From 4afdad4f1a1909bddffa8b776f8c5e12b20445b5 Mon Sep 17 00:00:00 2001
From: Gary Gregory <garydgregory@gmail.com>
Date: Fri, 13 Oct 2023 10:59:10 -0400
Subject: [PATCH] Add Streams.failableStream(T...)

---
 src/changes/changes.xml                       |  1 +
 .../apache/commons/lang3/stream/Streams.java  | 13 ++++
 .../lang3/stream/FailableStreamTest.java      | 66 +++++++++++++++++++
 3 files changed, 80 insertions(+)
 create mode 100644 src/test/java/org/apache/commons/lang3/stream/FailableStreamTest.java

diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 0e7820796..4e6e6c479 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -70,6 +70,7 @@ The <action> type attribute can be add,update,fix,remove.
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add LocaleUtils.isLanguageUndetermined(Locale).</action>
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add ObjectUtils.toString(Supplier&lt;Object&gt;, Supplier&lt;String&gt;).</action>
     <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add LazyInitializer.isInitialized().</action>
+    <action                   type="add" dev="ggregory" due-to="Gary Gregory">Add Streams.failableStream(T...).</action>
     <!-- UPDATE -->
     <action                   type="update" dev="ggregory" due-to="Gary Gregory">Bump commons-parent from 58 to 64.</action>
     <action                   type="update" dev="ggregory" due-to="Gary Gregory">Bump org.easymock:easymock from 5.1.0 to 5.2.0 #1104.</action>
diff --git a/src/main/java/org/apache/commons/lang3/stream/Streams.java b/src/main/java/org/apache/commons/lang3/stream/Streams.java
index fa639ec2a..aa783eb8f 100644
--- a/src/main/java/org/apache/commons/lang3/stream/Streams.java
+++ b/src/main/java/org/apache/commons/lang3/stream/Streams.java
@@ -579,6 +579,19 @@ public class Streams {
         return new FailableStream<>(stream);
     }
 
+    /**
+     * Shorthand for {@code Streams.failableStream(Streams.of(arrayValues))}.
+     *
+     * @param <T> the type of stream elements.
+     * @param values the elements of the new stream, may be {@code null}.
+     * @return the new FailableStream on {@code values} or an empty stream.
+     * @since 3.14.0
+     */
+    @SafeVarargs // Creating a stream from an array is safe
+    public static <T> FailableStream<T> failableStream(final T... values) {
+        return failableStream(of(values));
+    }
+
     /**
      * Streams only instances of the give Class in a collection.
      * <p>
diff --git a/src/test/java/org/apache/commons/lang3/stream/FailableStreamTest.java b/src/test/java/org/apache/commons/lang3/stream/FailableStreamTest.java
new file mode 100644
index 000000000..6944bda73
--- /dev/null
+++ b/src/test/java/org/apache/commons/lang3/stream/FailableStreamTest.java
@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.commons.lang3.stream;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Locale;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.stream.Streams.FailableStream;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests {@link FailableStream}.
+ */
+public class FailableStreamTest {
+
+    private String failable(final String value) throws IOException {
+        if (value == new Object()) {
+            throw new IOException();
+        }
+        return value.toLowerCase(Locale.ROOT);
+    }
+
+    @Test
+    public void testFailableStreamOfArray() {
+        assertArrayEquals(new String[] {}, toArray());
+        assertArrayEquals(new String[] { "a" }, toArray("A"));
+        assertArrayEquals(new String[] { "a", "b" }, toArray("A", "B"));
+        assertArrayEquals(new String[] { "a", "b", "c" }, toArray("A", "B", "C"));
+    }
+
+    @Test
+    public void testFailableStreamOfCollection() {
+        assertArrayEquals(new String[] {}, toArray());
+        assertArrayEquals(new String[] { "a" }, toArray(Arrays.asList("A")));
+        assertArrayEquals(new String[] { "a", "b" }, toArray(Arrays.asList("A", "B")));
+        assertArrayEquals(new String[] { "a", "b", "c" }, toArray(Arrays.asList("A", "B", "C")));
+    }
+
+    private String[] toArray(final Collection<String> strings) {
+        return Streams.failableStream(strings).map(this::failable).collect(Collectors.toList()).toArray(new String[0]);
+    }
+
+    private String[] toArray(final String... strings) {
+        return Streams.failableStream(strings).map(this::failable).collect(Collectors.toList()).toArray(new String[0]);
+    }
+}