fix(loader): allow filenames with dots (#5529)

(cherry picked from commit 4cb11acd46)

crates/cli/src/tests/detect_language.rs

@@ -127,6 +127,52 @@ fn detect_language_by_double_barrel_file_extension() {
     );
 }
 
+#[test]
+fn detect_language_with_dots_in_filename() {
+    let blade_dir = tree_sitter_dir(
+        r#"{
+  "grammars": [
+    {
+      "name": "blade_dots",
+      "path": ".",
+      "scope": "source.blade",
+      "file-types": [
+        "blade.php"
+      ]
+    },
+    {
+      "name": "php_dots",
+      "path": ".",
+      "scope": "source.php",
+      "file-types": [
+        "php"
+      ]
+    }
+  ],
+  "metadata": {
+    "version": "0.0.1"
+  }
+}
+"#,
+        "blade_dots",
+    );
+
+    let mut loader = Loader::with_parser_lib_path(scratch_dir().to_path_buf());
+    let config = loader
+        .find_language_configurations_at_path(blade_dir.path(), false)
+        .unwrap();
+
+    // this is just to validate that we can read the tree-sitter.json correctly
+    assert_eq!(config[0].scope.as_ref().unwrap(), "source.blade");
+
+    let file_name = blade_dir.path().join("foo.bar.baz.blade.php");
+    fs::write(&file_name, "").unwrap();
+    assert_eq!(
+        get_lang_scope(&loader, &file_name),
+        Some("source.blade".into())
+    );
+}
+
 #[test]
 fn detect_language_without_filename() {
     let gitignore_dir = tree_sitter_dir(

crates/loader/src/loader.rs

@@ -810,8 +810,11 @@ impl Loader {
                     path = PathBuf::from(path.file_stem()?.to_os_string());
                 }
                 extensions.reverse();
-                self.language_configuration_ids_by_file_type
-                    .get(&extensions.join("."))
+                // Try longest extension suffixs first (e.g. "foo.bar.baz"->"bar.baz"->"baz"),
+                // stopping at the first match.
+                (0..extensions.len())
+                    .map(|i| extensions[i..].join("."))
+                    .find_map(|key| self.language_configuration_ids_by_file_type.get(&key))
             });
 
         if let Some(configuration_ids) = configuration_ids {