Prevent tests from using 'should' in sanity check.

It makes descriptions longer (which we independently check for) but also
is stylistically a bit awkward.

https://jml.io/pages/test-docstrings.html is a good post on the subject,
with a sort of algorithm for removing this and related words.

Fix a first file (anchor) where descriptions are shortened and clarified
a bit.

Further files will be fixed in successive commits.

Author: Julian

bin/jsonschema_suite

@@ -160,6 +160,32 @@ class SanityTests(unittest.TestCase):
                 )
         print(f"Found {count} test cases.")
 
+    def test_descriptions_do_not_use_modal_verbs(self):
+        """
+        Instead of saying "test that X frobs" or "X should frob" use "X frobs".
+
+        See e.g. https://jml.io/pages/test-docstrings.html
+
+        This test isn't comprehensive (it doesn't catch all the extra
+        verbiage there), but it's just to catch whatever it manages to
+        cover.
+        """
+
+        message = (
+            "In descriptions, don't say 'Test that X frobs' or 'X should "
+            "frob' or 'X should be valid'. Just say 'X frobs' or 'X is "
+            "valid'. It's shorter, and the test suite is entirely about "
+            "what *should* be already. "
+            "See https://jml.io/pages/test-docstrings.html for help."
+        )
+        for test in tests(self.test_files):
+            with self.subTest(description=test["description"]):
+                self.assertNotRegex(
+                    test["description"],
+                    r"\bshould\b",
+                    message,
+                )
+
     @unittest.skipIf(jsonschema is None, "Validation library not present!")
     def test_all_schemas_are_valid(self):
         """

tests/draft-next/anchor.json

@@ -159,12 +159,12 @@
         },
         "tests": [
             {
-                "description": "$ref should resolve to /$defs/A/allOf/1",
+                "description": "$ref resolves to /$defs/A/allOf/1",
                 "data": "a",
                 "valid": true
             },
             {
-                "description": "$ref should not resolve to /$defs/A/allOf/0",
+                "description": "$ref does not resolve to /$defs/A/allOf/0",
                 "data": 1,
                 "valid": false
             }

tests/draft2019-09/anchor.json

@@ -159,12 +159,12 @@
         },
         "tests": [
             {
-                "description": "$ref should resolve to /$defs/A/allOf/1",
+                "description": "$ref resolves to /$defs/A/allOf/1",
                 "data": "a",
                 "valid": true
             },
             {
-                "description": "$ref should not resolve to /$defs/A/allOf/0",
+                "description": "$ref does not resolve to /$defs/A/allOf/0",
                 "data": 1,
                 "valid": false
             }

tests/draft2020-12/anchor.json

@@ -159,12 +159,12 @@
         },
         "tests": [
             {
-                "description": "$ref should resolve to /$defs/A/allOf/1",
+                "description": "$ref resolves to /$defs/A/allOf/1",
                 "data": "a",
                 "valid": true
             },
             {
-                "description": "$ref should not resolve to /$defs/A/allOf/0",
+                "description": "$ref does not resolve to /$defs/A/allOf/0",
                 "data": 1,
                 "valid": false
             }