diff --git a/tests/unit/plugins/modules/helper.py b/tests/unit/plugins/modules/helper.py
index 2464f280dec..4b0f17b362c 100644
--- a/tests/unit/plugins/modules/helper.py
+++ b/tests/unit/plugins/modules/helper.py
@@ -72,7 +72,13 @@ def _test_module(mocker, capfd, patch_ansible_module, test_case):
             """
             Run unit tests for each test case in self.test_cases
             """
-            patch_ansible_module(test_case.input)
+            args = {}
+            args.update(test_case.input)
+            if test_case.flags.get("check"):
+                args["_ansible_check_mode"] = test_case.flags.get("check")
+            if test_case.flags.get("diff"):
+                args["_ansible_diff"] = test_case.flags.get("diff")
+            patch_ansible_module(args)
             self.runner.run(mocker, capfd, test_case)
 
         self.add_func_to_test_module("test_module", _test_module)
diff --git a/tests/unit/plugins/modules/test_gio_mime.yaml b/tests/unit/plugins/modules/test_gio_mime.yaml
index 6ed5af5d497..0d98f255032 100644
--- a/tests/unit/plugins/modules/test_gio_mime.yaml
+++ b/tests/unit/plugins/modules/test_gio_mime.yaml
@@ -39,8 +39,15 @@ test_cases:
     output:
       handler: google-chrome.desktop
       changed: true
+      stdout: Module executed in check mode
+      diff:
+        before:
+          handler: null
+        after:
+          handler: google-chrome.desktop
     flags:
-      skip: test helper does not support check mode yet
+      check: true
+      diff: true
     mocks:
       run_command:
         - command: [/testbin/gio, --version]
@@ -54,18 +61,45 @@ test_cases:
           out: ''
           err: >
             No default applications for “x-scheme-handler/http”
-        - command: [/testbin/gio, mime, x-scheme-handler/http, google-chrome.desktop]
+  - id: test_set_handler_idempot
+    input:
+      handler: google-chrome.desktop
+      mime_type: x-scheme-handler/http
+    output:
+      handler: google-chrome.desktop
+      changed: false
+    mocks:
+      run_command:
+        - command: [/testbin/gio, --version]
           environ: *env-def
           rc: 0
-          out: "Set google-chrome.desktop as the default for x-scheme-handler/http\n"
+          out: "2.80.0\n"
           err: ''
-  - id: test_set_handler_idempot
+        - command: [/testbin/gio, mime, x-scheme-handler/http]
+          environ: *env-def
+          rc: 0
+          out: |
+            Default application for “x-scheme-handler/https”: google-chrome.desktop
+            Registered applications:
+              brave-browser.desktop
+              firefox.desktop
+              google-chrome.desktop
+              firefox_firefox.desktop
+            Recommended applications:
+              brave-browser.desktop
+              firefox.desktop
+              google-chrome.desktop
+              firefox_firefox.desktop
+          err: ''
+  - id: test_set_handler_idempot_check
     input:
       handler: google-chrome.desktop
       mime_type: x-scheme-handler/http
     output:
       handler: google-chrome.desktop
       changed: false
+    flags:
+      check: true
     mocks:
       run_command:
         - command: [/testbin/gio, --version]