Make LangCollectors.collect(...) null-safe

Author: garydgregory

src/changes/changes.xml

@@ -68,6 +68,7 @@ The <action> type attribute can be add,update,fix,remove.
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Make Failable.run(FailableRunnable) null-safe.</action>
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Make Failable.accept(*) null-safe.</action>
     <action                   type="fix" dev="ggregory" due-to="maxxedev, Piotr P. Karwasz, Gary Gregory">Improve container detection by mimicking systemd #1323.</action>
+    <action                   type="fix" dev="ggregory" due-to="Gary Gregory">Make LangCollectors.collect(...) null-safe.</action>
     <!-- ADD -->
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add Strings and refactor StringUtils.</action>
     <action issue="LANG-1747" type="add" dev="ggregory" due-to="Oliver B. Fischer, Gary Gregory">Add StopWatch.run([Failable]Runnable) and get([Failable]Supplier).</action>

src/main/java/org/apache/commons/lang3/stream/LangCollectors.java

@@ -100,15 +100,16 @@ public Supplier<A> supplier() {
      * @param <R>       the type of the result.
      * @param <A>       the intermediate accumulation type of the {@code Collector}.
      * @param collector the {@code Collector} describing the reduction.
-     * @param array     The array, assumed to be unmodified during use.
+     * @param array     The array, assumed to be unmodified during use, a null array treated as an empty array.
      * @return the result of the reduction
      * @see Stream#collect(Collector)
      * @see Arrays#stream(Object[])
      * @see Collectors
      * @since 3.16.0
      */
+    @SafeVarargs
     public static <T, R, A> R collect(final Collector<? super T, A, R> collector, final T... array) {
-        return Arrays.stream(array).collect(collector);
+        return Streams.of(array).collect(collector);
     }
 
     /**

src/test/java/org/apache/commons/lang3/stream/LangCollectorsTest.java

@@ -74,7 +74,7 @@ private String join4(final Object... objects) {
         return LangCollectors.collect(JOINING_4, objects);
     }
 
-    private String join4Nul(final Object... objects) {
+    private String join4NullToString(final Object... objects) {
         return LangCollectors.collect(JOINING_4_NUL, objects);
     }
 
@@ -127,11 +127,19 @@ public void testJoinCollectNonStrings4Args() {
         assertEquals("<1-2>", join4(_1L, _2L));
         assertEquals("<1-2-3>", join4(_1L, _2L, _3L));
         assertEquals("<1-null-3>", join4(_1L, null, _3L));
-        assertEquals("<1-NUL-3>", join4Nul(_1L, null, _3L));
+        assertEquals("<1-NUL-3>", join4NullToString(_1L, null, _3L));
         assertEquals("<1-2>", join4(new AtomicLong(1), new AtomicLong(2)));
         assertEquals("<1-2>", join4(new Fixture(1), new Fixture(2)));
     }
 
+    @Test
+    public void testJoinCollectNullArgs() {
+        assertEquals("", join0((Object[]) null));
+        assertEquals("", join1((Object[]) null));
+        assertEquals("<>", join3((Object[]) null));
+        assertEquals("<>", join4NullToString((Object[]) null));
+    }
+
     @Test
     public void testJoinCollectStrings0Arg() {
         assertEquals("", join0());
@@ -157,7 +165,7 @@ public void testJoinCollectStrings4Args() {
         assertEquals("<1-2>", join4("1", "2"));
         assertEquals("<1-2-3>", join4("1", "2", "3"));
         assertEquals("<1-null-3>", join4("1", null, "3"));
-        assertEquals("<1-NUL-3>", join4Nul("1", null, "3"));
+        assertEquals("<1-NUL-3>", join4NullToString("1", null, "3"));
     }
 
     @Test