Show diff or file content in fzf_search_git_status

functions/__fzf_git_diff.fish

@@ -0,0 +1,13 @@
+function __fzf_git_diff
+    switch (string sub --length 2 $argv[1])
+        # Untracked filed
+        case '\?\?'
+            bat $argv[2]
+        # Deleted files, show the file content in previous commit
+        case '?D' 'D?'
+            git show HEAD:$argv[2]
+        # Other files, show the diff compared to last commit (unstaged & staged changes)
+        case '*'
+            git diff --color HEAD $argv[2]
+    end
+end

functions/__fzf_search_git_status.fish

@@ -5,7 +5,9 @@ function __fzf_search_git_status --description "Search the output of git status.
         set selected_paths (
             # Pass configuration color.status=always to force status to use colors even though output is sent to a pipe
             git -c color.status=always status --short |
-            fzf --ansi --multi --query=(commandline --current-token)
+            fzf --ansi --multi \
+                --query=(commandline --current-token) \
+                --preview="__fzf_git_diff {} {2}"
         )
         if test $status -eq 0
             # git status --short automatically escapes the paths of most files for us so not going to bother trying to handle