Added test suite for LengthRule

Author: ditschedev

src/test/java/dev/ditsche/validator/rule/ruleset/LengthRuleTest.java

@@ -0,0 +1,48 @@
+package dev.ditsche.validator.rule.ruleset;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class LengthRuleTest {
+
+    private final LengthRule lengthRule = new LengthRule(6);
+
+    @Test
+    public void shouldFailIfNoStringIsProvided() {
+        Stream.of(null, 1, new LinkedList<>(), 2.00f).forEach(value -> {
+            assertThat(lengthRule.passes(value).isPassed()).isFalse();
+        });
+    }
+
+    @Test
+    public void shouldFailIfValueIsTooLong() {
+        Stream.of("212.35.234.256", "Testing things", 7, List.of(1,2,3,4,5,6,7)).forEach(value -> {
+            assertThat(lengthRule.passes(value).isPassed()).isFalse();
+        });
+    }
+
+    @Test
+    public void shouldFailIfValueIsTooShort() {
+        Stream.of("", "Test", 5, List.of(1,2,3,4)).forEach(value -> {
+            assertThat(lengthRule.passes(value).isPassed()).isFalse();
+        });
+    }
+
+    @Test
+    public void shouldPassWithValidLengths() {
+        Stream.of("Tobias", "123456", 6, List.of(1,2,3,4,5,6)).forEach(value -> {
+            assertThat(lengthRule.passes(value).isPassed()).isTrue();
+        });
+    }
+
+    @Test
+    public void shouldReturnValidErrorMessage() {
+        assertThat(lengthRule.message("test")).isEqualTo("The field \"test\" needs to have a length of 6");
+    }
+
+}