Automatically register the schema tester pytest plugin

CHANGES.rst

@@ -5,10 +5,14 @@
 
 - Overhaul packaging infrastructure. Remove use of ``astropy_helpers``. [#670]
 
+- Automatically register schema tester plugin. Do not enable schema tests by
+  default. Add configuration setting and command line option to enable schema
+  tests. [#676]
+
 2.3.4 (unreleased)
 ------------------
 
-- Fix bug in ``NDArrayType.__len__``.  It must be a method, not a 
+- Fix bug in ``NDArrayType.__len__``.  It must be a method, not a
   property. [#673]
 
 2.3.3 (2019-04-02)

asdf/extension.py

@@ -244,4 +244,10 @@ def reset(self):
         self._extension_list = None
         self._package_metadata = {}
 
+    def resolver(self, uri):
+        tag_mapping = self.extension_list.tag_mapping
+        url_mapping = self.extension_list.url_mapping
+        return url_mapping(tag_mapping(uri))
+
+
 default_extensions = _DefaultExtensions()

asdf/version.py

@@ -1,7 +1,7 @@
 from pkg_resources import get_distribution, DistributionNotFound
 
 try:
-    version = get_distribution(__package__).version
+    version = get_distribution('asdf').version
 except DistributionNotFound:
     # package is not installed
     version = "unknown"

conftest.py

@@ -25,7 +25,6 @@
 
 
 pytest_plugins = [
-    'asdf.tests.schema_tester',
     'astropy.tests.plugins.display'
 ]
 

docs/asdf/extensions.rst

@@ -722,25 +722,11 @@ Packages that provide their own schemas can test them using ASDF's
 Schemas are tested for overall validity, and any examples given within the
 schemas are also tested.
 
-The schema tester plugin is automatically made available when the ASDF package
-is installed. In order to enable testing, the following steps are required:
-
-1. Add `asdf.tests.schema_tester` to the list of pytest plugins in the
-   top-level `conftest.py` file for your package. If that file does not already
-   exist, creating a `conftest.py` file containing the following should be
-   sufficient (see `this
-   <https://docs.pytest.org/en/2.7.3/plugins.html?highlight=re>`_ for more
-   information on `conftest.py` files):
-
-.. code:: python
-
-    pytest_plugins = [
-        'asdf.tests.schema_tester'
-    ]
-
-2. Add the directory containing your schema files to the pytest section of your
-   project's `setup.cfg` file. If you do not already have such a file, creating
-   a `setup.cfg` with the following should be sufficient:
+The schema tester plugin is automatically registered when the ASDF package is
+installed. In order to enable testing, it is necessary to add the directory
+containing your schema files to the pytest section of your project's
+`setup.cfg` file. If you do not already have such a file, creating a
+`setup.cfg` with the following should be sufficient:
 
 .. code:: ini
 
@@ -752,8 +738,22 @@ package directory **when it is installed**. If this is different from the path
 in the source directory, then both paths can be used to facilitate in-place
 testing (see ASDF's own `setup.cfg` for an example of this).
 
+.. note::
+
+   Older versions of ASDF (prior to 2.4.0) required the plugin to be registered
+   in your project's `conftest.py` file. As of 2.4.0, the plugin is now
+   registered automatically and so this line should be removed from your
+   `conftest.py` file, unless you need to retain compatibility with older
+   versions of ASDF.
+
 The ``asdf_schema_skip_names`` configuration variable can be used to skip
 schema files that live within one of the ``asdf_schema_root`` directories but
 should not be tested. The names should be given as simple base file names
 (without directory paths or extensions). Again, see ASDF's own `setup.cfg` file
 for an example.
+
+The schema tests do **not** run by default. In order to enable the tests by
+default for your package, add ``asdf_schema_tests_enabled = true`` to the
+``[tool:pytest]`` section of your `setup.cfg` file. If you do not wish to
+enable the schema tests by default, you can add the ``--asdf-tests`` option to
+the ``pytest`` command line to enable tests on a per-run basis.

pytest_asdf/__init__.py

@@ -0,0 +1 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst

pytest_asdf/extension.py

@@ -0,0 +1,32 @@
+from asdf import extension
+from asdf.tests import CustomTestType
+
+
+class LabelMapperTestType(CustomTestType):
+    version = '1.0.0'
+    name = 'transform/label_mapper'
+
+
+class RegionsSelectorTestType(CustomTestType):
+    version = '1.0.0'
+    name = 'transform/regions_selector'
+
+
+class TestExtension(extension.BuiltinExtension):
+    """This class defines an extension that represents tags whose
+    implementations current reside in other repositories (such as GWCS) but
+    whose schemas are defined in ASDF. This provides a workaround for schema
+    validation testing since we want to pass without warnings, but the fact
+    that these tag classes are not defined within ASDF means that warnings
+    occur unless this extension is used. Eventually these schemas may be moved
+    out of ASDF and into other repositories, or ASDF will potentially provide
+    abstract base classes for the tag implementations.
+    """
+    @property
+    def types(self):
+        return [LabelMapperTestType, RegionsSelectorTestType]
+
+    @property
+    def tag_mapping(self):
+        return [('tag:stsci.edu:asdf',
+                 'http://stsci.edu/schemas/asdf{tag_suffix}')]

