Streamlines imports and app start

tests/unit/test_cli_lazy_imports.py

@@ -0,0 +1,104 @@
+from __future__ import annotations
+
+import json
+from pathlib import Path
+import subprocess
+import sys
+import textwrap
+import unittest
+
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+SRC_ROOT = REPO_ROOT / "src"
+HEAVY_MODULES = [
+    "ffx.configuration_controller",
+    "ffx.database",
+    "ffx.ffx_app",
+    "ffx.ffx_controller",
+    "ffx.file_properties",
+    "ffx.tmdb_controller",
+]
+
+
+class CliLazyImportTests(unittest.TestCase):
+    def run_python(self, code: str) -> dict:
+        completed = subprocess.run(
+            [sys.executable, "-c", code],
+            capture_output=True,
+            cwd=REPO_ROOT,
+            text=True,
+        )
+        if completed.returncode != 0:
+            self.fail(
+                "Python helper failed\n"
+                f"STDOUT:\n{completed.stdout}\n"
+                f"STDERR:\n{completed.stderr}"
+            )
+        return json.loads(completed.stdout)
+
+    def test_importing_cli_keeps_runtime_modules_unloaded(self):
+        result = self.run_python(
+            textwrap.dedent(
+                f"""
+                import json
+                import sys
+
+                sys.path.insert(0, {str(SRC_ROOT)!r})
+
+                import ffx.cli
+
+                print(json.dumps({{
+                    "modules": {{
+                        module_name: module_name in sys.modules
+                        for module_name in {HEAVY_MODULES!r}
+                    }},
+                }}))
+                """
+            )
+        )
+
+        self.assertTrue(
+            all(not is_loaded for is_loaded in result["modules"].values()),
+            result["modules"],
+        )
+
+    def test_lightweight_configure_workstation_command_stays_light(self):
+        result = self.run_python(
+            textwrap.dedent(
+                f"""
+                import json
+                import sys
+                from click.testing import CliRunner
+
+                sys.path.insert(0, {str(SRC_ROOT)!r})
+
+                import ffx.cli
+
+                runner = CliRunner()
+                invoke_result = runner.invoke(
+                    ffx.cli.ffx,
+                    ["--dry-run", "configure_workstation", "--check"],
+                )
+                if invoke_result.exit_code != 0:
+                    raise SystemExit(invoke_result.output)
+
+                print(json.dumps({{
+                    "output": invoke_result.output,
+                    "modules": {{
+                        module_name: module_name in sys.modules
+                        for module_name in {HEAVY_MODULES!r}
+                    }},
+                }}))
+                """
+            )
+        )
+
+        self.assertIn("configure_workstation.sh --check", result["output"])
+        self.assertTrue(
+            all(not is_loaded for is_loaded in result["modules"].values()),
+            result["modules"],
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()