add min/max length validation, improve tests

uuid_test.go

@@ -2,31 +2,32 @@ package validate
 
 import "testing"
 
-func TestInvalidUUID(t *testing.T) {
-	invalid := []string{
-		"Not a UUID",
-		"00000000-00-0000-0000-00000000000000",
-		"00000000000000000000000000000000",
-		"01234567-89ab-cdef-ghij-klmnopqrstuv",
+func TestUUID(t *testing.T) {
+	type TestCase struct {
+		Input string
+		Err   bool
 	}
 
-	for _, uuid := range invalid {
-		if err := UUID(uuid); err == nil {
-			t.Errorf("%s is not a valid UUID", uuid)
-		}
-	}
-}
-
-func TestValidUUID(t *testing.T) {
-	valid := []string{
-		"00000000-0000-0000-0000-000000000000",
-		"01234567-89ab-cdef-0123-456789abcdef",
-		"abcdef01-2345-6789-abcd-ef0123456789",
-	}
-
-	for _, uuid := range valid {
-		if err := UUID(uuid); err != nil {
-			t.Errorf("%s is a valid UUID", uuid)
+	testCases := []TestCase{
+		{Input: "00000000-0000-0000-0000-000000000000"},
+		{Input: "01234567-89ab-cdef-0123-456789abcdef"},
+		{Input: "abcdef01-2345-6789-abcd-ef0123456789"},
+		{Input: "Not a UUID", Err: true},
+		{Input: "00000000-00-0000-0000-00000000000000", Err: true},
+		{Input: "00000000000000000000000000000000", Err: true},
+		{Input: "01234567-89ab-cdef-ghij-klmnopqrstuv", Err: true},
+	}
+
+	for _, testCase := range testCases {
+		err := UUID(testCase.Input)
+		if testCase.Err {
+			if err == nil {
+				t.Errorf("Expected %q to be an invalid UUID; got nil", testCase.Input)
+			}
+		} else {
+			if err != nil {
+				t.Errorf("Expected %q to be a valid UUID; got %s", testCase.Input, err)
+			}
 		}
 	}
 }