Allow using null as expected value

.github/workflows/build.yml

@@ -28,13 +28,13 @@ jobs:
         fetch-depth: 0
     - uses: actions/setup-java@v4
       with:
-        cache: gradle
         distribution: temurin
         java-version: |
           11
           17
           21
-    - uses: gradle/actions/wrapper-validation@v3
+    - name: Setup Gradle
+      uses: gradle/actions/setup-gradle@v4
     - name: Build with Java ${{ matrix.java }}
       run: ./gradlew build --info --warning-mode=summary -PjavaVersion=${{ matrix.java }}
     - name: Sonar analysis

.github/workflows/codeql-analysis.yml

@@ -27,13 +27,13 @@ jobs:
 
     - uses: actions/setup-java@v4
       with:
-        cache: gradle
         distribution: temurin
         java-version: |
           11
           17
 
-    - uses: gradle/actions/wrapper-validation@v3
+    - name: Setup Gradle
+      uses: gradle/actions/setup-gradle@v4
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v3

.github/workflows/release.yml

@@ -35,7 +35,9 @@ jobs:
         with:
           distribution: "temurin"
           java-version: 11
-          cache: "gradle"
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v4
 
       - name: Build
         run: ./gradlew build --warning-mode all

CHANGELOG.md

@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.9.0] - unreleased
 
+## [0.8.1] - 2024-09-12
+
+* [#17](https://github.com/itsallcode/hamcrest-auto-matcher/pull/17): Allow using `null` as expected value
+
 ## [0.8.0] - 2024-09-01
 
 ### Changes

README.md

@@ -34,7 +34,7 @@ repositories {
 }
 
 dependencies {
-    testImplementation 'org.itsallcode:hamcrest-auto-matcher:0.8.0'
+    testImplementation 'org.itsallcode:hamcrest-auto-matcher:0.8.1'
 }
 ```
 
@@ -43,7 +43,7 @@ dependencies {
 <dependency>
     <groupId>org.itsallcode</groupId>
     <artifactId>hamcrest-auto-matcher</artifactId>
-    <version>0.8.0</version>
+    <version>0.8.1</version>
     <scope>test</scope>
 </dependency>
 ```

build.gradle

@@ -9,7 +9,7 @@ plugins {
 }
 
 group 'org.itsallcode'
-version = '0.8.0'
+version = '0.8.1'
 
 dependencies {
     api 'org.hamcrest:hamcrest:3.0'

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.10-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

src/main/java/org/itsallcode/matcher/auto/AutoConfigBuilder.java

@@ -65,7 +65,11 @@ MatcherConfig<T> build() {
         return configBuilder.build();
     }
 
+    @SuppressWarnings("unchecked")
     static <T> Matcher<T> createEqualToMatcher(final T expected) {
+        if (expected == null) {
+            return (Matcher<T>) Matchers.nullValue();
+        }
         final Class<? extends Object> type = expected.getClass();
         if (type.isArray()) {
             return createArrayMatcher(expected);

src/test/java/org/itsallcode/matcher/auto/AutoMatcherArrayTest.java

@@ -97,6 +97,16 @@ void testStringArrayEmpty() {
         assertValuesDoNotMatch(new String[] { "a" }, new String[0]);
     }
 
+    @Test
+    void testObjectArrayEmpty() {
+        assertValuesDoNotMatch(new Object[] { "a" }, new Object[0]);
+    }
+
+    @Test
+    void testObjectArrayMixed() {
+        assertValuesDoNotMatch(new Object[] { "a", null, 1 }, new Object[0]);
+    }
+
     @Test
     void testComplexObjectArrayMatch() {
         assertValuesMatch(new ArrayElement[] { new ArrayElement(1, "a") },

src/test/java/org/itsallcode/matcher/auto/AutoMatcherListTest.java

@@ -6,8 +6,7 @@
 import static org.itsallcode.matcher.auto.TestUtil.assertValuesDoNotMatch;
 import static org.itsallcode.matcher.auto.TestUtil.assertValuesMatch;
 
-import java.util.ArrayList;
-import java.util.LinkedList;
+import java.util.*;
 
 import org.itsallcode.matcher.model.DemoAttribute;
 import org.junit.jupiter.api.Test;
@@ -24,6 +23,11 @@ void testIncompatibleMemberTypes() {
         assertValuesDoNotMatch(asList("string"), asList(1));
     }
 
