[Junie]: feat: implement getOrElseThrow in Either class

arrow-libs/core/arrow-core/src/commonMain/kotlin/arrow/core/Either.kt

@@ -1344,6 +1344,32 @@ public inline infix fun <A, B> Either<A, B>.getOrElse(default: (A) -> B): B {
   }
 }
 
+/**
+ * Returns the right value [B] of this [Either],
+ * or throws an exception produced by applying the [onLeft] function to the left value [A].
+ *
+ * ```kotlin
+ * import arrow.core.Either
+ * import arrow.core.getOrElseThrow
+ * import io.kotest.assertions.throwables.shouldThrow
+ * import io.kotest.matchers.shouldBe
+ *
+ * fun test() {
+ *   Either.Right(12).getOrElseThrow { RuntimeException("Error: $it") } shouldBe 12
+ *   shouldThrow<RuntimeException> {
+ *     Either.Left("error").getOrElseThrow { RuntimeException("Error: $it") }
+ *   }.message shouldBe "Error: error"
+ * }
+ * ```
+ */
+public inline fun <A, B> Either<A, B>.getOrElseThrow(onLeft: (A) -> Throwable): B {
+  contract { callsInPlace(onLeft, InvocationKind.AT_MOST_ONCE) }
+  return when (this) {
+    is Left -> throw onLeft(this.value)
+    is Right -> this.value
+  }
+}
+
 /**
  * Returns the value from this [Right] or [Left].
  *

arrow-libs/core/arrow-core/src/commonTest/kotlin/arrow/core/EitherTest.kt

@@ -129,6 +129,21 @@ class EitherTest {
       Left(a).getOrElse { b } shouldBe b
     }
   }
+
+  @Test
+  fun getOrElseThrowOk() = runTest {
+    checkAll(Arb.int()) { a: Int ->
+      Right(a).getOrElseThrow { RuntimeException("Error: $it") } shouldBe a
+
+      val left: Either<String, Int> = Left("error")
+      try {
+        left.getOrElseThrow { RuntimeException("Error: $it") }
+        fail("Should have thrown an exception")
+      } catch (e: RuntimeException) {
+        e.message shouldBe "Error: error"
+      }
+    }
+  }
 
   @Test
   fun getOrNullOk() = runTest {