Protect against old jsonschema (eg 3.2.0) that lack string format con…

…straints

moo/jsonschema.py

@@ -6,10 +6,14 @@
 
 import jsonschema
 
-# without this, format="..." will be ignored.
-format_checker = jsonschema.Draft7Validator.FORMAT_CHECKER
-
-
+# Without this, format="..." will be ignored.
+# Older versions of jsonschema (eg 3.2.0) lack it.
+try:
+    format_checker = jsonschema.Draft7Validator.FORMAT_CHECKER
+except AttributeError:
+    import sys
+    sys.stderr.write("WARNING: your jsonschema is old.  string format constraints will be ignored")
+    format_checker = None
 
 def ref(oschema):
     '''

moo/ogen.py

@@ -10,9 +10,7 @@
 from moo.modutil import resolve, module_at
 from collections.abc import Mapping
 
-from jsonschema import validate as js_validate
-from jsonschema.exceptions import ValidationError
-from .jsonschema import format_checker
+from .jsonschema import validate, ValidationError
 
 class BaseType:
     pass
@@ -100,8 +98,7 @@ def wash_string(types, ost, *args, **kwds):
         schema["pattern"] = ost["pattern"]
 
     try:
-        js_validate(instance=val, schema=schema,
-                    format_checker=format_checker)
+        validate(val, schema)
     except ValidationError as verr:
         raise ValueError(f'illegal string format {name} value: {val}') from verr
     return val

moo/oschema.py

@@ -12,13 +12,7 @@
 
 
 import numpy
-import jsonschema
-
-
-def validate(value, schema):
-    jsonschema.validate(value, schema,
-                        format_checker=jsonschema.draft7_format_checker)
-    return value
+from .jsonschema import validate, ValidationError
 
 
 # this holds all known types

moo/otypes.py

@@ -9,6 +9,7 @@
 from importlib import import_module
 from moo.modutil import module_at
 from moo.io import load as load_file
+from .jsonschema import validate, ValidationError
 
 
 def get_deps(deps=None, **ost):
@@ -373,11 +374,8 @@ def update(self, val: str):
             schema["pattern"] = ost["pattern"]
         if ost["format"]:
             schema["format"] = ost["format"]
-        from jsonschema import validate as js_validate
-        from .jsonschema import format_checker
-        from jsonschema.exceptions import ValidationError
         try:
-            js_validate(instance=val, schema=schema,format_checker=format_checker)
+            validate(val, schema)
         except ValidationError as verr:
             raise ValueError(f'format mismatch for string {cname}') from verr
         self._value = val

test/test_moo_ogen.py

@@ -2,7 +2,7 @@
 import pytest
 import moo
 from moo.ogen import TypeBuilder
-
+from moo.jsonschema import format_checker
 
 def test_type_builder():
     sc = [
@@ -50,8 +50,9 @@ def test_type_builder():
         Age(Height(177.8))
 
     from a.b import Email
-    with pytest.raises(ValueError):
-        Email("not-an-email-address")
+    if format_checker:
+        with pytest.raises(ValueError):
+            Email("not-an-email-address")
 
     from a.b import Fruit
     assert "apple" == Fruit("apple").pod()

test/test_moo_otypes.py

@@ -5,7 +5,7 @@
 import os
 import moo
 import pytest
-
+from moo.jsonschema import format_checker
 
 def test_junk():
     'Test various stuff about moo.otypes'
@@ -57,13 +57,15 @@ def test_with_schema():
     Person = types['app.Person']
     Affiliation = types['app.Affiliation']
 
-    with pytest.raises(ValueError):
-        e = Email("this is not an email address and should fail")
-        print(f'EMAIL: {e} {repr(e)}')
+    if format_checker:
+        with pytest.raises(ValueError):
+            e = Email("this is not an email address and should fail")
+            print(f'EMAIL: {e} {repr(e)}')
 
     p = Person()
-    with pytest.raises(ValueError):
-        p.email = "this should fail"
+    if format_checker:
+        with pytest.raises(ValueError):
+            p.email = "this should fail"
     with pytest.raises(AttributeError):
         p.email
     p.email = "brett.viren@gmail.com"

test/test_validate.py

@@ -1,5 +1,6 @@
 import pytest
 
+from moo.jsonschema import format_checker
 from moo.ovalid import validate, ValidationError
 
 def test_regex():
@@ -18,12 +19,13 @@ def test_regex():
                                pattern = '[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}'))
 
     validate("127.0.0.1", dict(js, type="string", format="ipv4"))
-    with pytest.raises(ValidationError):
-        validate("& not @ ip", dict(js, type="string", format="ipv4"))
 
-    # https://github.com/python-jsonschema/jsonschema/issues/403
-    with pytest.raises(ValidationError):
-        validate("1;2;3#4", dict(js, type="string", format="email"))
+    if format_checker:
+        with pytest.raises(ValidationError):
+            validate("& not @ ip", dict(js, type="string", format="ipv4"))
+
+        with pytest.raises(ValidationError):
+            validate("1;2;3#4", dict(js, type="string", format="email"))
 
     with pytest.raises(ValidationError):
         validate(1234, dict(js, type="string"))