lib.types: Add parentheses where description is ambiguous

lib/tests/misc.nix

@@ -1206,4 +1206,57 @@ runTests {
     expr = strings.levenshteinAtMost 3 "hello" "Holla";
     expected = true;
   };
+
+  testTypeDescriptionInt = {
+    expr = (with types; int).description;
+    expected = "signed integer";
+  };
+  testTypeDescriptionListOfInt = {
+    expr = (with types; listOf int).description;
+    expected = "list of signed integer";
+  };
+  testTypeDescriptionListOfListOfInt = {
+    expr = (with types; listOf (listOf int)).description;
+    expected = "list of list of signed integer";
+  };
+  testTypeDescriptionListOfEitherStrOrBool = {
+    expr = (with types; listOf (either str bool)).description;
+    expected = "list of (string or boolean)";
+  };
+  testTypeDescriptionEitherListOfStrOrBool = {
+    expr = (with types; either (listOf bool) str).description;
+    expected = "(list of boolean) or string";
+  };
+  testTypeDescriptionEitherStrOrListOfBool = {
+    expr = (with types; either str (listOf bool)).description;
+    expected = "string or list of boolean";
+  };
+  testTypeDescriptionOneOfListOfStrOrBool = {
+    expr = (with types; oneOf [ (listOf bool) str ]).description;
+    expected = "(list of boolean) or string";
+  };
+  testTypeDescriptionOneOfListOfStrOrBoolOrNumber = {
+    expr = (with types; oneOf [ (listOf bool) str number ]).description;
+    expected = "(list of boolean) or string or signed integer or floating point number";
+  };
+  testTypeDescriptionEitherListOfBoolOrEitherStringOrNumber = {
+    expr = (with types; either (listOf bool) (either str number)).description;
+    expected = "(list of boolean) or string or signed integer or floating point number";
+  };
+  testTypeDescriptionEitherEitherListOfBoolOrStringOrNumber = {
+    expr = (with types; either (either (listOf bool) str) number).description;
+    expected = "(list of boolean) or string or signed integer or floating point number";
+  };
+  testTypeDescriptionEitherNullOrBoolOrString = {
+    expr = (with types; either (nullOr bool) str).description;
+    expected = "null or boolean or string";
+  };
+  testTypeDescriptionEitherListOfEitherBoolOrStrOrInt = {
+    expr = (with types; either (listOf (either bool str)) int).description;
+    expected = "(list of (boolean or string)) or signed integer";
+  };
+  testTypeDescriptionEitherIntOrListOrEitherBoolOrStr = {
+    expr = (with types; either int (listOf (either bool str))).description;
+    expected = "signed integer or list of (boolean or string)";
+  };
 }