test/builder: add unit test skeleton

Add the skeleton to run builder plugin unit tests and check that
exceptions are throw for unknown build target and unsupported
architectures.

test/unit/test_builder.py

@@ -0,0 +1,86 @@
+#
+# koji hub plugin unit tests
+#
+
+
+import unittest
+import os
+import imp
+from flexmock import flexmock
+
+import koji
+
+
+class TestHubPlugin(unittest.TestCase):
+    def setUp(self):
+        """Loads the plugin to self.plugin"""
+        root = os.getenv("GITHUB_WORKSPACE", os.getcwd())
+
+        haystack = os.path.join(root, "plugins", "builder")
+
+        fp, path, desc = imp.find_module("osbuild", [haystack])
+        try:
+            self.plugin = imp.load_module("osbuild", fp, path, desc)
+        finally:
+            fp.close()
+
+    def test_unknown_build_target(self):
+        session = flexmock()
+
+        session.should_receive("getBuildTarget") \
+            .with_args("target", strict=True) \
+            .and_return(None)
+
+        options = flexmock(allowed_scms='pkg.osbuild.org:/*:no',
+                           workdir="/tmp")
+        handler = self.plugin.OSBuildImage(1,
+                                           "osbuildImage",
+                                           "params",
+                                           session,
+                                           options)
+
+        args = ["name", "version", "distro",
+                ["image_type"],
+                "target",
+                ["arches"],
+                {}]
+
+        with self.assertRaises(koji.BuildError):
+            handler.handler(*args)
+
+    def test_unsupported_architecture(self):
+        session = flexmock()
+
+        build_target = {
+            "build_tag": "fedora-build",
+            "name": "fedora-candidate",
+            "dest_tag_name": "fedora-updates"
+        }
+
+        session.should_receive("getBuildTarget") \
+               .with_args("fedora-candidate", strict=True) \
+               .and_return(build_target) \
+               .once()
+
+        session.should_receive('getBuildConfig') \
+               .with_args(build_target["build_tag"]) \
+               .and_return({"arches": "x86_64"})
+
+        options = flexmock(allowed_scms='pkg.osbuild.org:/*:no',
+                           workdir="/tmp")
+
+        handler = self.plugin.OSBuildImage(1,
+                                           "osbuildImage",
+                                           "params",
+                                           session,
+                                           options)
+
+        args = ["name", "version", "distro",
+                ["image_type"],
+                "fedora-candidate",
+                ["s390x"],
+                {}]
+
+        with self.assertRaises(koji.BuildError) as err:
+            handler.handler(*args)
+            self.assertTrue(str(err).startswith("Unsupported"))