Don't allow missing snapshots without --snapshot-update

snapshottest/module.py

@@ -24,6 +24,7 @@ def __init__(self, module, filepath):
         self.imports = defaultdict(set)
         self.visited_snapshots = set()
         self.new_snapshots = set()
+        self.missing_snapshots = set()
         self.failed_snapshots = set()
         self.imports["snapshottest"].add("Snapshot")
 
@@ -89,6 +90,10 @@ def stats_visited_snapshots(cls):
     def stats_new_snapshots(cls):
         return cls.stats_for_module(lambda module: len(module.new_snapshots))
 
+    @classmethod
+    def stats_missing_snapshots(cls):
+        return cls.stats_for_module(lambda module: len(module.missing_snapshots))
+
     @classmethod
     def stats_failed_snapshots(cls):
         return cls.stats_for_module(lambda module: len(module.failed_snapshots))
@@ -130,6 +135,9 @@ def __setitem__(self, key, value):
     def mark_failed(self, key):
         return self.failed_snapshots.add(key)
 
+    def mark_missing(self, key):
+        return self.missing_snapshots.add(key)
+
     @property
     def snapshot_dir(self):
         return os.path.dirname(self.filepath)
@@ -202,18 +210,15 @@ def get_module_for_testpath(cls, test_filepath):
 class SnapshotTest(object):
     _current_tester = None
 
-    def __init__(self):
+    def __init__(self, snapshot_should_update):
         self.curr_snapshot = ""
         self.snapshot_counter = 1
+        self.snapshot_should_update = snapshot_should_update
 
     @property
     def module(self):
         raise NotImplementedError("module property needs to be implemented")
 
-    @property
-    def update(self):
-        return False
-
     @property
     def test_name(self):
         raise NotImplementedError("test_name property needs to be implemented")
@@ -232,6 +237,9 @@ def visit(self):
     def fail(self):
         self.module.mark_failed(self.test_name)
 
+    def missing(self):
+        self.module.mark_missing(self.test_name)
+
     def store(self, data):
         formatter = Formatter.get_formatter(data)
         data = formatter.store(self, data)
@@ -249,13 +257,16 @@ def assert_equals(self, value, snapshot):
     def assert_match(self, value, name=""):
         self.curr_snapshot = name or self.snapshot_counter
         self.visit()
-        if self.update:
+        if self.snapshot_should_update:
             self.store(value)
         else:
             try:
                 prev_snapshot = self.module[self.test_name]
             except SnapshotNotFound:
-                self.store(value)  # first time this test has been seen
+                # There is no snapshot for this test, run with --snapshot-update
+                # to create it
+                self.missing()
+                raise
             else:
                 try:
                     self.assert_value_matches_snapshot(value, prev_snapshot)

snapshottest/pytest.py

@@ -27,16 +27,12 @@ def pytest_addoption(parser):
 class PyTestSnapshotTest(SnapshotTest):
     def __init__(self, request=None):
         self.request = request
-        super(PyTestSnapshotTest, self).__init__()
+        super(PyTestSnapshotTest, self).__init__(request.config.option.snapshot_update)
 
     @property
     def module(self):
         return SnapshotModule.get_module_for_testpath(self.request.node.fspath.strpath)
 
-    @property
-    def update(self):
-        return self.request.config.option.snapshot_update
-
     @property
     def test_name(self):
         cls_name = getattr(self.request.node.cls, "__name__", "")

snapshottest/reporting.py

@@ -7,11 +7,17 @@
 def reporting_lines(testing_cli):
     successful_snapshots = SnapshotModule.stats_successful_snapshots()
     bold = ["bold"]
+    new_snapshots = SnapshotModule.stats_new_snapshots()
     if successful_snapshots:
         yield (colored("{} snapshots passed", attrs=bold) + ".").format(
             successful_snapshots
         )
-    new_snapshots = SnapshotModule.stats_new_snapshots()
+    missing_snapshots = SnapshotModule.stats_missing_snapshots()
+    if missing_snapshots[0]:
+        yield (
+            colored("{} snapshots missing", "red", attrs=bold)
+            + " in {} test suites. Run with `--snapshot-update` to create them."
+        ).format(*missing_snapshots)
     if new_snapshots[0]:
         yield (
             colored("{} snapshots written", "green", attrs=bold) + " in {} test suites."
@@ -46,9 +52,7 @@ def diff_report(left, right):
         + colored("Received value", "red", attrs=["bold"])
         + colored(" does not match ", attrs=["bold"])
         + colored(
-            "stored snapshot `{}`".format(
-                left.snapshottest.test_name,
-            ),
+            "stored snapshot `{}`".format(left.snapshottest.test_name),
             "green",
             attrs=["bold"],
         )

snapshottest/unittest.py

@@ -13,17 +13,12 @@ def __init__(self, test_class, test_id, test_filepath, should_update, assertEqua
         self.test_id = test_id
         self.test_filepath = test_filepath
         self.assertEqual = assertEqual
-        self.should_update = should_update
-        super(UnitTestSnapshotTest, self).__init__()
+        super(UnitTestSnapshotTest, self).__init__(should_update)
 
     @property
     def module(self):
         return SnapshotModule.get_module_for_testpath(self.test_filepath)
 
-    @property
-    def update(self):
-        return self.should_update
-
     def assert_equals(self, value, snapshot):
         self.assertEqual(value, snapshot)
 

tests/test_formatter.py

@@ -75,16 +75,7 @@ def test_can_normalize_iterator_objects():
 
