test: add unit tests for tools.file_import and tools.get_experiment

Signed-off-by: Etienne Wodey <wodey@iqo.uni-hannover.de>

artiq/test/test_tools.py

@@ -0,0 +1,118 @@
+from contextlib import contextmanager
+import unittest
+from pathlib import Path
+import tempfile
+
+from artiq import tools
+
+
+# Helper to create temporary modules
+# Very simplified version of CPython's
+# Lib/test/test_importlib/util.py:create_modules
+@contextmanager
+def create_modules(*names):
+    mapping = {}
+    with tempfile.TemporaryDirectory() as temp_dir:
+        mapping[".root"] = Path(temp_dir)
+
+        for name in names:
+            file_path = Path(temp_dir) / f"{name}.py"
+            with file_path.open("w") as fp:
+                print(f"_MODULE_NAME = {name!r}", file=fp)
+            mapping[name] = file_path
+
+        yield mapping
+
+
+MODNAME = "modname"
+
+
+class TestFileImport(unittest.TestCase):
+    def test_import_and_prefix_is_present(self):
+        prefix = "prefix_"
+        with create_modules(MODNAME) as mods:
+            mod = tools.file_import(str(mods[MODNAME]), prefix=prefix)
+            self.assertEqual(prefix + MODNAME, mod.__name__)
+
+    def test_can_import_from_same_level(self):
+        m1_name, m2_name = "mod1", "mod2"
+        with create_modules(m1_name, m2_name) as mods:
+            with mods[m2_name].open("a") as fp:
+                print(f"from {m1_name} import _MODULE_NAME as _M1_NAME", file=fp)
+
+            mod1 = tools.file_import(str(mods[m1_name]))
+            mod2 = tools.file_import(str(mods[m2_name]))
+
+            self.assertEqual(mod2._M1_NAME, mod1._MODULE_NAME)
+
+
+class TestGetExperiment(unittest.TestCase):
+    def test_fail_no_experiments(self):
+        with create_modules(MODNAME) as mods:
+            mod = tools.file_import(str(mods[MODNAME]))
+            with self.assertRaises(ValueError):
+                tools.get_experiment(mod)
+
+    def test_fail_hidden_experiment(self):
+        with create_modules(MODNAME) as mods:
+            with mods[MODNAME].open("a") as fp:
+                print(
+                    """
+from artiq.experiment import *
+
+class _Exp1(EnvExperiment):
+    pass
+                """,
+                    file=fp,
+                )
+
+            mod = tools.file_import(str(mods[MODNAME]))
+            with self.assertRaises(ValueError):
+                tools.get_experiment(mod)
+
+    def test_multiple_experiments(self):
+        with create_modules(MODNAME) as mods:
+            with mods[MODNAME].open("a") as fp:
+                print(
+                    """
+from artiq.experiment import *
+
+class Exp1(EnvExperiment):
+    pass
+
+class Exp2(EnvExperiment):
+    pass
+                """,
+                    file=fp,
+                )
+
+            mod = tools.file_import(str(mods[MODNAME]))
+
+            # by class name
+            self.assertIs(mod.Exp1, tools.get_experiment(mod, "Exp1"))
+            self.assertIs(mod.Exp2, tools.get_experiment(mod, "Exp2"))
+
+            # by elimination should fail
+            with self.assertRaises(ValueError):
+                tools.get_experiment(mod)
+
+    def test_single_experiment(self):
+        with create_modules(MODNAME) as mods:
+            with mods[MODNAME].open("a") as fp:
+                print(
+                    """
+from artiq.experiment import *
+
+class Exp1(EnvExperiment):
+    pass
+                """,
+                    file=fp,
+                )
+
+            mod = tools.file_import(str(mods[MODNAME]))
+
+            # by class name
+            self.assertIs(mod.Exp1, tools.get_experiment(mod, "Exp1"))
+
+            # by elimination
+            self.assertIs(mod.Exp1, tools.get_experiment(mod))