asdf/tests/schema_tester.py → pytest_asdf/plugin.py

@@ -10,50 +10,7 @@
 
 import numpy as np
 
-import asdf
-from asdf import AsdfFile
-from asdf import block
-from asdf import schema
-from asdf import extension
-from asdf import treeutil
-from asdf import util
-from asdf import versioning
-from . import helpers, CustomTestType
-
-_ctx = AsdfFile()
-_resolver = _ctx.resolver
-
-
-class LabelMapperTestType(CustomTestType):
-    version = '1.0.0'
-    name = 'transform/label_mapper'
-
-
-class RegionsSelectorTestType(CustomTestType):
-    version = '1.0.0'
-    name = 'transform/regions_selector'
-
-
-class TestExtension(extension.BuiltinExtension):
-    """This class defines an extension that represents tags whose
-    implementations current reside in other repositories (such as GWCS) but
-    whose schemas are defined in ASDF. This provides a workaround for schema
-    validation testing since we want to pass without warnings, but the fact
-    that these tag classes are not defined within ASDF means that warnings
-    occur unless this extension is used. Eventually these schemas may be moved
-    out of ASDF and into other repositories, or ASDF will potentially provide
-    abstract base classes for the tag implementations.
-    """
-    @property
-    def types(self):
-        return [LabelMapperTestType, RegionsSelectorTestType]
-
-    @property
-    def tag_mapping(self):
-        return [('tag:stsci.edu:asdf',
-                 'http://stsci.edu/schemas/asdf{tag_suffix}')]
-
-
+# Avoid all imports of asdf at this level in order to avoid circular imports
 
 
 def pytest_addoption(parser):
@@ -64,6 +21,11 @@ def pytest_addoption(parser):
     parser.addini(
         "asdf_schema_skip_examples",
         "Base names of schemas whose examples should not be tested")
+    parser.addini(
+        "asdf_schema_tests_enabled",
+        "Controls whether schema tests are enabled by default")
+    parser.addoption('--asdf-tests', action='store_true',
+        help='Enable ASDF schema tests')
 
 
 class AsdfSchemaFile(pytest.File):
@@ -80,6 +42,8 @@ def collect(self):
 
     def find_examples_in_schema(self):
         """Returns generator for all examples in schema at given path"""
+        from asdf import treeutil
+
         with open(str(self.fspath), 'rb') as fd:
             schema_tree = yaml.safe_load(fd)
 
@@ -97,9 +61,13 @@ def __init__(self, schema_path, parent):
         self.schema_path = schema_path
 
     def runtest(self):
+        from asdf import schema
+        from asdf.extension import default_extensions
+
         # Make sure that each schema itself is valid.
         schema_tree = schema.load_schema(
-            self.schema_path, resolver=_resolver, resolve_references=True)
+            self.schema_path, resolver=default_extensions.resolver,
+            resolve_references=True)
         schema.check_schema(schema_tree)
 
 
@@ -117,6 +85,7 @@ def should_skip(name, version):
     return False
 
 def parse_schema_filename(filename):
+    from asdf import versioning
     components = filename[filename.find('schemas') + 1:].split(os.path.sep)
     tag = 'tag:{}:{}'.format(components[1], '/'.join(components[2:]))
     name, version = versioning.split_tag_version(tag.replace('.yaml', ''))
@@ -131,6 +100,7 @@ def __init__(self, schema_path, parent, example):
         self.example = example
 
     def _find_standard_version(self, name, version):
+        from asdf import versioning
         for sv in versioning.supported_versions:
             map_version = versioning.get_version_map(sv)['tags'].get(name)
             if map_version is not None and version == map_version:
@@ -139,6 +109,9 @@ def _find_standard_version(self, name, version):
         return versioning.default_version
 
     def runtest(self):
+        from asdf import AsdfFile, block, util
+        from asdf.tests import helpers
+        from .extension import TestExtension
 
         name, version = parse_schema_filename(self.filename)
         if should_skip(name, version):
@@ -189,6 +162,10 @@ def runtest(self):
 
 
 def pytest_collect_file(path, parent):
+    if not (parent.config.getini('asdf_schema_tests_enabled') or
+            parent.config.getoption('asdf_tests')):
+        return
+
     schema_roots = parent.config.getini('asdf_schema_root').split()
     if not schema_roots:
         return

setup.cfg

@@ -25,6 +25,7 @@ packages =
     asdf
     asdf.schemas
     asdf.reference_files
+    pytest_asdf
 package_dir =
     asdf.schemas = asdf-standard/schemas
     asdf.reference_files = asdf-standard/reference_files
@@ -58,6 +59,8 @@ console_scripts =
     asdftool = asdf.commands.main:main
 asdf_extensions =
     builtin = asdf.extension:BuiltinExtension
+pytest11 =
+    asdf_schema_tester = pytest_asdf.plugin
 
 [build_sphinx]
 source-dir = docs
@@ -81,6 +84,8 @@ text_file_format = rst
 asdf_schema_root = asdf-standard/schemas asdf/schemas
 asdf_schema_skip_names = asdf-schema-1.0.0 draft-01
 asdf_schema_skip_examples = domain-1.0.0 frame-1.0.0 frame-1.1.0
+# Enable the schema tests by default
+asdf_schema_tests_enabled = true
 addopts = --doctest-rst
 
 [flake8]