+    @Test
+    void testActualNull() {
+        assertValuesDoNotMatch(asList((String) null), asList("not null"));
+    }
+
     @Test
     void testIncompatibleMemberTypesComplexTypes() {
         assertValuesDoNotMatch(asList(new DemoAttribute("attr")), asList(1));
@@ -67,4 +71,20 @@ void testAsListAndNewArrayListWith1Entry() {
         list.add("value1");
         assertValuesMatch(asList("value1"), list);
     }
+
+    @Test
+    void testListOfAndNewArrayListWith1Entry() {
+        final ArrayList<String> list = new ArrayList<>();
+        list.add("value1");
+        assertValuesMatch(List.of("value1"), list);
+    }
+
+    @Test
+    void testListWithMultipleEntries() {
+        final ArrayList<String> list = new ArrayList<>();
+        list.add("value1");
+        list.add(null);
+        list.add("value2");
+        assertValuesMatch(asList("value1", null, "value2"), list);
+    }
 }

src/test/java/org/itsallcode/matcher/auto/AutoMatcherMapTest.java

@@ -33,6 +33,10 @@ void testSingletonMap() {
         assertValuesDoNotMatch(singletonMap("key1", "value1"), singletonMap("key2", "value2"));
     }
 
+    @Test
+    void testSingletonMapAndEmptyMapOf() {
+        assertValuesDoNotMatch(singletonMap("key1", "value1"), Map.of());
+    }
     @Test
     void testSingletonMapAndEmptyMap() {
         assertValuesDoNotMatch(singletonMap("key1", "value1"), emptyMap());
@@ -43,6 +47,11 @@ void testSingletonMapAndNewHashMap() {
         assertValuesDoNotMatch(singletonMap("key1", "value1"), new HashMap<>());
     }
 
+    @Test
+    void testMapWithNullEntry() {
+        assertValuesDoNotMatch(singletonMap("key1", null), new HashMap<>());
+    }
+
     @Test
     void testIncompatibleTypesClassNotPublic() {
         final List<String> actual = singletonList("value1");
@@ -57,10 +66,17 @@ void testAutoMatcherWorksForSingletonMapAndNewHashMapWith1Entry() {
         assertValuesMatch(singletonMap("key1", "value1"), map);
     }
 
+    @Test
+    void testHashMapWithNullEntry() {
+        final HashMap<Object, Object> map = new HashMap<>();
+        map.put("key1", null);
+        assertValuesMatch(singletonMap("key1", null), map);
+    }
+
     @Test
     void testSingletonMapAndNewHashMapWith1Entry() {
         final HashMap<Object, Object> map = new HashMap<>();
         map.put("key1", "value1");
-        assertValuesMatch(singletonMap("key1", "value1"), map);
+        assertValuesMatch(Map.of("key1", "value1"), map);
     }
 }

src/test/java/org/itsallcode/matcher/auto/AutoMatcherTest.java

@@ -41,6 +41,16 @@ void setup() {
         value2Equal = model("m", 2);
     }
 
+    @Test
+    void testNull() {
+        assertThat(null, AutoMatcher.equalTo(null));
+    }
+
+    @Test
+    void testNotNull() {
+        assertThat("null", not(AutoMatcher.equalTo(null)));
+    }
+
     @Test
     @SuppressWarnings("unchecked")
     void testIncompatibleTypes() {
@@ -81,11 +91,6 @@ void testEqualToNotEqual() {
         assertThat(value1, not(AutoMatcher.equalTo(value2)));
     }
 
-    @Test
-    void testEqualToNullThrowsNullPointerException() {
-        assertThrows(NullPointerException.class, () -> AutoMatcher.equalTo(null));
-    }
-
     @Test
     void testContainsActualEmptyListSuccess() {
         assertThat(emptyList(), AutoMatcher.contains());

src/test/java/org/itsallcode/matcher/test/MatcherTestBase.java

@@ -21,11 +21,6 @@ public abstract class MatcherTestBase<T> {
 
     protected abstract Function<T, Matcher<T>> createNewSUT();
 
-    @Test
-    void testNullObject() {
-        assertThrows(NullPointerException.class, () -> createMatcher(null));
-    }
-
     @Test
     void subjectUnderTestMustBeNotNull() {
         assertNotNull(createNewSUT());