Update mutable tests to JUnit Jupiter

Upgrade the tests in the mutable package to use JUnit Jupiter as
part of the effort to remove the dependency on the Vintage Engine.

While most of these changes are drop-in replacements with no functional
benefit, there are some non-obvious changes worth mentioning.

Unlike org.junit.Test, org.junit.jupiter.api.Test does not have an
"expected" argument. Instead, an explicit call to
org.junit.jupiter.api.Assertions.assertThrows is used.

Unlike org.junit.Assert.assertEquals(double, double, double),
org.junit.jupiter.api.Assertions.assertEquals(double, double, double)
does not support deltas of zero, only strictly positive deltas.
This issue will be addressed in JUnit Jupiter 5.4 (see
https://github.com/junit-team/junit5/pull/1613 for details). In the
meanwhile, assertTrue(expected==actual) was used, and TODO comments were
placed in the code to refactor it to assertEquals once JUnit 5.4 is
available.

It's also worth noting this is a minimal patch for migrating the
package's tests to Jupiter. There are several tests that can be made
more elegant with Jupiter's new features, but that work is left for
subsequent patches.

src/test/java/org/apache/commons/lang3/mutable/MutableBooleanTest.java

@@ -17,11 +17,12 @@
 
 package org.apache.commons.lang3.mutable;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * JUnit tests.
@@ -42,10 +43,10 @@ public void testCompareTo() {
         assertEquals(0, mutBool.compareTo(new MutableBoolean(true)));
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testCompareToNull() {
         final MutableBoolean mutBool = new MutableBoolean(false);
-        mutBool.compareTo(null);
+        assertThrows(NullPointerException.class, () -> mutBool.compareTo(null));
     }
 
     // ----------------------------------------------------------------
@@ -61,9 +62,9 @@ public void testConstructors() {
 
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testConstructorNull() {
-        new MutableBoolean(null);
+        assertThrows(NullPointerException.class, () -> new MutableBoolean(null));
     }
 
     @Test
@@ -115,10 +116,10 @@ public void testGetSet() {
 
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testSetNull() {
         final MutableBoolean mutBool = new MutableBoolean(false);
-        mutBool.setValue(null);
+        assertThrows(NullPointerException.class, () -> mutBool.setValue(null));
     }
 
     @Test

src/test/java/org/apache/commons/lang3/mutable/MutableByteTest.java

@@ -16,11 +16,12 @@
  */
 package org.apache.commons.lang3.mutable;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * JUnit tests.
@@ -43,9 +44,9 @@ public void testConstructors() {
 
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testConstructorNull() {
-        new MutableByte((Number)null);
+        assertThrows(NullPointerException.class, () -> new MutableByte((Number)null));
     }
 
     @Test
@@ -67,10 +68,10 @@ public void testGetSet() {
         assertEquals(Byte.valueOf((byte) 3), mutNum.getValue());
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testSetNull() {
         final MutableByte mutNum = new MutableByte((byte) 0);
-        mutNum.setValue(null);
+        assertThrows(NullPointerException.class, () -> mutNum.setValue(null));
     }
 
     @Test
@@ -112,18 +113,21 @@ public void testCompareTo() {
         assertEquals((byte) -1, mutNum.compareTo(new MutableByte((byte) 1)));
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testCompareToNull() {
         final MutableByte mutNum = new MutableByte((byte) 0);
-        mutNum.compareTo(null);
+        assertThrows(NullPointerException.class, () -> mutNum.compareTo(null));
     }
 
     @Test
     public void testPrimitiveValues() {
         final MutableByte mutNum = new MutableByte( (byte) 1 );
 
-        assertEquals( 1.0F, mutNum.floatValue(), 0 );
-        assertEquals( 1.0, mutNum.doubleValue(), 0 );
+        // TODO: JUnit Jupiter 5.3.1 doesn't support delta=0.
+        // This should be replaced when it is supported in JUnit Jupiter 5.4.
+        // See https://github.com/junit-team/junit5/pull/1613 for details.
+        assertTrue( 1.0F == mutNum.floatValue() );
+        assertTrue( 1.0 == mutNum.doubleValue() );
         assertEquals( (byte) 1, mutNum.byteValue() );
         assertEquals( (short) 1, mutNum.shortValue() );
         assertEquals( 1, mutNum.intValue() );

src/test/java/org/apache/commons/lang3/mutable/MutableDoubleTest.java

@@ -16,11 +16,12 @@
  */
 package org.apache.commons.lang3.mutable;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * JUnit tests.
@@ -43,9 +44,9 @@ public void testConstructors() {
 
