.i + sequence.length)
+	if (searchWindow !== sequence) return
+	return {
+		start: ctx.i,
+		length: sequence.length,
+	}
+}
+
+function matchEof(ctx: ParsingContext): { start: number; length: number } | undefined {
+	if (ctx.i < ctx.code.length) return
+	return {
+		start: ctx.i,
+		length: 0,
+	}
+}
+
+function getCurrentLineRange(ctx: ParsingContext): { start: number; end: number } {
+	const codeLength = ctx.code.length
+	const range = { start: 0, end: codeLength }
+	for (let i = ctx.i - 1; i >= 0; i--) {
+		const c = ctx.code[i]
+		if (c === '\n' || c === '\r') {
+			range.start = i + 1
+			break
+		}
+	}
+	for (let i = ctx.i; i < codeLength; i++) {
+		const c = ctx.code[i]
+		if (c === '\n' || c === '\r') {
+			range.end = i
+			break
+		}
+	}
+	return range
+}
diff --git a/packages/@expressive-code/core/test/comment-parser.test.ts b/packages/@expressive-code/core/test/comment-parser.test.ts
new file mode 100644
index 00000000..245d63c2
--- /dev/null
+++ b/packages/@expressive-code/core/test/comment-parser.test.ts
@@ -0,0 +1,223 @@
+import { describe, expect, test } from 'vitest'
+import { parseComments } from '../src/helpers/comment-parser'
+
+describe('Comment parser', () => {
+	describe('Finding comments in JS code', () => {
+		test('Single-line comments', () => {
+			const code = `
+function test(input) { //1.1
+	console.log(input); // 1.2
+}
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([
+				{ outerText: '//1.1', text: '1.1', type: 'single' },
+				{ outerText: '// 1.2', text: ' 1.2', type: 'single' },
+			])
+		})
+
+		test('Multi-line comment', () => {
+			const comment = `
+	/*
+	console.log(input); // 1.2
+	*/
+			`.trim()
+			const code = `
+function test(input) {
+	${comment}
+}
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([
+				{
+					outerText: comment,
+					text: comment.slice(2, -2),
+					type: 'multi',
+				},
+			])
+		})
+
+		test('Single-line comment syntax inside a string', () => {
+			const code = `
+console.log('hi // this is not a comment') // but this is!
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([{ outerText: '// but this is!', text: ' but this is!', type: 'single' }])
+		})
+
+		test('Single-line comment syntax inside a string with escaped quotes', () => {
+			const code = `
+console.log('hi \\')// this is not a comment') // but this is!
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([{ outerText: '// but this is!', text: ' but this is!', type: 'single' }])
+		})
+
+		test('Multi-line comment syntax inside a string', () => {
+			const code = `
+console.log('hi /* this is not a comment */') // but this is!
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([{ outerText: '// but this is!', text: ' but this is!', type: 'single' }])
+		})
+
+		test('Actual multi-line comment inside a template string expression', () => {
+			const code = `
+console.log(\`hi \${/* this is a comment! //ok */ 'mom'}\`) // wow
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([
+				{ outerText: '/* this is a comment! //ok */', text: ' this is a comment! //ok ', type: 'multi' },
+				{ outerText: '// wow', text: ' wow', type: 'single' },
+			])
+		})
+
+		test('Template literals with nested template literals', () => {
+			const code = `
+const item = "coffee"; // but what about tea?
+const temp = "hot";
+const order = \`I ordered a \${\`\${temp} \${item}\` /* nested comment */
+}, /* not a comment */ // neither this
+and it was \${\`absolutely \${\`delicious\`}\`}.\`;
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([
+				{ outerText: '// but what about tea?', text: ' but what about tea?', type: 'single' },
+				{ outerText: '/* nested comment */', text: ' nested comment ', type: 'multi' },
+			])
+		})
+
+		test('Template literals with complex nested JS code', () => {
+			const code = `
+const target = 'world'; // Comment 1
+console.log(\`Hello \${target}! \${(() => {
+	const date = /*}sneaky{*/ new Date(); // Comment 2
+	return \`The {date today is \${date.getFullYear()}-\${date.getMonth() + 1}-\${date.getDate()}.\`;
+})()}\`) // Comment 3
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([
+				{ outerText: '// Comment 1', text: ' Comment 1', type: 'single' },
+				{ outerText: '/*}sneaky{*/', text: '}sneaky{', type: 'multi' },
+				{ outerText: '// Comment 2', text: ' Comment 2', type: 'single' },
+				{ outerText: '// Comment 3', text: ' Comment 3', type: 'single' },
+			])
+		})
+
+		test('Commented out multi-line comment', () => {
+			const code = `
+// This multi-line comment has been commented out:
+// /*
+console.log(someString);
+// */
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([
+				{ outerText: '// This multi-line comment has been commented out:', type: 'single' },
+				{ outerText: '// /*', text: ' /*', type: 'single' },
+				{ outerText: '// */', text: ' */', type: 'single' },
+			])
+		})
+
+		test('Comments in JSX code', () => {
+			const multiLineComment = `
+		/*
+  			Comments can span
+			multiple lines.
