From 8db3a9546b59fdd5e7203f2e63a828e3c5108e7e Mon Sep 17 00:00:00 2001
From: Geert-Jan Zwiers <34610306+GJZwiers@users.noreply.github.com>
Date: Fri, 11 Mar 2022 02:14:32 +0100
Subject: [PATCH] fix(test): skip typechecking for blocks inside HTML comments
 (#13889)

---
 cli/tests/integration/test_tests.rs           |  6 ++++
 .../testdata/test/markdown_with_comment.md    | 36 +++++++++++++++++++
 .../testdata/test/markdown_with_comment.out   |  5 +++
 cli/tools/test.rs                             | 11 +++++-
 4 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 cli/tests/testdata/test/markdown_with_comment.md
 create mode 100644 cli/tests/testdata/test/markdown_with_comment.out

diff --git a/cli/tests/integration/test_tests.rs b/cli/tests/integration/test_tests.rs
index 6424dabd0e..f3cf9ebd08 100644
--- a/cli/tests/integration/test_tests.rs
+++ b/cli/tests/integration/test_tests.rs
@@ -103,6 +103,12 @@ itest!(markdown_full_block_names {
   output: "test/markdown_full_block_names.out",
 });
 
+itest!(markdown_ignore_html_comment {
+  args: "test --doc --allow-all test/markdown_with_comment.md",
+  exit_code: 1,
+  output: "test/markdown_with_comment.out",
+});
+
 itest!(text {
   args: "test --doc --allow-all test/text.md",
   exit_code: 0,
diff --git a/cli/tests/testdata/test/markdown_with_comment.md b/cli/tests/testdata/test/markdown_with_comment.md
new file mode 100644
index 0000000000..886e881033
--- /dev/null
+++ b/cli/tests/testdata/test/markdown_with_comment.md
@@ -0,0 +1,36 @@
+# Documentation
+
+The following examples are inside HTML comments and will not trigger the
+type-checker:
+
+<!-- ```ts ignore
+const value: Invalid = "ignored";
+``` -->
+
+<!--
+```ts
+const a: string = 42;
+```
+-->
+
+<!--
+
+This is a comment.
+
+```ts
+const a: string = 42;
+```
+
+Something something more comments.
+
+```typescript
+const a: boolean = "true";
+```
+
+-->
+
+The following example will trigger the type-checker to fail:
+
+```ts
+const a: string = 42;
+```
diff --git a/cli/tests/testdata/test/markdown_with_comment.out b/cli/tests/testdata/test/markdown_with_comment.out
new file mode 100644
index 0000000000..b202919d8f
--- /dev/null
+++ b/cli/tests/testdata/test/markdown_with_comment.out
@@ -0,0 +1,5 @@
+Check [WILDCARD]/test/markdown_with_comment.md$34-37.ts
+error: TS2322 [ERROR]: Type 'number' is not assignable to type 'string'.
+const a: string = 42;
+      ^
+    at [WILDCARD]/test/markdown_with_comment.md$34-37.ts:1:7
diff --git a/cli/tools/test.rs b/cli/tools/test.rs
index 74646986d2..61a37c7ff5 100644
--- a/cli/tools/test.rs
+++ b/cli/tools/test.rs
@@ -543,6 +543,10 @@ fn extract_files_from_regex_blocks(
   let files = blocks_regex
     .captures_iter(source)
     .filter_map(|block| {
+      if block.get(1) == None {
+        return None;
+      }
+
       let maybe_attributes: Option<Vec<_>> = block
         .get(1)
         .map(|attributes| attributes.as_str().split(' ').collect());
@@ -663,7 +667,12 @@ fn extract_files_from_fenced_blocks(
   source: &str,
   media_type: MediaType,
 ) -> Result<Vec<File>, AnyError> {
-  let blocks_regex = Regex::new(r"```([^\r\n]*)\r?\n([\S\s]*?)```")?;
+  // The pattern matches code blocks as well as anything in HTML comment syntax,
+  // but it stores the latter without any capturing groups. This way, a simple
+  // check can be done to see if a block is inside a comment (and skip typechecking)
+  // or not by checking for the presence of capturing groups in the matches.
+  let blocks_regex =
+    Regex::new(r"(?s)<!--.*?-->|```([^\r\n]*)\r?\n([\S\s]*?)```")?;
   let lines_regex = Regex::new(r"(?:\# ?)?(.*)")?;
 
   extract_files_from_regex_blocks(