chore: deprecate test itests (#25512)

This PR is part of #22907

---------

Signed-off-by: HasanAlrimawi <141642411+HasanAlrimawi@users.noreply.github.com>
Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

3 files changed, 43 insertions, 0 deletions

diff --git a/tests/specs/test/markdown/__test__.jsonc b/tests/specs/test/markdown/__test__.jsonc
new file mode 100644
index 000000000..558106d55
--- /dev/null
+++ b/tests/specs/test/markdown/__test__.jsonc
@@ -0,0 +1,5 @@
+{
+  "args": "test --doc --allow-all main.md",
+  "exitCode": 1,
+  "output": "main.out"
+}
diff --git a/tests/specs/test/markdown/main.md b/tests/specs/test/markdown/main.md
new file mode 100644
index 000000000..d18dbd108
--- /dev/null
+++ b/tests/specs/test/markdown/main.md
@@ -0,0 +1,31 @@
+# Documentation
+
+The following block does not have a language attribute and should be ignored:
+
+```
+This is a fenced block without attributes, it's invalid and it should be ignored.
+```
+
+The following block should be given a js extension on extraction:
+
+```js
+console.log("js");
+```
+
+The following block should be given a ts extension on extraction:
+
+```ts
+console.log("ts");
+```
+
+The following example contains the ignore attribute and will be ignored:
+
+```ts ignore
+const value: Invalid = "ignored";
+```
+
+The following example will trigger the type-checker to fail:
+
+```ts
+const a: string = 42;
+```
diff --git a/tests/specs/test/markdown/main.out b/tests/specs/test/markdown/main.out
new file mode 100644
index 000000000..30327c72f
--- /dev/null
+++ b/tests/specs/test/markdown/main.out
@@ -0,0 +1,7 @@
+Check [WILDCARD]/main.md$11-14.js
+Check [WILDCARD]/main.md$17-20.ts
+Check [WILDCARD]/main.md$29-32.ts
+error: TS2322 [ERROR]: Type 'number' is not assignable to type 'string'.
+const a: string = 42;
+      ^
+    at [WILDCARD]/main.md$29-32.ts:1:7