diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 3919366..8f3770d 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -1,6 +1,7 @@
 # Description: This workflow runs tests for hustcer/deepseek-review.
 # REF:
 #   - https://github.com/vyadh/nutest/blob/main/.github/workflows/tests.yaml
+#   - https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/store-information-in-variables#default-environment-variables
 
 name: Run Tests
 
diff --git a/tests/test-common.nu b/tests/test-common.nu
index 45746ff..a97a570 100644
--- a/tests/test-common.nu
+++ b/tests/test-common.nu
@@ -1,7 +1,10 @@
 
 use std/assert
 
-use ../nu/common.nu [compare-ver, 'from env', is-installed, has-ref, git-check, compact-record]
+use ../nu/common.nu [
+  compare-ver, 'from env', is-installed, has-ref,
+  git-check, compact-record, is-repo, windows?, mac?,
+]
 
 #[test]
 def 'compare-ver：v1.0.0 is greater than v0.999.0' [] {
@@ -52,6 +55,11 @@ def 'has-ref：git repo should has HEAD ref' [] {
   assert equal (has-ref 0000) false
 }
 
+#[test]
+def 'is-repo：current dir is a git repo' [] {
+  assert equal (is-repo) true
+}
+
 #[test]
 def 'git-check：current dir is a git repo' [] {
   assert equal (git-check (pwd) --check-repo=1) true
@@ -62,3 +70,31 @@ def 'compact-record：should work as expected' [] {
   assert equal ({a: null, b: '', c: 'abc' } | compact-record) { c: 'abc' }
   assert equal ({a: null, b: 0, c: 1, e: { f: 'g' } } | compact-record) { b: 0, c: 1, e: { f: 'g' } }
 }
+
+#[test]
+def 'OS check should work as expected' [] {
+  # `$env.RUNNER_OS` Possible values are Linux, Windows, or macOS in GitHub Actions
+  match $nu.os-info.name {
+    'windows' => {
+      assert equal (mac?) false
+      assert equal (windows?) true
+      if ($env.RUNNER_OS | is-not-empty) {
+        assert equal $env.RUNNER_OS Windows
+      }
+    }
+    'macos' => {
+      assert equal (mac?) true
+      assert equal (windows?) false
+      if ($env.RUNNER_OS | is-not-empty) {
+        assert equal $env.RUNNER_OS macOS
+      }
+    }
+    _ => {
+      assert equal (mac?) false
+      assert equal (windows?) false
+      if ($env.RUNNER_OS | is-not-empty) {
+        assert equal $env.RUNNER_OS Linux
+      }
+    }
+  }
+}