Merge "Add CollectionUtils.indexOf"

2 files changed, 23 insertions, 2 deletions

diff --git a/common/framework/com/android/net/module/util/CollectionUtils.java b/common/framework/com/android/net/module/util/CollectionUtils.java
index e5bb58d4..115f19d0 100644
--- a/common/framework/com/android/net/module/util/CollectionUtils.java
+++ b/common/framework/com/android/net/module/util/CollectionUtils.java
@@ -76,15 +76,26 @@ public final class CollectionUtils {
         return true;
 
     }
+
     /**
      * @return True if any element satisfies the predicate, false otherwise.
      *   Note that means this always returns false for empty collections.
      */
     public static <T> boolean any(@NonNull Collection<T> elem, @NonNull Predicate<T> predicate) {
+        return indexOf(elem, predicate) >= 0;
+    }
+
+    /**
+     * @return The index of the first element that matches the predicate, or -1 if none.
+     */
+    @Nullable
+    public static <T> int indexOf(@NonNull Collection<T> elem, @NonNull Predicate<T> predicate) {
+        int idx = 0;
         for (final T e : elem) {
-            if (predicate.test(e)) return true;
+            if (predicate.test(e)) return idx;
+            idx++;
         }
-        return false;
+        return -1;
     }
 
     /**
diff --git a/common/tests/unit/src/com/android/net/module/util/CollectionUtilsTest.kt b/common/tests/unit/src/com/android/net/module/util/CollectionUtilsTest.kt
index 00077420..08864265 100644
--- a/common/tests/unit/src/com/android/net/module/util/CollectionUtilsTest.kt
+++ b/common/tests/unit/src/com/android/net/module/util/CollectionUtilsTest.kt
@@ -20,6 +20,7 @@ import androidx.test.filters.SmallTest
 import androidx.test.runner.AndroidJUnit4
 import org.junit.Test
 import org.junit.runner.RunWith
+import kotlin.test.assertEquals
 import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
@@ -40,6 +41,15 @@ class CollectionUtilsTest {
     }
 
     @Test
+    fun testIndexOf() {
+        assertEquals(4, CollectionUtils.indexOf(listOf("A", "B", "C", "D", "E")) { it == "E" })
+        assertEquals(0, CollectionUtils.indexOf(listOf("A", "B", "C", "D", "E")) { it == "A" })
+        assertEquals(1, CollectionUtils.indexOf(listOf("AA", "BBB", "CCCC")) { it.length >= 3 })
+        assertEquals(1, CollectionUtils.indexOf(listOf("AA", null, "CCCC")) { it == null })
+        assertEquals(1, CollectionUtils.indexOf(listOf(null, "CCCC")) { it != null })
+    }
+
+    @Test
     fun testAll() {
         assertFalse(CollectionUtils.all(listOf("A", "B", "C", "D", "E")) { it != "E" })
         assertTrue(CollectionUtils.all(listOf("A", "B", "C", "D", "E")) { it != "F" })