update CONTRIBUTING.md to explain compiling and adding snapshot tests

CONTRIBUTING.md

@@ -79,10 +79,12 @@ How do I know what kind of test(s) to write?
 
 For each new detector, at least one regression tests must be present.
 
-1. Create a test in `tests/e2e/detectors`
-2. Update `ALL_TEST` in `tests/e2e/detectors/test_detectors.py`
-3. Run `python tests/e2e/detectors/test_detectors.py --generate`. This will generate the json artifacts in `tests/expected_json`. Add the generated files to git. If updating an existing detector, identify the respective json artifacts and then delete them, or run `python ./tests/test_detectors.py --overwrite` instead.
-4. Run `pytest tests/e2e/detectors/test_detectors.py` and check that everything worked.
+1. Create a folder in `tests/e2e/detectors/test_data` with the detector's argument name. 
+2. Create a test contract in `tests/e2e/detectors/test_data/<detector_name>/`.
+3. Update `ALL_TEST` in `tests/e2e/detectors/test_detectors.py`
+4. Run `python tests/e2e/detectors/test_detectors.py --compile` to create a zip file of the compilation artifacts. 
+5. `pytest tests/e2e/detectors/test_detectors.py --insta update-new`. This will generate a snapshot of the detector output in `tests/e2e/detectors/snapshots/`. If updating an existing detector, run `pytest tests/e2e/detectors/test_detectors.py --insta review` and accept or reject the updates. 
+6. Run `pytest tests/e2e/detectors/test_detectors.py` to ensure everything worked. Then, add and commit the files to git.
 
 > ##### Helpful commands for detector tests
 >

tests/e2e/detectors/test_detectors.py

@@ -33,7 +33,6 @@ class Test:  # pylint: disable=too-few-public-methods
         """
         self.detector = detector
         self.test_file = test_file
-        self.expected_result = test_file + "." + solc_ver + "." + detector.__name__ + ".json"
         self.solc_ver = solc_ver
         if additional_files is None:
             self.additional_files = []
@@ -44,6 +43,11 @@ class Test:  # pylint: disable=too-few-public-methods
 def set_solc(test_item: Test):  # pylint: disable=too-many-lines
     # hacky hack hack to pick the solc version we want
     env = dict(os.environ)
+    from solc_select import solc_select
+
+    if not solc_select.artifact_path(test_item.solc_ver).exists():
+        print("Installing solc version", test_item.solc_ver)
+        solc_select.install_artifacts([test_item.solc_ver])
     env["SOLC_VERSION"] = test_item.solc_ver
     os.environ.clear()
     os.environ.update(env)
@@ -1638,26 +1642,12 @@ ALL_TEST_OBJECTS = [
     ),
 ]
 
-
-def get_all_tests() -> List[Test]:
-    # installed_solcs = set(get_installed_solc_versions())
-    # required_solcs = {test.solc_ver for test in ALL_TEST_OBJECTS}
-    # missing_solcs = list(required_solcs - installed_solcs)
-    # if missing_solcs:
-    #     install_solc_versions(missing_solcs)
-
-    return ALL_TEST_OBJECTS
-
-
-ALL_TESTS = get_all_tests()
-
 GENERIC_PATH = "/GENERIC_PATH"
 
 TEST_DATA_DIR = Path(__file__).resolve().parent / "test_data"
 
-
 # pylint: disable=too-many-locals
-@pytest.mark.parametrize("test_item", ALL_TESTS, ids=id_test)
+@pytest.mark.parametrize("test_item", ALL_TEST_OBJECTS, ids=id_test)
 def test_detector(test_item: Test, snapshot):
     test_dir_path = Path(
         TEST_DATA_DIR,
@@ -1681,38 +1671,6 @@ def test_detector(test_item: Test, snapshot):
     assert snapshot() == actual_output
 
 
-def _generate_test(test_item: Test, skip_existing=False):
-    test_dir_path = Path(
-        TEST_DATA_DIR,
-        test_item.detector.ARGUMENT,
-        test_item.solc_ver,
-    ).as_posix()
-    test_file_path = Path(test_dir_path, test_item.test_file).as_posix()
-    expected_result_path = Path(test_dir_path, test_item.expected_result).absolute().as_posix()
-
-    if skip_existing:
-        if os.path.isfile(expected_result_path):
-            return
-
-    set_solc(test_item)
-    sl = Slither(test_file_path)
-    sl.register_detector(test_item.detector)
-    results = sl.run_detectors()
-
-    results_as_string = json.dumps(results)
-    test_file_path = test_file_path.replace("\\", "\\\\")
-    results_as_string = results_as_string.replace(test_file_path, GENERIC_PATH)
-
-    for additional_file in test_item.additional_files:
-        additional_path = Path(test_dir_path, additional_file).absolute().as_posix()
-        additional_path = additional_path.replace("\\", "\\\\")
-        results_as_string = results_as_string.replace(additional_path, GENERIC_PATH)
-
-    results = json.loads(results_as_string)
-    with open(expected_result_path, "w", encoding="utf8") as f:
-        f.write(json.dumps(results, indent=4))
-
-
 def _generate_compile(test_item: Test, skip_existing=False):
     test_dir_path = Path(
         TEST_DATA_DIR,
@@ -1733,13 +1691,9 @@ def _generate_compile(test_item: Test, skip_existing=False):
 
 if __name__ == "__main__":
     if len(sys.argv) != 2:
-        print("To generate the json artifacts run\n\tpython tests/test_detectors.py --generate")
-    elif sys.argv[1] == "--generate":
-        for next_test in ALL_TESTS:
-            _generate_test(next_test, skip_existing=True)
-    elif sys.argv[1] == "--overwrite":
-        for next_test in ALL_TESTS:
-            _generate_test(next_test)
+        print(
+            "To generate the zip artifacts run\n\tpython tests/e2e/tests/test_detectors.py --compile"
+        )
     elif sys.argv[1] == "--compile":
-        for next_test in ALL_TESTS:
+        for next_test in ALL_TEST_OBJECTS:
             _generate_compile(next_test, skip_existing=True)