+		*/
+			`.trim()
+			const code = `
+render() {
+	return (
+		<div>
+			<p>Hi!{/* This is a JSX comment! */}</p>
+			{${multiLineComment}}
+		</div>
+	)
+}
+			`.trim()
+			expect(parseComments(code, 'js')).toMatchObject([
+				{ outerText: '/* This is a JSX comment! */', text: ' This is a JSX comment! ', type: 'multi' },
+				{ outerText: multiLineComment, text: multiLineComment.slice(2, -2), type: 'multi' },
+			])
+		})
+	})
+
+	describe('Finding JSX comments in MDX code', () => {
+		test('Single-line comments', () => {
+			const code = `
+{//}
+//1.1
+function test(input) {
+	console.log(input); // 1.2
+}
+}
+			`.trim()
+			expect(parseComments(code, 'mdx')).toMatchObject([
+				{ outerText: '//}', text: '}', type: 'single' },
+				{ outerText: '//1.1', text: '1.1', type: 'single' },
+				{ outerText: '// 1.2', text: ' 1.2', type: 'single' },
+			])
+		})
+		test('Multi-line comment', () => {
+			const comment = `
+	{/*
+	console.log(input); // 1.2
+	*/}
+			`.trim()
+			const code = `
+function test(input) {
+	${comment}
+}
+			`.trim()
+			expect(parseComments(code, 'mdx')).toMatchObject([
+				{
+					// TODO: Extend outerText of JSX expressions that only contain a single comment
+					//outerText: comment,
+					text: comment.slice(3, -3),
+					type: 'multi',
+				},
+			])
+		})
+	})
+
+	describe('Finding comments in code nested in MDX fenced code blocks', () => {
+		test('Comments in nested JS', () => {
+			const code = `
+{/* 1st JSX comment in MDX */}
+# Test // This is not a comment
+// This neither
+\`\`\`js
+function test(input) { //1.1
+	console.log(input); // 1.2
+}
+\`\`\`
+// Also not a comment
+{/* 2nd JSX comment in MDX */}
+			`.trim()
+			expect(parseComments(code, 'mdx')).toMatchObject([
+				{ text: ' 1st JSX comment in MDX ', type: 'multi' },
+				{ outerText: '//1.1', text: '1.1', type: 'single' },
+				{ outerText: '// 1.2', text: ' 1.2', type: 'single' },
+				{ text: ' 2nd JSX comment in MDX ', type: 'multi' },
+			])
+		})
+		test('Multiple levels of nested code blocks', () => {
+			const code = `
+{/* 1st JSX comment in MDX */}
+# Test // This is not a comment
+\`\`\`\`md
+// This neither
+<!-- 1st HTML comment in MD -->
+\`\`\`js
+function test(input) { //1.1
+	console.log(input); // 1.2
+}
+\`\`\`
+// Also not a comment
+<!-- 2nd HTML comment in MD -->
+\`\`\`\`
+{/* 2nd JSX comment in MDX */}
+			`.trim()
+			expect(parseComments(code, 'mdx')).toMatchObject([
+				{ text: ' 1st JSX comment in MDX ', type: 'multi' },
+				{ text: ' 1st HTML comment in MD ', type: 'multi' },
+				{ outerText: '//1.1', text: '1.1', type: 'single' },
+				{ outerText: '// 1.2', text: ' 1.2', type: 'single' },
+				{ text: ' 2nd HTML comment in MD ', type: 'multi' },
+				{ text: ' 2nd JSX comment in MDX ', type: 'multi' },
+			])
+		})
+	})
+})