Add unit tests for class feign.Util (#844)

core/src/test/java/feign/UtilTest.java

@@ -13,6 +13,9 @@
  */
 package feign;
 
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.rules.ExpectedException;
 import org.junit.Test;
 import java.io.Reader;
 import java.lang.reflect.Type;
@@ -31,6 +34,9 @@ import static org.junit.Assert.assertEquals;
 
 public class UtilTest {
 
+  @Rule
+  public ExpectedException thrown = ExpectedException.none();
+
   @Test
   public void removesEmptyStrings() {
     String[] values = new String[] {"", null};
@@ -122,6 +128,114 @@ public class UtilTest {
     assertEquals(Object.class, last);
   }
 
+  @Test
+  public void checkArgumentInputFalseNotNullNullOutputIllegalArgumentException() {
+    // Arrange
+    final boolean expression = false;
+    final String errorMessageTemplate = "";
+    final Object[] errorMessageArgs = null;
+    // Act
+    thrown.expect(IllegalArgumentException.class);
+    Util.checkArgument(expression, errorMessageTemplate, errorMessageArgs);
+    // Method is not expected to return due to exception thrown
+  }
+
+  @Test
+  public void checkNotNullInputNullNotNullNullOutputNullPointerException() {
+    // Arrange
+    final Object reference = null;
+    final String errorMessageTemplate = "";
+    final Object[] errorMessageArgs = null;
+    // Act
+    thrown.expect(NullPointerException.class);
+    Util.checkNotNull(reference, errorMessageTemplate, errorMessageArgs);
+    // Method is not expected to return due to exception thrown
+  }
+
+  @Test
+  public void checkNotNullInputZeroNotNull0OutputZero() {
+    // Arrange
+    final Object reference = 0;
+    final String errorMessageTemplate = "   ";
+    final Object[] errorMessageArgs = {};
+    // Act
+    final Object retval = Util.checkNotNull(reference, errorMessageTemplate, errorMessageArgs);
+    // Assert result
+    Assert.assertEquals(new Integer(0), retval);
+  }
+
+  @Test
+  public void checkStateInputFalseNotNullNullOutputIllegalStateException() {
+    // Arrange
+    final boolean expression = false;
+    final String errorMessageTemplate = "";
+    final Object[] errorMessageArgs = null;
+    // Act
+    thrown.expect(IllegalStateException.class);
+    Util.checkState(expression, errorMessageTemplate, errorMessageArgs);
+    // Method is not expected to return due to exception thrown
+  }
+
+  @Test
+  public void emptyToNullInputNotNullOutputNotNull() {
+    // Arrange
+    final String string = "AAAAAAAA";
+    // Act
+    final String retval = Util.emptyToNull(string);
+    // Assert result
+    Assert.assertEquals("AAAAAAAA", retval);
+  }
+
+  @Test
+  public void emptyToNullInputNullOutputNull() {
+    // Arrange
+    final String string = null;
+    // Act
+    final String retval = Util.emptyToNull(string);
+    // Assert result
+    Assert.assertNull(retval);
+  }
+
+  @Test
+  public void isBlankInputNotNullOutputFalse() {
+    // Arrange
+    final String value = "AAAAAAAA";
+    // Act
+    final boolean retval = Util.isBlank(value);
+    // Assert result
+    Assert.assertEquals(false, retval);
+  }
+
+  @Test
+  public void isBlankInputNullOutputTrue() {
+    // Arrange
+    final String value = null;
+    // Act
+    final boolean retval = Util.isBlank(value);
+    // Assert result
+    Assert.assertEquals(true, retval);
+  }
+
+  @Test
+  public void isNotBlankInputNotNullOutputFalse() {
+    // Arrange
+    final String value = "";
+    // Act
+    final boolean retval = Util.isNotBlank(value);
+    // Assert result
+    Assert.assertEquals(false, retval);
+  }
+
+  @Test
+  public void isNotBlankInputNotNullOutputTrue() {
+    // Arrange
+    final String value = "AAAAAAAA";
+    // Act
+    final boolean retval = Util.isNotBlank(value);
+    // Assert result
+    Assert.assertEquals(true, retval);
+  }
+
   interface LastTypeParameter {
     final List<String> LIST_STRING = null;
     final Parameterized<List<String>> PARAMETERIZED_LIST_STRING = null;