Address grain issue and add test

salt/grains/core.py

@@ -1327,14 +1327,18 @@ def _windows_os_release_grain(caption, product_type):
     version = "Unknown"
     release = ""
     if "Server" in caption:
-        for item in caption.split(" "):
-            # If it's all digits, then it's version
-            if re.match(r"\d+", item):
-                version = item
-            # If it starts with R and then numbers, it's the release
-            # ie: R2
-            if re.match(r"^R\d+$", item):
-                release = item
+        # Edge case here to handle MS Product that doesn't contain a year
+        if re.match(r"^Microsoft Hyper-V Server$", caption):
+            version = "2019"
+        else:
+            for item in caption.split(" "):
+                # If it's all digits, then it's version
+                if re.match(r"\d+", item):
+                    version = item
+                # If it starts with R and then numbers, it's the release
+                # ie: R2
+                if re.match(r"^R\d+$", item):
+                    release = item
         os_release = "{0}Server{1}".format(version, release)
     else:
         for item in caption.split(" "):

tests/unit/grains/test_core.py

@@ -869,6 +869,12 @@ class CoreGrainsTestCase(TestCase, LoaderModuleMockMixin):
             version = core._windows_os_release_grain(caption, 1)
             self.assertEqual(version, "7")
 
+        # Microsoft Hyper-V Server 2019
+        # Issue https://github.com/saltstack/salt/issue/55212
+        caption = "Microsoft Hyper-V Server"
+        version = core._windows_os_release_grain(caption, 1)
+        self.assertEqual(version, "2019Server")
+
     @skipIf(not salt.utils.platform.is_linux(), "System is not Linux")
     def test_linux_memdata(self):
         """