And deprecate importing ErrorTree from jsonschema.validators.

2 files changed, 29 insertions, 10 deletions

diff --git a/jsonschema/tests/test_deprecations.py b/jsonschema/tests/test_deprecations.py
index ff1e316..7d51a41 100644
--- a/jsonschema/tests/test_deprecations.py
+++ b/jsonschema/tests/test_deprecations.py
@@ -1,7 +1,5 @@
 from unittest import TestCase
 
-import jsonschema
-
 
 class TestDeprecations(TestCase):
     def test_jsonschema_version(self):
@@ -10,10 +8,25 @@ class TestDeprecations(TestCase):
         """
 
         with self.assertWarns(DeprecationWarning) as w:
-            jsonschema.__version__
+            from jsonschema import __version__
 
         self.assertTrue(
             str(w.warning).startswith(
                 "Accessing jsonschema.__version__ is deprecated",
             ),
         )
+
+    def test_jsonschema_validators_ErrorTree(self):
+        """
+        As of v4.0.0, importing ErrorTree from jsonschema.validators is
+        deprecated in favor of doing so from jsonschema.exceptions.
+        """
+
+        with self.assertWarns(DeprecationWarning) as w:
+            from jsonschema.validators import ErrorTree
+
+        self.assertTrue(
+            str(w.warning).startswith(
+                "Importing ErrorTree from jsonschema.validators is deprecated",
+            ),
+        )
diff --git a/jsonschema/validators.py b/jsonschema/validators.py
index e0e2f8d..0314559 100644
--- a/jsonschema/validators.py
+++ b/jsonschema/validators.py
@@ -8,6 +8,7 @@ from urllib.request import urlopen
 from warnings import warn
 import contextlib
 import json
+import warnings
 
 from jsonschema import (
     _legacy_validators,
@@ -16,19 +17,24 @@ from jsonschema import (
     _validators,
     exceptions,
 )
-# Sigh. https://gitlab.com/pycqa/flake8/issues/280
-#       https://github.com/pyga/ebb-lint/issues/7
-# Imported for backwards compatibility.
-from jsonschema.exceptions import ErrorTree
-
-ErrorTree
-
 
 validators = {}
 meta_schemas = _utils.URIDict()
 _VOCABULARIES = _utils.URIDict()
 
 
+def __getattr__(name):
+    if name == "ErrorTree":
+        warnings.warn(
+            "Importing ErrorTree from jsonschema.validators is deprecated. "
+            "Instead import it from jsonschema.exceptions.",
+            DeprecationWarning,
+        )
+        from jsonschema.exceptions import ErrorTree
+        return ErrorTree
+    raise AttributeError(f"module {__name__} has no attribute {name}")
+
+
 def validates(version):
     """
     Register the decorated validator for a ``version`` of the specification.