From 3629e68250984b73549c25488fd8f7821e404a73 Mon Sep 17 00:00:00 2001
From: Gerrit Birkeland <gerrit@gerritbirkeland.com>
Date: Thu, 7 Oct 2021 17:22:36 -0600
Subject: [PATCH] Fix rendering of `@example` comment blocks (#132821)

---
 .../src/test/unit/previewer.test.ts           | 49 ++++++++++++++++++-
 .../src/utils/previewer.ts                    |  6 +--
 2 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/extensions/typescript-language-features/src/test/unit/previewer.test.ts b/extensions/typescript-language-features/src/test/unit/previewer.test.ts
index 040ffcfef6675..764cb1a3f811b 100644
--- a/extensions/typescript-language-features/src/test/unit/previewer.test.ts
+++ b/extensions/typescript-language-features/src/test/unit/previewer.test.ts
@@ -87,6 +87,54 @@ suite('typescript.previewer', () => {
 			'*@param* `parámetroConDiacríticos` — this will not');
 	});
 
+	test('Should render @example blocks as code', () => {
+		assert.strictEqual(
+			tagsMarkdownPreview([
+				{
+					name: 'example',
+					text: 'code();'
+				}
+			], noopToResource),
+			'*@example*  \n```\ncode();\n```'
+		);
+	});
+
+	test('Should not render @example blocks as code as if they contain a codeblock', () => {
+		assert.strictEqual(
+			tagsMarkdownPreview([
+				{
+					name: 'example',
+					text: 'Not code\n```\ncode();\n```'
+				}
+			], noopToResource),
+			'*@example*  \nNot code\n```\ncode();\n```'
+		);
+	});
+
+	test('Should render @example blocks as code if they contain a <caption>', () => {
+		assert.strictEqual(
+			tagsMarkdownPreview([
+				{
+					name: 'example',
+					text: '<caption>Not code</caption>\ncode();'
+				}
+			], noopToResource),
+			'*@example*  \nNot code\n```\ncode();\n```'
+		);
+	});
+
+	test('Should not render @example blocks as code if they contain a <caption> and a codeblock', () => {
+		assert.strictEqual(
+			tagsMarkdownPreview([
+				{
+					name: 'example',
+					text: '<caption>Not code</caption>\n```\ncode();\n```'
+				}
+			], noopToResource),
+			'*@example*  \nNot code\n```\ncode();\n```'
+		);
+	});
+
 	test('Should render @linkcode symbol name as code', async () => {
 		assert.strictEqual(
 			plainWithLinks([
@@ -128,4 +176,3 @@ suite('typescript.previewer', () => {
 			'a [`husky`](file:///path/file.ts#L7%2C5) b');
 	});
 });
-
diff --git a/extensions/typescript-language-features/src/utils/previewer.ts b/extensions/typescript-language-features/src/utils/previewer.ts
index 93a88382500d4..7ce0e7713daed 100644
--- a/extensions/typescript-language-features/src/utils/previewer.ts
+++ b/extensions/typescript-language-features/src/utils/previewer.ts
@@ -39,9 +39,9 @@ function getTagBodyText(
 		return undefined;
 	}
 
-	// Convert to markdown code block if it is not already one
+	// Convert to markdown code block if it does not already contain one
 	function makeCodeblock(text: string): string {
-		if (text.match(/^\s*[~`]{3}/g)) {
+		if (text.match(/^\s*[~`]{3}/m)) {
 			return text;
 		}
 		return '```\n' + text + '\n```';
@@ -53,7 +53,7 @@ function getTagBodyText(
 			// check for caption tags, fix for #79704
 			const captionTagMatches = text.match(/<caption>(.*?)<\/caption>\s*(\r\n|\n)/);
 			if (captionTagMatches && captionTagMatches.index === 0) {
-				return captionTagMatches[1] + '\n\n' + makeCodeblock(text.substr(captionTagMatches[0].length));
+				return captionTagMatches[1] + '\n' + makeCodeblock(text.substr(captionTagMatches[0].length));
 			} else {
 				return makeCodeblock(text);
 			}