diff --git a/tests/modules/programs/diff-highlight/default.nix b/tests/modules/programs/diff-highlight/default.nix
new file mode 100644
index 00000000..5bdbe52d
--- /dev/null
+++ b/tests/modules/programs/diff-highlight/default.nix
@@ -0,0 +1,5 @@
+{
+  diff-highlight-basic = ./diff-highlight-basic.nix;
+  diff-highlight-with-git-integration = ./diff-highlight-with-git-integration.nix;
+  diff-highlight-migration = ./diff-highlight-migration.nix;
+}
diff --git a/tests/modules/programs/diff-highlight/diff-highlight-basic.nix b/tests/modules/programs/diff-highlight/diff-highlight-basic.nix
new file mode 100644
index 00000000..8fb7b655
--- /dev/null
+++ b/tests/modules/programs/diff-highlight/diff-highlight-basic.nix
@@ -0,0 +1,16 @@
+{
+  programs.diff-highlight = {
+    enable = true;
+    pagerOpts = [
+      "--tabs=4"
+      "-RFX"
+    ];
+  };
+  programs.git.enable = true;
+
+  nmt.script = ''
+    # Git config should NOT contain diff-highlight configuration since enableGitIntegration is false by default
+    assertFileNotRegex home-files/.config/git/config 'pager = .*/diff-highlight'
+    assertFileNotRegex home-files/.config/git/config 'diffFilter = .*/diff-highlight'
+  '';
+}
diff --git a/tests/modules/programs/diff-highlight/diff-highlight-migration.nix b/tests/modules/programs/diff-highlight/diff-highlight-migration.nix
new file mode 100644
index 00000000..7f151655
--- /dev/null
+++ b/tests/modules/programs/diff-highlight/diff-highlight-migration.nix
@@ -0,0 +1,33 @@
+{
+  lib,
+  options,
+  ...
+}:
+
+{
+  programs.git = {
+    enable = true;
+    diff-highlight = {
+      enable = true;
+      pagerOpts = [
+        "--tabs=4"
+        "-RFX"
+      ];
+    };
+  };
+
+  test.asserts.warnings.expected = [
+    "The option `programs.git.diff-highlight.pagerOpts' defined in ${lib.showFiles options.programs.git.diff-highlight.pagerOpts.files} has been renamed to `programs.diff-highlight.pagerOpts'."
+    "The option `programs.git.diff-highlight.enable' defined in ${lib.showFiles options.programs.git.diff-highlight.enable.files} has been renamed to `programs.diff-highlight.enable'."
+    "`programs.diff-highlight.enableGitIntegration` automatic enablement is deprecated. Please explicitly set `programs.diff-highlight.enableGitIntegration = true`."
+  ];
+
+  nmt.script = ''
+    # Git config should contain diff-highlight configuration (backward compatibility)
+    assertFileExists home-files/.config/git/config
+    assertFileContains home-files/.config/git/config '[core]'
+    assertFileRegex home-files/.config/git/config 'pager = .*/diff-highlight.*less'
+    assertFileContains home-files/.config/git/config '[interactive]'
+    assertFileRegex home-files/.config/git/config 'diffFilter = .*/diff-highlight'
+  '';
+}
diff --git a/tests/modules/programs/diff-highlight/diff-highlight-with-git-integration.nix b/tests/modules/programs/diff-highlight/diff-highlight-with-git-integration.nix
new file mode 100644
index 00000000..674329e4
--- /dev/null
+++ b/tests/modules/programs/diff-highlight/diff-highlight-with-git-integration.nix
@@ -0,0 +1,20 @@
+{
+  programs.diff-highlight = {
+    enable = true;
+    enableGitIntegration = true;
+    pagerOpts = [
+      "--tabs=4"
+      "-RFX"
+    ];
+  };
+
+  programs.git.enable = true;
+
+  nmt.script = ''
+    assertFileExists home-files/.config/git/config
+    assertFileContains home-files/.config/git/config '[core]'
+    assertFileRegex home-files/.config/git/config 'pager = .*/diff-highlight.*less'
+    assertFileContains home-files/.config/git/config '[interactive]'
+    assertFileRegex home-files/.config/git/config 'diffFilter = .*/diff-highlight'
+  '';
+}