fix(cli): retain path based test mode inference (#11878)

cli/tests/integration/test_tests.rs

@@ -67,6 +67,12 @@ itest!(doc {
   output: "test/doc.out",
 });
 
+itest!(doc_only {
+  args: "test --doc --allow-all test/doc_only",
+  exit_code: 0,
+  output: "test/doc_only.out",
+});
+
 itest!(markdown {
   args: "test --doc --allow-all test/markdown.md",
   exit_code: 1,

cli/tests/testdata/test/doc_only.out

@@ -0,0 +1,5 @@
+Check [WILDCARD]/test/doc_only/mod.ts$2-5.ts
+running 0 tests from [WILDCARD]/test/doc_only/mod.ts
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out ([WILDCARD])
+

cli/tests/testdata/test/doc_only/mod.ts

@@ -0,0 +1,10 @@
+/**
+ * ```ts
+ * import "./mod.ts";
+ * ```
+ */
+Deno.test("unreachable", function () {
+  throw new Error(
+    "modules that don't end with _test are scanned for documentation tests only should not be executed",
+  );
+});

cli/tools/test.rs

@@ -757,9 +757,7 @@ async fn fetch_specifiers_with_test_mode(
       .fetch(specifier, &mut Permissions::allow_all())
       .await?;
 
-    if file.media_type != MediaType::Unknown {
+    if file.media_type == MediaType::Unknown {
-      *mode = TestMode::Both
-    } else {
       *mode = TestMode::Documentation
     }
   }