 
 @pytest.mark.parametrize(
-    "value",
-    [
-        0,
-        12.7,
-        True,
-        False,
-        None,
-        float("-inf"),
-        float("inf"),
-    ],
+    "value", [0, 12.7, True, False, None, float("-inf"), float("inf")]
 )
 def test_basic_formatting_parsing(value):
     formatter = Formatter()

tests/test_pytest.py

@@ -21,6 +21,7 @@ def pytest_snapshot_test(request, _apply_options):
 
 class TestPyTestSnapShotTest:
     def test_property_test_name(self, pytest_snapshot_test):
+        pytest_snapshot_test.snapshot_should_update = True
         pytest_snapshot_test.assert_match("counter")
         assert (
             pytest_snapshot_test.test_name
@@ -41,6 +42,7 @@ def test_property_test_name(self, pytest_snapshot_test):
 
 
 def test_pytest_snapshottest_property_test_name(pytest_snapshot_test):
+    pytest_snapshot_test.snapshot_should_update = True
     pytest_snapshot_test.assert_match("counter")
     assert (
         pytest_snapshot_test.test_name
@@ -64,6 +66,7 @@ def test_pytest_snapshottest_property_test_name(pytest_snapshot_test):
 def test_pytest_snapshottest_property_test_name_parametrize_singleline(
     pytest_snapshot_test, arg
 ):
+    pytest_snapshot_test.snapshot_should_update = True
     pytest_snapshot_test.assert_match("counter")
     assert (
         pytest_snapshot_test.test_name
@@ -84,6 +87,7 @@ def test_pytest_snapshottest_property_test_name_parametrize_singleline(
 def test_pytest_snapshottest_property_test_name_parametrize_multiline(
     pytest_snapshot_test, arg
 ):
+    pytest_snapshot_test.snapshot_should_update = True
     pytest_snapshot_test.assert_match("counter")
     assert (
         pytest_snapshot_test.test_name

tests/test_snapshot_test.py

@@ -4,6 +4,7 @@
 from collections import OrderedDict
 
 from snapshottest.module import SnapshotModule, SnapshotTest
+from snapshottest.error import SnapshotNotFound
 
 
 class GenericSnapshotTest(SnapshotTest):
@@ -15,7 +16,7 @@ def __init__(self, snapshot_module, update=False, current_test_id=None):
             "update": update,
             "current_test_id": current_test_id or "test_mocked",
         }
-        super(GenericSnapshotTest, self).__init__()
+        super(GenericSnapshotTest, self).__init__(update)
 
     @property
     def module(self):
@@ -33,7 +34,7 @@ def test_name(self):
 
     def reinitialize(self):
         """Reset internal state, as though starting a new test run"""
-        super(GenericSnapshotTest, self).__init__()
+        super(GenericSnapshotTest, self).__init__(False)
 
 
 def assert_snapshot_test_ran(snapshot_test, test_name=None):
@@ -91,6 +92,7 @@ def fixture_snapshot_test(tmpdir):
 @pytest.mark.parametrize("value", SNAPSHOTABLE_VALUES, ids=repr)
 def test_snapshot_matches_itself(snapshot_test, value):
     # first run stores the value as the snapshot
+    snapshot_test.snapshot_should_update = True
     snapshot_test.assert_match(value)
     assert_snapshot_test_succeeded(snapshot_test)
 
@@ -115,6 +117,7 @@ def test_snapshot_matches_itself(snapshot_test, value):
 )
 def test_snapshot_does_not_match_other_values(snapshot_test, value, other_value):
     # first run stores the value as the snapshot
+    snapshot_test.snapshot_should_update = True
     snapshot_test.assert_match(value)
     assert_snapshot_test_succeeded(snapshot_test)
 
@@ -123,3 +126,11 @@ def test_snapshot_does_not_match_other_values(snapshot_test, value, other_value)
     with pytest.raises(AssertionError):
         snapshot_test.assert_match(other_value)
     assert_snapshot_test_failed(snapshot_test)
+
+
+def test_first_run_without_snapshots_fails(snapshot_test):
+    with pytest.raises(SnapshotNotFound):
+        snapshot_test.assert_match("foo", name="no_snapshot_exists_test")
+    assert snapshot_test.module.missing_snapshots == set(
+        ["test_mocked no_snapshot_exists_test"]
+    )

tests/test_sorted_dict.py

@@ -42,10 +42,7 @@ class Fruit(enum.IntEnum):
         APPLE = 1
         ORANGE = 2
 
-    dic = {
-        Fruit.APPLE: 100,
-        Fruit.ORANGE: 400,
-    }
+    dic = {Fruit.APPLE: 100, Fruit.ORANGE: 400}
     assert SortedDict(dic)[Fruit.APPLE] == dic[Fruit.APPLE]
     assert SortedDict(dic)[Fruit.ORANGE] == dic[Fruit.ORANGE]
 
@@ -55,10 +52,7 @@ class Fruit(enum.Enum):
         APPLE = 1
         ORANGE = 2
 
-    dic = {
-        Fruit.APPLE: 100,
-        Fruit.ORANGE: 400,
-    }
+    dic = {Fruit.APPLE: 100, Fruit.ORANGE: 400}
     assert SortedDict(dic)[Fruit.APPLE] == dic[Fruit.APPLE]
     assert SortedDict(dic)[Fruit.ORANGE] == dic[Fruit.ORANGE]