Fix --set-schema (which was treating cases as dicts).

bowtie/_cli.py

@@ -332,8 +332,8 @@ async def _run(
             seq = 0
             should_stop = False
             for seq, case, case_reporter in sequenced(cases, reporter):
-                if set_schema and not isinstance(case["schema"], bool):
-                    case["schema"]["$schema"] = dialect
+                if set_schema and not isinstance(case.schema, bool):
+                    case.schema["$schema"] = dialect
 
                 responses = [
                     each.run_case(seq=seq, case=case) for each in runners

tests/test_integration.py

@@ -138,6 +138,19 @@ async def test_it_runs_tests_from_a_file(tmp_path, envsonschema):
     assert returncode == 0
 
 
+@pytest.mark.asyncio
+async def test_set_schema_sets_a_dialect_explicitly(envsonschema):
+    async with bowtie("-i", envsonschema, "--set-schema") as send:
+        returncode, results, _, _, stderr = await send(
+            """
+            {"description": "a test case", "schema": {}, "tests": [{"description": "valid:1", "instance": {}}] }
+            """,  # noqa: E501
+        )
+
+    assert results == [[{"valid": True}]], stderr
+    assert returncode == 0
+
+
 @pytest.mark.asyncio
 async def test_no_tests_run(envsonschema):
     async with bowtie("-i", envsonschema) as send: