more tests; several assertions for the programmer

org.springframework.core/src/main/java/org/springframework/core/convert/TypeDescriptor.java

@@ -135,6 +135,9 @@ public class TypeDescriptor {
 	 * @return the collection type descriptor
 	 */
 	public static TypeDescriptor collection(Class<?> collectionType, TypeDescriptor elementType) {
+		if (!Collection.class.isAssignableFrom(collectionType)) {
+			throw new IllegalArgumentException("collectionType must be a java.util.Collection");
+		}
 		return new TypeDescriptor(collectionType, elementType);
 	}
 
@@ -148,6 +151,9 @@ public class TypeDescriptor {
 	 * @return the map type descriptor
 	 */
 	public static TypeDescriptor map(Class<?> mapType, TypeDescriptor keyType, TypeDescriptor valueType) {
+		if (!Map.class.isAssignableFrom(mapType)) {
+			throw new IllegalArgumentException("mapType must be a java.util.Map");
+		}
 		return new TypeDescriptor(mapType, keyType, valueType);
 	}
 	

org.springframework.core/src/test/java/org/springframework/core/convert/TypeDescriptorTests.java

@@ -719,7 +719,85 @@ public class TypeDescriptorTests {
 	}
 
 	@Test
-	public void testEquals() throws Exception {
+	public void collection() {
+		TypeDescriptor desc = TypeDescriptor.collection(List.class, TypeDescriptor.valueOf(Integer.class));
+		assertEquals(List.class, desc.getType());
+		assertEquals(List.class, desc.getObjectType());
+		assertEquals("java.util.List", desc.getName());
+		assertEquals("java.util.List<java.lang.Integer>", desc.toString());
+		assertTrue(!desc.isPrimitive());
+		assertEquals(0, desc.getAnnotations().length);
+		assertTrue(desc.isCollection());
+		assertFalse(desc.isArray());
+		assertEquals(Integer.class, desc.getElementType());
+		assertEquals(TypeDescriptor.valueOf(Integer.class), desc.getElementTypeDescriptor());
+		assertFalse(desc.isMap());
+		assertNull(desc.getMapKeyType());
+		assertEquals(TypeDescriptor.NULL, desc.getMapKeyTypeDescriptor());
+		assertNull(desc.getMapValueType());
+		assertEquals(TypeDescriptor.NULL, desc.getMapValueTypeDescriptor());		
+	}
+
+	@Test
+	public void collectionNested() {
+		TypeDescriptor desc = TypeDescriptor.collection(List.class, TypeDescriptor.collection(List.class, TypeDescriptor.valueOf(Integer.class)));
+		assertEquals(List.class, desc.getType());
+		assertEquals(List.class, desc.getObjectType());
+		assertEquals("java.util.List", desc.getName());
+		assertEquals("java.util.List<java.util.List<java.lang.Integer>>", desc.toString());
+		assertTrue(!desc.isPrimitive());
+		assertEquals(0, desc.getAnnotations().length);
+		assertTrue(desc.isCollection());
+		assertFalse(desc.isArray());
+		assertEquals(List.class, desc.getElementType());
+		assertEquals(TypeDescriptor.valueOf(Integer.class), desc.getElementTypeDescriptor().getElementTypeDescriptor());
+		assertFalse(desc.isMap());
+		assertNull(desc.getMapKeyType());
+		assertEquals(TypeDescriptor.NULL, desc.getMapKeyTypeDescriptor());
+		assertNull(desc.getMapValueType());
+		assertEquals(TypeDescriptor.NULL, desc.getMapValueTypeDescriptor());
+	}
+
+	@Test
+	public void map() {
+		TypeDescriptor desc = TypeDescriptor.map(Map.class, TypeDescriptor.valueOf(String.class), TypeDescriptor.valueOf(Integer.class));
+		assertEquals(Map.class, desc.getType());
+		assertEquals(Map.class, desc.getObjectType());
+		assertEquals("java.util.Map", desc.getName());
+		assertEquals("java.util.Map<java.lang.String, java.lang.Integer>", desc.toString());
+		assertTrue(!desc.isPrimitive());
+		assertEquals(0, desc.getAnnotations().length);
+		assertFalse(desc.isCollection());
+		assertFalse(desc.isArray());
+		assertNull(desc.getElementType());
+		assertEquals(TypeDescriptor.NULL, desc.getElementTypeDescriptor());
+		assertTrue(desc.isMap());
+		assertEquals(String.class, desc.getMapKeyTypeDescriptor().getType());
+		assertEquals(Integer.class, desc.getMapValueTypeDescriptor().getType());
+	}
+
+	@Test
+	public void mapNested() {
+		TypeDescriptor desc = TypeDescriptor.map(Map.class, TypeDescriptor.valueOf(String.class), 
+				TypeDescriptor.map(Map.class, TypeDescriptor.valueOf(String.class), TypeDescriptor.valueOf(Integer.class)));
+		assertEquals(Map.class, desc.getType());
+		assertEquals(Map.class, desc.getObjectType());
+		assertEquals("java.util.Map", desc.getName());
+		assertEquals("java.util.Map<java.lang.String, java.util.Map<java.lang.String, java.lang.Integer>>", desc.toString());
+		assertTrue(!desc.isPrimitive());
+		assertEquals(0, desc.getAnnotations().length);
+		assertFalse(desc.isCollection());
+		assertFalse(desc.isArray());
+		assertNull(desc.getElementType());
+		assertEquals(TypeDescriptor.NULL, desc.getElementTypeDescriptor());
+		assertTrue(desc.isMap());
+		assertEquals(String.class, desc.getMapKeyTypeDescriptor().getType());
+		assertEquals(String.class, desc.getMapValueTypeDescriptor().getMapKeyTypeDescriptor().getType());
+		assertEquals(Integer.class, desc.getMapValueTypeDescriptor().getMapValueTypeDescriptor().getType());
+	}
+
+	@Test
+	public void equals() throws Exception {
 		TypeDescriptor t1 = TypeDescriptor.valueOf(String.class);
 		TypeDescriptor t2 = TypeDescriptor.valueOf(String.class);
 		TypeDescriptor t3 = TypeDescriptor.valueOf(Date.class);