From 824828087154b9b5e83dc07626dfba708f6c7241 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andreas=20Z=C3=B6llner?= <andi@go-for-fun.de>
Date: Mon, 13 Feb 2023 09:31:52 +0100
Subject: [PATCH] add ThrowingPredicate functions to default to true or false
 on exception for filtering streams

---
 .../pivovarit/function/ThrowingPredicate.java | 22 +++++++++++++++++++
 .../function/ThrowingPredicateTest.java       | 22 +++++++++++++++++--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/pivovarit/function/ThrowingPredicate.java b/src/main/java/com/pivovarit/function/ThrowingPredicate.java
index bb1086a..44c3b47 100644
--- a/src/main/java/com/pivovarit/function/ThrowingPredicate.java
+++ b/src/main/java/com/pivovarit/function/ThrowingPredicate.java
@@ -44,6 +44,28 @@ static <T> Predicate<T> unchecked(ThrowingPredicate<? super T, ?> predicate) {
         };
     }
 
+    static <T> Predicate<T> uncheckedFalse(ThrowingPredicate<? super T, ?> predicate) {
+        requireNonNull(predicate);
+        return t -> {
+            try {
+                return predicate.test(t);
+            } catch (final Exception e) {
+                return false;
+            }
+        };
+    }
+
+    static <T> Predicate<T> uncheckedTrue(ThrowingPredicate<? super T, ?> predicate) {
+        requireNonNull(predicate);
+        return t -> {
+            try {
+                return predicate.test(t);
+            } catch (final Exception e) {
+                return true;
+            }
+        };
+    }
+
     /**
      * @return Predicate instance that rethrows the checked exception using the Sneaky Throws pattern
      */
diff --git a/src/test/java/com/pivovarit/function/ThrowingPredicateTest.java b/src/test/java/com/pivovarit/function/ThrowingPredicateTest.java
index 68afa3f..139a72b 100644
--- a/src/test/java/com/pivovarit/function/ThrowingPredicateTest.java
+++ b/src/test/java/com/pivovarit/function/ThrowingPredicateTest.java
@@ -4,8 +4,7 @@
 
 import java.util.stream.Stream;
 
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.assertj.core.api.Assertions.*;
 
 class ThrowingPredicateTest {
 
@@ -36,4 +35,23 @@ void shouldWrapInRuntimeExWhenUsingStandardUtilsFunctions() {
           .hasMessage(cause.getMessage())
           .hasCause(cause);
     }
+
+    @Test
+    void returnValueWhenExceptionOccurs() {
+        Exception cause = new Exception("some message");
+
+        // given
+        ThrowingPredicate<Integer, Exception> predicate = i -> {
+            throw cause;
+        };
+
+        // when
+        assertThatCode(() -> Stream.of(42).anyMatch(i -> ThrowingPredicate.uncheckedFalse(predicate).test(i)))
+                .doesNotThrowAnyException();
+        assertThatCode(() -> Stream.of(42).anyMatch(i -> ThrowingPredicate.uncheckedTrue(predicate).test(i)))
+                .doesNotThrowAnyException();
+
+        assertThat(Stream.of(42).anyMatch(i -> ThrowingPredicate.uncheckedFalse(predicate).test(i))).isFalse();
+        assertThat(Stream.of(42).anyMatch(i -> ThrowingPredicate.uncheckedTrue(predicate).test(i))).isTrue();
+    }
 }
\ No newline at end of file