Support XDG_CONFIG_HOME git config files

src/syntax_mapping.rs

@@ -103,6 +103,43 @@ impl<'a> SyntaxMapping<'a> {
             .insert("*.hook", MappingTarget::MapTo("INI"))
             .unwrap();
 
+        if let Some(xdg_config_home) = std::env::var_os("XDG_CONFIG_HOME") {
+            let git_config_path = Path::new(&xdg_config_home).join("git");
+
+            mapping
+                .insert(
+                    &git_config_path
+                        .join("config")
+                        .into_os_string()
+                        .to_str()
+                        .unwrap(),
+                    MappingTarget::MapTo("Git Config"),
+                )
+                .unwrap();
+
+            mapping
+                .insert(
+                    &git_config_path
+                        .join("ignore")
+                        .into_os_string()
+                        .to_str()
+                        .unwrap(),
+                    MappingTarget::MapTo("Git Ignore"),
+                )
+                .unwrap();
+
+            mapping
+                .insert(
+                    &git_config_path
+                        .join("attributes")
+                        .into_os_string()
+                        .to_str()
+                        .unwrap(),
+                    MappingTarget::MapTo("Git Attributes"),
+                )
+                .unwrap();
+        }
+
         mapping
     }
 
@@ -155,6 +192,23 @@ fn basic() {
     );
 }
 
+#[test]
+fn git_xdg_config_home() {
+    use assert_cmd::Command;
+    let mut cmd = Command::cargo_bin("bat").unwrap();
+    let mut map = SyntaxMapping::builtin();
+
+    cmd.env("XDG_CONFIG_HOME", "/foo/bar");
+
+    map.insert("/foo/bar/git/config", MappingTarget::MapTo("Git Config"))
+        .ok();
+
+    assert_eq!(
+        map.get_syntax_for("/foo/bar/git/config"),
+        Some(MappingTarget::MapTo("Git Config"))
+    );
+}
+
 #[test]
 fn user_can_override_builtin_mappings() {
     let mut map = SyntaxMapping::builtin();