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testConstructorNull() {
-        new MutableDouble((Number)null);
+        assertThrows(NullPointerException.class, () -> new MutableDouble((Number)null));
     }
 
     @Test
@@ -67,10 +68,10 @@ public void testGetSet() {
         assertEquals(Double.valueOf(3d), mutNum.getValue());
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testSetNull() {
         final MutableDouble mutNum = new MutableDouble(0d);
-        mutNum.setValue(null);
+        assertThrows(NullPointerException.class, () -> mutNum.setValue(null));
     }
 
     @Test
@@ -124,18 +125,21 @@ public void testCompareTo() {
         assertEquals(-1, mutNum.compareTo(new MutableDouble(1d)));
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testCompareToNull() {
         final MutableDouble mutNum = new MutableDouble(0d);
-        mutNum.compareTo(null);
+        assertThrows(NullPointerException.class, () -> mutNum.compareTo(null));
     }
 
     @Test
     public void testPrimitiveValues() {
         final MutableDouble mutNum = new MutableDouble(1.7);
 
-        assertEquals( 1.7F, mutNum.floatValue(), 0 );
-        assertEquals( 1.7, mutNum.doubleValue(), 0 );
+        // TODO: JUnit Jupiter 5.3.1 doesn't support delta=0.
+        // This should be replaced when it is supported in JUnit Jupiter 5.4.
+        // See https://github.com/junit-team/junit5/pull/1613 for details.
+        assertTrue ( 1.7F == mutNum.floatValue() );
+        assertTrue( 1.7 == mutNum.doubleValue() );
         assertEquals( (byte) 1, mutNum.byteValue() );
         assertEquals( (short) 1, mutNum.shortValue() );
         assertEquals( 1, mutNum.intValue() );

src/test/java/org/apache/commons/lang3/mutable/MutableFloatTest.java

@@ -16,11 +16,12 @@
  */
 package org.apache.commons.lang3.mutable;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * JUnit tests.
@@ -43,9 +44,9 @@ public void testConstructors() {
 
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testConstructorNull() {
-        new MutableFloat((Number)null);
+        assertThrows(NullPointerException.class, () -> new MutableFloat((Number)null));
     }
 
     @Test
@@ -67,10 +68,10 @@ public void testGetSet() {
         assertEquals(Float.valueOf(3f), mutNum.getValue());
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testSetNull() {
         final MutableFloat mutNum = new MutableFloat(0f);
-        mutNum.setValue(null);
+        assertThrows(NullPointerException.class, () -> mutNum.setValue(null));
     }
 
     @Test
@@ -124,10 +125,10 @@ public void testCompareTo() {
         assertEquals(-1, mutNum.compareTo(new MutableFloat(1f)));
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testCompareToNull() {
         final MutableFloat mutNum = new MutableFloat(0f);
-        mutNum.compareTo(null);
+        assertThrows(NullPointerException.class, () -> mutNum.compareTo(null));
     }
 
     @Test

src/test/java/org/apache/commons/lang3/mutable/MutableIntTest.java

@@ -16,11 +16,12 @@
  */
 package org.apache.commons.lang3.mutable;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * JUnit tests.
@@ -43,9 +44,9 @@ public void testConstructors() {
 
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testConstructorNull() {
-        new MutableInt((Number)null);
+        assertThrows(NullPointerException.class, () -> new MutableInt((Number)null));
     }
 
     @Test
@@ -67,10 +68,10 @@ public void testGetSet() {
         assertEquals(Integer.valueOf(3), mutNum.getValue());
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testSetNull() {
         final MutableInt mutNum = new MutableInt(0);
-        mutNum.setValue(null);
+        assertThrows(NullPointerException.class, () -> mutNum.setValue(null));
     }
 
     @Test
@@ -119,20 +120,23 @@ public void testCompareTo() {
         assertEquals(-1, mutNum.compareTo(new MutableInt(1)));
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testCompareToNull() {
         final MutableInt mutNum = new MutableInt(0);
-        mutNum.compareTo(null);
+        assertThrows(NullPointerException.class, () -> mutNum.compareTo(null));
     }
 
