Added any(Class<T>), null(Class<T>) and notNull(Class<T>) matchers, which returns

joe.walnes · joe.walnes · commit da09c483e82e · 2007-06-30T12:51:07.000Z
Matcher&lt;T&gt;. Helpful when the compiler struggles with type inference.
diff --git a/CHANGES.txt b/CHANGES.txt
@@ -20,6 +20,9 @@
 * Relaxed isInstanceOf() matcher generic type so it can be used on any kind of
   object. e.g. assertThat(someUnknownObject, isInstanceOf(String.class));
 
+* Added any(Class<T>), null(Class<T>) and notNull(Class<T>) matchers, which returns
+  Matcher<T>. Helpful when the compiler struggles with type inference.
+
 * Modified anyOf() and allOf() to accept mixed-types.
 
 * TypeSafeMatcher.matchesSafely() is now public.
diff --git a/hamcrest-core/src/main/java/org/hamcrest/core/IsAnything.java b/hamcrest-core/src/main/java/org/hamcrest/core/IsAnything.java
@@ -48,4 +48,12 @@ public static <T> Matcher<T> anything() {
     public static <T> Matcher<T> anything(String description) {
         return new IsAnything<T>(description);
     }
+
+    /**
+     * This matcher always evaluates to true. With type inference.
+     */
+    @Factory
+    public static <T> Matcher<T> any(@SuppressWarnings("unused")Class<T> type) {
+        return new IsAnything<T>();
+    }
 }
diff --git a/hamcrest-core/src/main/java/org/hamcrest/core/IsNull.java b/hamcrest-core/src/main/java/org/hamcrest/core/IsNull.java
@@ -35,5 +35,21 @@ public static <T> Matcher<T> nullValue() {
     public static <T> Matcher<T> notNullValue() {
         return not(IsNull.<T>nullValue());
     }
+
+    /**
+     * Matches if value is null. With type inference.
+     */
+    @Factory
+    public static <T> Matcher<T> nullValue(@SuppressWarnings("unused") Class<T> type) {
+        return nullValue();
+    }
+
+    /**
+     * Matches if value is not null. With type inference.
+     */
+    @Factory
+    public static <T> Matcher<T> notNullValue(@SuppressWarnings("unused") Class<T> type) {
+        return notNullValue();
+    }
 }
 
diff --git a/hamcrest-unit-test/src/main/java/org/hamcrest/core/IsAnythingTest.java b/hamcrest-unit-test/src/main/java/org/hamcrest/core/IsAnythingTest.java
@@ -2,6 +2,7 @@
  */
 package org.hamcrest.core;
 
+import static org.hamcrest.core.IsAnything.any;
 import org.hamcrest.AbstractMatcherTest;
 import org.hamcrest.Matcher;
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -27,4 +28,12 @@ public void testCanOverrideDescription() {
         String description = "description";
         assertDescription(description, anything(description));
     }
+
+    public void testSupportsStaticTyping() {
+        requiresStringMatcher(any(String.class));
+    }
+
+    private void requiresStringMatcher(Matcher<String> arg) {
+        // no-op
+    }
 }
diff --git a/hamcrest-unit-test/src/main/java/org/hamcrest/core/IsNullTest.java b/hamcrest-unit-test/src/main/java/org/hamcrest/core/IsNullTest.java
@@ -8,6 +8,8 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsNull.nullValue;
 import static org.hamcrest.core.IsNull.notNullValue;
+import static org.hamcrest.core.IsNull.*;
+import static org.hamcrest.core.IsAnything.any;
 
 public class IsNullTest extends AbstractMatcherTest {
 
@@ -22,4 +24,13 @@ public void testEvaluatesToTrueIfArgumentIsNull() {
         assertThat(ANY_NON_NULL_ARGUMENT, notNullValue());
         assertThat(null, not(notNullValue()));
     }
+
+    public void testSupportsStaticTyping() {
+        requiresStringMatcher(nullValue(String.class));
+        requiresStringMatcher(notNullValue(String.class));
+    }
+
+    private void requiresStringMatcher(Matcher<String> arg) {
+        // no-op
+    }    
 }

Original file line number	Diff line number	Diff line change
`@@ -48,4 +48,12 @@ public static <T> Matcher<T> anything() {`
`48`	`48`	`public static <T> Matcher<T> anything(String description) {`
`49`	`49`	`return new IsAnything<T>(description);`
`50`	`50`	`}`
	`51`	`+`
	`52`	`+ /**`
	`53`	`+ * This matcher always evaluates to true. With type inference.`
	`54`	`+ */`
	`55`	`+ @Factory`
	`56`	`+ public static <T> Matcher<T> any(@SuppressWarnings("unused")Class<T> type) {`
	`57`	`+ return new IsAnything<T>();`
	`58`	`+ }`
`51`	`59`	`}`