Merge pull request #39 from privacybydesign/case-sensitive

Make email validation case insensitive

Author: w-ensink

backend/internal/validators/email_validator.go

@@ -8,7 +8,8 @@ import (
 type EmailValidator struct{}
 
 // ParseAndValidateEmailAddress checks whether the provided input is valid.
-// It accepts RFC-5322 formatted emailaddresses (i.e. "John Doe <john.doe@example.com>"), but only in lowercase.
+// It accepts RFC-5322 formatted emailaddresses (i.e. "John Doe <john.doe@example.com>").
+// Any uppercase characters in the address are normalized to lowercase.
 // It returns a boolean indicating validity, a parsed emailaddress (if valid) or an error message key (if invalid).
 // If valid, the second return value contains the parsed address from the RFC-5322 format (e.g. "john.doe@example.com").
 // If invalid, an error message is returned in the third return value.
@@ -29,11 +30,7 @@ func (v *EmailValidator) ParseAndValidateEmailAddress(email string) (bool, *stri
 		err := "error_email_format"
 		return false, nil, &err
 	} else {
-		// We only accept lowercase emailaddresses
-		if strings.ToLower(addr.Address) != addr.Address {
-			err := "error_email_format_lowercase"
-			return false, nil, &err
-		}
-		return true, &addr.Address, nil
+		normalized := strings.ToLower(addr.Address)
+		return true, &normalized, nil
 	}
 }

backend/internal/validators/email_validator_test.go

@@ -62,23 +62,26 @@ func Test_ParseAndValidateEmailAddress_Given_EmailAddressesWithQuotesOrIpDomains
 	}
 }
 
-func Test_ParseAndValidateEmailAddress_Given_AddressWithUppercase_Should_ReturnError(t *testing.T) {
+func Test_ParseAndValidateEmailAddress_Given_AddressWithUppercase_Should_NormalizeToLowercase(t *testing.T) {
 	ev := EmailValidator{}
 
-	testCases := []string{
-		"John Doe <John.Doe@Example.com>", // full name with angle brackets
-		"   John.Doe@Example.com",         // leading whitespaces
-		"\t\tJohn.Doe@Example.com",        // leading tabs
-		"John.Doe@Example.com   ",         // trailing whitespaces
-		"John.Doe@Example.com\t",          // trailing tabs
-		"John.Doe+tag@Example.com",        // with plus tag
+	testCases := []struct {
+		input    string
+		expected string
+	}{
+		{"John Doe <John.Doe@Example.com>", "john.doe@example.com"},
+		{"   John.Doe@Example.com", "john.doe@example.com"},
+		{"\t\tJohn.Doe@Example.com", "john.doe@example.com"},
+		{"John.Doe@Example.com   ", "john.doe@example.com"},
+		{"John.Doe@Example.com\t", "john.doe@example.com"},
+		{"John.Doe+tag@Example.com", "john.doe+tag@example.com"},
 	}
 
 	for _, tc := range testCases {
-		valid, parsedAddress, err := ev.ParseAndValidateEmailAddress(tc)
+		valid, parsedAddress, err := ev.ParseAndValidateEmailAddress(tc.input)
 
-		require.False(t, valid)
-		require.Nil(t, parsedAddress)
-		require.Equal(t, "error_email_format_lowercase", *err)
+		require.True(t, valid)
+		require.Nil(t, err)
+		require.Equal(t, tc.expected, *parsedAddress)
 	}
 }