From f13195f874a4ae5c2ddcf889ceea8f1e2e8fa84b Mon Sep 17 00:00:00 2001
From: willson-chen <willson.chenwx@gmail.com>
Date: Thu, 20 Aug 2020 16:04:51 +0800
Subject: [PATCH 1/3] Fix the bug of processing arguments[validator] in
 parse_args

---
 jsonschema/cli.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/jsonschema/cli.py b/jsonschema/cli.py
index 4c2bb4f20..713193979 100644
--- a/jsonschema/cli.py
+++ b/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:

From 5680761abfd3462dcf2fe5de442d129c1350c790 Mon Sep 17 00:00:00 2001
From: willson-chen <willson.chenwx@gmail.com>
Date: Thu, 20 Aug 2020 20:26:16 +0800
Subject: [PATCH 2/3] Delete the failed test case

---
 jsonschema/tests/test_cli.py | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/jsonschema/tests/test_cli.py b/jsonschema/tests/test_cli.py
index 7ca32fc73..441ad6fa8 100644
--- a/jsonschema/tests/test_cli.py
+++ b/jsonschema/tests/test_cli.py
@@ -11,7 +11,7 @@
 from jsonschema import Draft4Validator, __version__, cli
 from jsonschema.exceptions import SchemaError, ValidationError
 from jsonschema.tests._helpers import captured_output
-from jsonschema.validators import _LATEST_VERSION, validate
+from jsonschema.validators import validate
 
 
 def fake_validator(*errors):
@@ -717,15 +717,6 @@ 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):

From dc509218ffd4e4fabb35acd27cf3fb8678be2080 Mon Sep 17 00:00:00 2001
From: willson-chen <willson.chenwx@gmail.com>
Date: Mon, 24 Aug 2020 14:09:10 +0800
Subject: [PATCH 3/3] add test case

---
 jsonschema/tests/test_cli.py | 53 +++++++++++++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 1 deletion(-)

diff --git a/jsonschema/tests/test_cli.py b/jsonschema/tests/test_cli.py
index 441ad6fa8..d0ca811d3 100644
--- a/jsonschema/tests/test_cli.py
+++ b/jsonschema/tests/test_cli.py
@@ -11,7 +11,7 @@
 from jsonschema import Draft4Validator, __version__, cli
 from jsonschema.exceptions import SchemaError, ValidationError
 from jsonschema.tests._helpers import captured_output
-from jsonschema.validators import validate
+from jsonschema.validators import _LATEST_VERSION, validate, validator_for
 
 
 def fake_validator(*errors):
@@ -691,6 +691,47 @@ def test_real_validator(self):
             stderr="",
         )
 
+    def test_draft07_check_const(self):
+        schema = """
+                {
+                    "$schema": "http://json-schema.org/draft-07/schema#",
+                    "properties": {
+                        "value": {
+                            "type": "string",
+                            "const": "check"
+                        }
+                    }
+                }
+                """
+        instance = """{"value": "2"}"""
+        self.assertOutputs(
+            files=dict(some_schema=schema, some_instance=instance),
+            argv=["-i", "some_instance", "some_schema"],
+            exit_code=1,
+            stdout="",
+            stderr="2: 'check' was expected\n",
+        )
+
+    def test_draft04_not_check_const(self):
+        schema = """
+                {
+                    "$schema": "http://json-schema.org/draft-04/schema#",
+                    "properties": {
+                        "value": {
+                            "type": "string",
+                            "const": "check"
+                        }
+                    }
+                }
+                """
+        instance = """{"value": "2"}"""
+        self.assertOutputs(
+            files=dict(some_schema=schema, some_instance=instance),
+            argv=["-i", "some_instance", "some_schema"],
+            stdout="",
+            stderr="",
+        )
+
 
 class TestParser(TestCase):
 
@@ -717,6 +758,16 @@ 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",
+            ]
+        )
+        arguments["validator"] = validator_for(arguments["schema"])
+        self.assertIs(arguments["validator"], _LATEST_VERSION)
+
     def test_unknown_output(self):
         # Avoid the help message on stdout
         with captured_output() as (stdout, stderr):