     @Test
     public void testPrimitiveValues() {
         final MutableInt mutNum = new MutableInt(1);
 
+        // TODO: JUnit Jupiter 5.3.1 doesn't support delta=0.
+        // This should be replaced when it is supported in JUnit Jupiter 5.4.
+        // See https://github.com/junit-team/junit5/pull/1613 for details.
         assertEquals( (byte) 1, mutNum.byteValue() );
         assertEquals( (short) 1, mutNum.shortValue() );
-        assertEquals( 1.0F, mutNum.floatValue(), 0 );
-        assertEquals( 1.0, mutNum.doubleValue(), 0 );
+        assertTrue( 1.0F == mutNum.floatValue() );
+        assertTrue( 1.0 == mutNum.doubleValue() );
         assertEquals( 1L, mutNum.longValue() );
     }
 

src/test/java/org/apache/commons/lang3/mutable/MutableLongTest.java

@@ -16,11 +16,12 @@
  */
 package org.apache.commons.lang3.mutable;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * JUnit tests.
@@ -43,9 +44,9 @@ public void testConstructors() {
 
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testConstructorNull() {
-        new MutableLong((Number)null);
+        assertThrows(NullPointerException.class, () -> new MutableLong((Number)null));
     }
 
     @Test
@@ -67,10 +68,10 @@ public void testGetSet() {
         assertEquals(Long.valueOf(3), mutNum.getValue());
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testSetNull() {
         final MutableLong mutNum = new MutableLong(0);
-        mutNum.setValue(null);
+        assertThrows(NullPointerException.class, () -> mutNum.setValue(null));
     }
 
     @Test
@@ -112,18 +113,21 @@ public void testCompareTo() {
         assertEquals(-1, mutNum.compareTo(new MutableLong(1)));
     }
 
-    @Test(expected=NullPointerException.class)
+    @Test
     public void testCompareToNull() {
         final MutableLong mutNum = new MutableLong(0);
-        mutNum.compareTo(null);
+        assertThrows(NullPointerException.class, () -> mutNum.compareTo(null));
     }
 
     @Test
     public void testPrimitiveValues() {
         final MutableLong mutNum = new MutableLong(1L);
 
-        assertEquals( 1.0F, mutNum.floatValue(), 0 );
-        assertEquals( 1.0, mutNum.doubleValue(), 0 );
+        // TODO: JUnit Jupiter 5.3.1 doesn't support delta=0.
+        // This should be replaced when it is supported in JUnit Jupiter 5.4.
+        // See https://github.com/junit-team/junit5/pull/1613 for details.
+        assertTrue( 1.0F == mutNum.floatValue() );
+        assertTrue ( 1.0 == mutNum.doubleValue() );
         assertEquals( (byte) 1, mutNum.byteValue() );
         assertEquals( (short) 1, mutNum.shortValue() );
         assertEquals( 1, mutNum.intValue() );

src/test/java/org/apache/commons/lang3/mutable/MutableObjectTest.java

@@ -16,13 +16,13 @@
  */
 package org.apache.commons.lang3.mutable;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 
 /**

src/test/java/org/apache/commons/lang3/mutable/MutableShortTest.java

@@ -16,12 +16,12 @@
  */
 package org.apache.commons.lang3.mutable;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
 
 /**
  * JUnit tests.
@@ -118,8 +118,11 @@ public void testCompareTo() {
     public void testPrimitiveValues() {
         final MutableShort mutNum = new MutableShort( (short) 1 );
 
-        assertEquals( 1.0F, mutNum.floatValue(), 0 );
-        assertEquals( 1.0, mutNum.doubleValue(), 0 );
+        // TODO: JUnit Jupiter 5.3.1 doesn't support delta=0.
+        // This should be replaced when it is supported in JUnit Jupiter 5.4.
+        // See https://github.com/junit-team/junit5/pull/1613 for details.
+        assertTrue ( 1.0F == mutNum.floatValue() );
+        assertTrue ( 1.0 == mutNum.doubleValue() );
         assertEquals( (byte) 1, mutNum.byteValue() );
         assertEquals( (short) 1, mutNum.shortValue() );
         assertEquals( 1, mutNum.intValue() );