Add Quality of a Map with a specific size, closes #186

confidence-core/src/main/java/org/saynotobugs/confidence/quality/map/HasSize.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2024 dmfs GmbH
+ *
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.saynotobugs.confidence.quality.map;
+
+import org.dmfs.srcless.annotations.staticfactory.StaticFactories;
+import org.saynotobugs.confidence.Quality;
+import org.saynotobugs.confidence.quality.composite.Has;
+import org.saynotobugs.confidence.quality.composite.QualityComposition;
+import org.saynotobugs.confidence.quality.object.EqualTo;
+
+import java.util.Map;
+
+
+@StaticFactories(
+    value = "Map",
+    packageName = "org.saynotobugs.confidence.core.quality")
+public final class HasSize extends QualityComposition<Map<?, ?>>
+{
+    /**
+     * Creates a {@link Quality} that matches if size of the {@link Map} under test is equal to the given value.
+     * <pre>
+     *     assertThat(Map.of("key1", "value1"), hasSize(1));
+     * </pre>
+     */
+    public HasSize(int elementCount)
+    {
+        this(new EqualTo<>(elementCount));
+    }
+
+
+    /**
+     * Creates a {@link Quality} that matches if the size {@link Map} under test matches the given {@link Quality}.
+     * <pre>
+     *     assertThat(Map.of("key1", "value1"), hasSize(lessThan(4)));
+     * </pre>
+     */
+    public HasSize(Quality<? super Integer> delegate)
+    {
+        super(new Has<>("size", Map::size, delegate));
+    }
+}

confidence-core/src/test/java/org/saynotobugs/confidence/quality/map/HasSizeTest.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2024 dmfs GmbH
+ *
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.saynotobugs.confidence.quality.map;
+
+import org.junit.jupiter.api.Test;
+import org.saynotobugs.confidence.quality.composite.AllOf;
+import org.saynotobugs.confidence.test.quality.Fails;
+import org.saynotobugs.confidence.test.quality.HasDescription;
+import org.saynotobugs.confidence.test.quality.Passes;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.saynotobugs.confidence.Assertion.assertThat;
+
+class HasSizeTest
+{
+    @Test
+    void testEmpty()
+    {
+        assertThat(new HasSize(0),
+            new AllOf<>(
+                new Passes<>(new HashMap<>(), Collections.EMPTY_MAP),
+                new Fails<>(Collections.singletonMap("a", 1), "had size <1>"),
+                new HasDescription("has size <0>")
+            ));
+    }
+
+    @Test
+    void testSingleton()
+    {
+        assertThat(new HasSize(1),
+            new AllOf<>(
+                new Passes<>(new HashMap<String, Integer>()
+                {{
+                    put("key1", 1);
+                }}),
+                new Fails<Map<String, Integer>>(Collections.emptyMap(), "had size <0>"),
+                new Fails<>(new HashMap<String, Integer>()
+                {{
+                    put("key1", 1);
+                    put("key2", 2);
+                }}, "had size <2>"),
+                new HasDescription("has size <1>")
+            ));
+    }
+
+
+    @Test
+    void testMultiple()
+    {
+        assertThat(new HasSize(3),
+            new AllOf<>(
+                new Passes<>(new HashMap<String, Integer>()
+                {{
+                    put("key1", 1);
+                    put("key2", 2);
+                    put("key3", 3);
+                }}),
+                new Fails<Map<String, Integer>>(Collections.emptyMap(), "had size <0>"),
+                new Fails<>(new HashMap<String, Integer>()
+                {{
+                    put("key1", 1);
+                    put("key2", 2);
+                }}, "had size <2>"),
+                new HasDescription("has size <3>")
+            ));
+    }
+}