Add test cases from OpenAPI specs examples

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "tests/OpenAPI-Specification"]
+	path = tests/OpenAPI-Specification
+	url = https://github.com/OAI/OpenAPI-Specification.git

tests/test_specs.py

@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+"""Test OpenAPI specs examples."""
+
+__author__ = 'Jens Finkhaeuser'
+__copyright__ = 'Copyright (c) 2018 Jens Finkhaeuser'
+__license__ = 'MIT +no-false-attribs'
+__all__ = ()
+
+import pytest
+
+from prance import ResolvingParser
+from prance import SwaggerValidationError
+from prance.util.fs import FileNotFoundError
+
+def make_name(path, parser, backend, version, file_format, entry):
+  import os.path
+  basename = os.path.splitext(entry)[0]
+  basename = basename.replace('-', '_')
+  version = version.replace('.', '')
+  backend = backend.replace('-', '_')
+
+  name = '_'.join(['test', parser, backend, version, file_format, basename])
+  return name
+
+# Generate test cases at import.
+# One case per combination of:
+# - parser (base, resolving)
+# - validation backend (flex, swagger-spec-validator)
+# - spec version (v2.0 only so far)
+# - file format
+# - file
+# That gives >50 test cases
+import os, os.path
+base = 'tests/OpenAPI-Specification/examples'
+
+for parser in ('BaseParser', 'ResolvingParser'):
+  for backend in ('flex', 'swagger-spec-validator'):
+    for version in os.listdir(base):
+      version_dir = os.path.join(base, version)
+      for file_format in os.listdir(version_dir):
+        format_dir = os.path.join(version_dir, file_format)
+        if not os.path.isdir(format_dir):
+          continue  # effectively skips v3.0 for now
+
+        for entry in os.listdir(format_dir):
+          full = os.path.join(format_dir, entry)
+          testcase_name = None
+          if os.path.isfile(full):
+            testcase_name = make_name(full, parser, backend, version, file_format, entry)
+          elif os.path.isdir(full):
+            if parser == 'BaseParser':
+              continue  # skip separate files for the BaseParser
+            full = os.path.join(full, 'spec/swagger.%s' % (file_format))
+            if os.path.isfile(full):
+              testcase_name = make_name(full, parser, backend, version, file_format, entry)
+          full = os.path.abspath(full)
+
+          if testcase_name:
+            dirname = os.path.dirname(full)
+            code = """
+def %s():
+  import os
+  cur = os.getcwd()
+
+  os.chdir('%s')
+
+  from prance import %s
+  try:
+    parser = %s('%s', backend = '%s')
+  finally:
+    os.chdir(cur)
+""" % (testcase_name, dirname, parser, parser, full, backend)
+            print(code)
+            exec(code, globals(), globals())