Add tests for new plugin: Email Address

tests/plugins/email_address_test.py

@@ -0,0 +1,60 @@
+import pytest
+from detect_secrets.plugins.email_address import EmailAddressDetector
+
+
+class TestEmailAddressDetector:
+    """
+    Testing strategy
+
+    Cover the cartesian product of these partitions:
+
+      1. Partition on email address format:
+        a. Valid email addresses
+        b. Invalid email addresses
+
+      2. Partition on line content:
+        a. email address is the only content
+        b. email address is part of a larger string
+
+    And cover these cases:
+
+      1. Partition on whitelist email addresses:
+        a. email address is in the whitelist
+        b. email address is not in the whitelist
+    """
+
+    @pytest.mark.parametrize(
+        'payload, should_flag',
+        [
+            # Valid email addresses, only content
+            ('[email protected]', True),
+            ('[email protected]', True),
+            ('[email protected]', True),
+            ('[email protected]', True),
+            ('[email protected]', True),
+            ('user@ex_ample.com', True),
+            ('[email protected]', True),
+            ('[email protected]', True),
+            ('[email protected]', True),
+            # Valid email addresses, part of larger string
+            ('This is an email address: [email protected]', True),
+            ('[email protected] is a valid email address', True),
+            # Invalid email addresses
+            ('user@com', False),
+            ('@example.com', False),
+            ('[email protected]', False),
+            ('[email protected]', False),
+            # Whitelist email addresses
+            ('[email protected]', False),
+            ('[email protected]', False),
+            # Non-whitelist email addresses
+            ('[email protected]', True),
+            ('[email protected]', True),
+            ('[email protected]', True),
+        ],
+    )
+    def test_analyze_line(self, payload, should_flag):
+        logic = EmailAddressDetector()
+
+        output = logic.analyze_line(filename='mock_filename', line=payload)
+        assert len(output) == int(should_flag)