#12 - Added methods that accepts/rejects predicate to WhereObject class

avegera · Jul 11, 2024 · 72dfd0f · 72dfd0f
1 parent 42a9068
commit 72dfd0f
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Showing 3 changed files with 120 additions and 1 deletion.
diff --git a/src/main/java/io/github/avegera/predicate4j/api/WhereObject.java b/src/main/java/io/github/avegera/predicate4j/api/WhereObject.java
@@ -1,5 +1,7 @@
 package io.github.avegera.predicate4j.api;
 
+import java.util.function.Predicate;
+
 public interface WhereObject<T, R> {
 
     RichPredicate<T> isEqualTo(R value);
@@ -13,4 +15,8 @@ public interface WhereObject<T, R> {
     RichPredicate<T> notInstanceOf(Class<?> clazz);
 
     RichPredicate<T> notNull();
+
+    RichPredicate<T> accepts(Predicate<R> predicate);
+
+    RichPredicate<T> rejects(Predicate<R> predicate);
 }
diff --git a/src/main/java/io/github/avegera/predicate4j/impl/WhereObjectImpl.java b/src/main/java/io/github/avegera/predicate4j/impl/WhereObjectImpl.java
@@ -7,6 +7,8 @@
 import java.util.function.Function;
 import java.util.function.Predicate;
 
+import static io.github.avegera.predicate4j.Predicates.alwaysTrue;
+
 public class WhereObjectImpl<T, R> implements WhereObject<T, R> {
 
     private final Function<T, R> mapper;
@@ -53,6 +55,16 @@ public RichPredicate<T> notNull() {
         return getPredicate(Predicates.notNull());
     }
 
+    @Override
+    public RichPredicate<T> accepts(Predicate<R> predicate) {
+        return getPredicate(predicate);
+    }
+
+    @Override
+    public RichPredicate<T> rejects(Predicate<R> predicate) {
+        return getPredicate(predicate == null ? alwaysTrue() : predicate.negate());
+    }
+
     protected RichPredicate<T> getPredicate(Predicate<R> predicate) {
         Predicate<T> currentPredicate = getPredicateWithMapper(mapper, predicate);
         if (previousPredicate == null) {
@@ -62,6 +74,6 @@ protected RichPredicate<T> getPredicate(Predicate<R> predicate) {
     }
 
     private Predicate<T> getPredicateWithMapper(Function<T, R> mapper, Predicate<R> predicate) {
-        return object -> object != null && predicate.test(mapper.apply(object));
+        return object -> object != null && predicate != null && predicate.test(mapper.apply(object));
     }
 }
diff --git a/src/test/java/io/github/avegera/predicate4j/WhereTest.java b/src/test/java/io/github/avegera/predicate4j/WhereTest.java
@@ -8,6 +8,7 @@
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Objects;
 import java.util.function.Predicate;
 
 import static io.github.avegera.predicate4j.Where.where;
@@ -281,6 +282,106 @@ void mappedValueIsInstanceOfProvidedClass() {
                 }
             }
         }
+
+        @Nested
+        @DisplayName(".accepts(predicate)")
+        class Accepts {
+
+            @Nested
+            @DisplayName("returns true when")
+            class ReturnsTrueWhen {
+
+                @Test
+                @DisplayName("predicate accepts the mapped value")
+                void predicateAcceptsMappedValue() {
+                    Predicate<User> predicate = where(User::id).accepts(id -> id == TEST_ID_1);
+                    assertThat(predicate).accepts(new User(TEST_ID_1));
+                }
+
+                @Test
+                @DisplayName("predicate accepts null value")
+                void predicateAcceptsNullValue() {
+                    Predicate<User> predicate = where(User::id).accepts(Objects::isNull);
+                    assertThat(predicate).accepts(new User(null));
+                }
+            }
+
+            @Nested
+            @DisplayName("returns false when")
+            class ReturnsFalseWhen {
+
+                @Test
+                @DisplayName("predicate does not accept the mapped value")
+                void predicateDoesNotAcceptMappedValue() {
+                    Predicate<User> predicate = where(User::id).accepts(id -> id == TEST_ID_1);
+                    assertThat(predicate).rejects(new User(TEST_ID_2));
+                }
+
+                @Test
+                @DisplayName("predicate does not accept non-null value")
+                void predicateDoesNotAcceptNonNullValue() {
+                    Predicate<User> predicate = where(User::id).accepts(Objects::isNull);
+                    assertThat(predicate).rejects(new User(TEST_ID_1));
+                }
+
+                @Test
+                @DisplayName("predicate is null")
+                void predicateIsNull() {
+                    Predicate<User> predicate = where(User::id).accepts(null);
+                    assertThat(predicate).rejects(new User(TEST_ID_1));
+                }
+            }
+        }
+
+        @Nested
+        @DisplayName(".rejects(predicate)")
+        class Rejects {
+
+            @Nested
+            @DisplayName("returns true when")
+            class ReturnsTrueWhen {
+
+                @Test
+                @DisplayName("predicate rejects the mapped value")
+                void predicateRejectsMappedValue() {
+                    Predicate<User> predicate = where(User::id).rejects(id -> id != TEST_ID_1);
+                    assertThat(predicate).accepts(new User(TEST_ID_1));
+                }
+
+                @Test
+                @DisplayName("predicate rejects null value")
+                void predicateRejectsNullValue() {
+                    Predicate<User> predicate = where(User::id).rejects(Objects::nonNull);
+                    assertThat(predicate).accepts(new User(null));
+                }
+
+                @Test
+                @DisplayName("predicate is null")
+                void predicateIsNull() {
+                    Predicate<User> predicate = where(User::id).rejects(null);
+                    assertThat(predicate).accepts(new User(TEST_ID_1));
+                }
+            }
+
+            @Nested
+            @DisplayName("returns false when")
+            class ReturnsFalseWhen {
+
+                @Test
+                @DisplayName("predicate does not reject the mapped value")
+                void predicateDoesNotRejectMappedValue() {
+                    Predicate<User> predicate = where(User::id).rejects(id -> id != TEST_ID_1);
+                    assertThat(predicate).rejects(new User(TEST_ID_2));
+                }
+
+                @Test
+                @DisplayName("predicate does not reject non-null value")
+                void predicateDoesNotRejectNonNullValue() {
+                    Predicate<User> predicate = where(User::id).rejects(Objects::nonNull);
+                    assertThat(predicate).rejects(new User(TEST_ID_1));
+                }
+            }
+        }
     }
 
     @Nested