osbuild: setup isort autochecking

The `test-src` makefile target now also runs isort against all source
files and reports errors.

.git-blame-ignore-revs

@@ -0,0 +1 @@
+1be3f1bfb671fa6d59dcd2203f23e1625194574b

test/src/test_pylint.py

@@ -68,6 +68,19 @@ def test_mypy():
         pytest.fail("mypy issues detected")
 
 
+@pytest.mark.skipif(not test.TestBase.have_isort(), reason="isort not available")
+def test_isort(source_files):
+    #
+    # Run `isort` on all python sources. We simply use `find` to locate
+    # all `*.py` files, and then manually select the reverse-domain named
+    # modules we have.
+    #
+
+    r = subprocess.run(["isort", "-c"] + source_files, check=False)
+    if r.returncode != 0:
+        pytest.fail("isort issues detected")
+
+
 @pytest.mark.skipif(not test.TestBase.have_autopep8(), reason="autopep8 not available")
 def test_autopep8(source_files):
     r = subprocess.run(["autopep8-3", "--diff", "--exit-code"] + source_files, check=False)

test/test.py

@@ -203,6 +203,23 @@ class TestBase(unittest.TestCase):
 
         return r.returncode == 0 and "mypy" in r.stdout
 
+    def have_isort() -> bool:
+        """Check isort Availability
+
+        This checks whether `isort` is available in the current path and
+        can be called by this process.
+        """
+
+        try:
+            r = subprocess.run(
+                ["isort", "--version"],
+                encoding="utf-8", stdout=subprocess.PIPE, check=False
+            )
+        except FileNotFoundError:
+            return False
+
+        return r.returncode == 0 and "isort" in r.stdout
+
     @staticmethod
     def have_rpm_ostree() -> bool:
         """Check rpm-ostree Availability