Merge branch 'CLI_bug_fix' into master

* CLI_bug_fix:
  Move the latest validator CLI test to where it must go now.
  Simplify the schemas in the tests for CLI validator detection.
  add test case
  Delete the failed test case
  Fix the bug of processing arguments[validator] in parse_args

Author: Julian

jsonschema/cli.py

@@ -191,8 +191,6 @@ def _namedAnyWithDefault(name):
 
 def parse_args(args):
     arguments = vars(parser.parse_args(args=args or ["--help"]))
-    if arguments["validator"] is None:
-        arguments["validator"] = validator_for(arguments["schema"])
     if arguments["output"] != "plain" and arguments["error_format"]:
         raise parser.error(
             "--error-format can only be used with --output plain"
@@ -229,6 +227,9 @@ def run(arguments, stdout=sys.stdout, stderr=sys.stderr, stdin=sys.stdin):
     except _CannotLoadFile:
         return 1
 
+    if arguments["validator"] is None:
+        arguments["validator"] = validator_for(schema)
+
     try:
         arguments["validator"].check_schema(schema)
     except SchemaError as error:

jsonschema/tests/test_cli.py

@@ -8,7 +8,7 @@
 import subprocess
 import sys
 
-from jsonschema import Draft4Validator, __version__, cli
+from jsonschema import Draft4Validator, Draft7Validator, __version__, cli
 from jsonschema.exceptions import SchemaError, ValidationError
 from jsonschema.tests._helpers import captured_output
 from jsonschema.validators import _LATEST_VERSION, validate
@@ -675,17 +675,62 @@ def test_successful_validation_of_just_the_schema(self):
             stderr="",
         )
 
-    def test_successful_validation__of_just_the_schema_pretty_output(self):
+    def test_successful_validation_of_just_the_schema_pretty_output(self):
         self.assertOutputs(
             files=dict(some_schema="{}", some_instance="{}"),
             argv=["--output", "pretty", "-i", "some_instance", "some_schema"],
             stdout="===[SUCCESS]===(some_instance)===\n",
             stderr="",
         )
 
-    def test_real_validator(self):
+    def test_it_validates_using_the_latest_validator_when_unspecified(self):
+        # There isn't a better way now I can think of to ensure that the
+        # latest version was used, given that the call to validator_for
+        # is hidden inside the CLI, so guard that that's the case, and
+        # this test will have to be updated when versions change until
+        # we can think of a better way to ensure this behavior.
+        self.assertIs(Draft7Validator, _LATEST_VERSION)
+
+        self.assertOutputs(
+            files=dict(some_schema='{"const": "check"}', some_instance='"a"'),
+            argv=["-i", "some_instance", "some_schema"],
+            exit_code=1,
+            stdout="",
+            stderr="a: 'check' was expected\n",
+        )
+
+    def test_it_validates_using_draft7_when_specified(self):
+        """
+        Specifically, `const` validation applies for Draft 7.
+        """
+        schema = """
+            {
+                "$schema": "http://json-schema.org/draft-07/schema#",
+                "const": "check"
+            }
+        """
+        instance = '"foo"'
         self.assertOutputs(
-            files=dict(some_schema='{"minimum": 30}', some_instance="37"),
+            files=dict(some_schema=schema, some_instance=instance),
+            argv=["-i", "some_instance", "some_schema"],
+            exit_code=1,
+            stdout="",
+            stderr="foo: 'check' was expected\n",
+        )
+
+    def test_it_validates_using_draft4_when_specified(self):
+        """
+        Specifically, `const` validation *does not* apply for Draft 4.
+        """
+        schema = """
+            {
+                "$schema": "http://json-schema.org/draft-04/schema#",
+                "const": "check"
+            }
+            """
+        instance = '"foo"'
+        self.assertOutputs(
+            files=dict(some_schema=schema, some_instance=instance),
             argv=["-i", "some_instance", "some_schema"],
             stdout="",
             stderr="",
@@ -717,15 +762,6 @@ def test_find_validator_in_jsonschema(self):
         )
         self.assertIs(arguments["validator"], Draft4Validator)
 
-    def test_latest_validator_is_the_default(self):
-        arguments = cli.parse_args(
-            [
-                "--instance", "mem://some/instance",
-                "mem://some/schema",
-            ]
-        )
-        self.assertIs(arguments["validator"], _LATEST_VERSION)
-
     def test_unknown_output(self):
         # Avoid the help message on stdout
         with captured_output() as (stdout, stderr):