Merge pull request #1294 from yadavan88/zip-zipAll-zipWithIndex

zip, zipWithIndex and zipAll method usage in Scala

Author: dominiqueplante

scala-core-collections-modules/scala-core-collections-3/src/test/scala/com/baeldung/scala/zipvariants/ZipVariantUnitTest.scala

@@ -0,0 +1,48 @@
+package com.baeldung.scala.zipvariants
+
+import org.scalatest.wordspec.AnyWordSpec
+
+class ZipVariantUnitTest extends AnyWordSpec {
+
+  "zip method" should {
+    "combine two collections of equal size correctly" in {
+      val numbers = List(1, 2, 3)
+      val words = List("one", "two", "three")
+      val zipped = numbers.zip(words)
+      assert(zipped == List((1, "one"), (2, "two"), (3, "three")))
+    }
+
+    "drop elements from larger collection" in {
+      val numbers = List(1, 2, 3)
+      val words = List("one", "two", "three", "four")
+      val zipped = numbers.zip(words)
+      assert(zipped == List((1, "one"), (2, "two"), (3, "three")))
+    }
+  }
+
+  "zipAll" should {
+    "combine two collections of unequal size with default values" in {
+      val numbers = List(1, 2, 3)
+      val words = List("one", "two", "three", "four")
+      val zipped = numbers.zipAll(words, 0, "unknown")
+      assert(zipped == List((1, "one"), (2, "two"), (3, "three"), (0, "four")))
+      val zipped2 = numbers.zipAll(words.take(2), 0, "unknown")
+      assert(zipped2 == List((1, "one"), (2, "two"), (3, "unknown")))
+    }
+  }
+
+  "zipWithIndex" should {
+    "combine each element of a list with its corresponding index" in {
+      val words = List("one", "two", "three", "four")
+      assert(
+        words.zipWithIndex == List(
+          ("one", 0),
+          ("two", 1),
+          ("three", 2),
+          ("four", 3)
+        )
+      )
+    }
+  }
+
+}