Add helper fn to check whether the repository WD is dirty

libimagstorestdhook/src/vcs/git/runtime.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use git2::Repository;
+use git2::{Index, Repository};
 use toml::Value;
 
 use libimagerror::into::IntoError;
@@ -154,5 +154,25 @@ impl Runtime {
         .map_dbg_str("[GIT CREATE HOOK]: Branch checked out")
     }
 
+    /// Check whether the WD is "dirty" - whether there is a diff to the repository
+    /// This function returns false if there is no `Repository` object in the `Runtime`
+    pub fn repo_is_dirty(&self, index: &Index) -> bool {
+        match self.repository.as_ref() {
+            Some(repo) => {
+                repo.diff_index_to_workdir(Some(index), None)
+                    .map_dbg_str("Fetched diff: Index <-> WD")
+                    .map_dbg_err_str("Failed to fetch diff: Index <-> WD")
+                    .map(|diff| diff.deltas().count() != 0)
+                    .unwrap_or(false)
+            },
+
+            None => {
+                debug!("No repository: Cannot fetch diff: Index <-> WD");
+                false
+            }
+        }
+
+    }
+
 }