Option<>.collect() not to call PartialFunction collector on arguments…

… where it is not defined (#2580)
vavr-io · Jul 14, 2021 · bd2127a · bd2127a
1 parent dba275f
commit bd2127a
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diff --git a/vavr/src/main/java/io/vavr/PartialFunction.java b/vavr/src/main/java/io/vavr/PartialFunction.java
@@ -123,7 +123,7 @@ public boolean isDefinedAt(V v) {
      *         if the function is defined for the given arguments, and {@code None} otherwise.
      */
     default Function1<T, Option<R>> lift() {
-        return t -> Option.when(isDefinedAt(t), apply(t));
+        return t -> Option.when(isDefinedAt(t), () -> apply(t));
     }
 
 }
diff --git a/vavr/src/test/java/io/vavr/control/OptionTest.java b/vavr/src/test/java/io/vavr/control/OptionTest.java
@@ -531,6 +531,12 @@ public void shouldThrowExceptionOnNullCollectPartialFunction() {
         Option.some(1).collect(pf);
     }
 
+    @Test
+    public void shouldNotCallPartialFunctionOnUndefinedArg() {
+        final PartialFunction<Integer, Integer> pf = Function1.<Integer, Integer> of(x -> 1/x).partial(i -> i != 0);
+        assertThat(Option.of(0).collect(pf)).isEqualTo(Option.none());
+    }
+
     // -- iterator
 
     @Test