Fix algebra

Author: aleksandar-apostolov

stream-android-core/src/main/java/io/getstream/android/core/api/utils/Algebra.kt

@@ -47,5 +47,14 @@ public operator fun Throwable.plus(other: Throwable): StreamAggregateException {
  *   [StreamAggregateException] if either [Result] is a failure.
  */
 @StreamInternalApi
-public operator fun <T, R> Result<T>.times(other: Result<R>): Result<Pair<T, R>> =
-    this.flatMap { first -> other.map { second -> first to second } }
+public operator fun <T, R> Result<T>.times(other: Result<R>): Result<Pair<T, R>> {
+    when {
+        this.isFailure && other.isFailure -> {
+            return Result.failure(this.exceptionOrNull()!! + other.exceptionOrNull()!!)
+        }
+
+        this.isFailure -> return Result.failure(this.exceptionOrNull()!!)
+        other.isFailure -> return Result.failure(other.exceptionOrNull()!!)
+    }
+    return Result.success(this.getOrThrow() to other.getOrThrow())
+}

stream-android-core/src/test/java/io/getstream/android/core/api/utils/AlgebraTest.kt

@@ -103,4 +103,18 @@ class AlgebraTest {
         assertTrue(combined.isFailure)
         assertSame(failure, combined.exceptionOrNull())
     }
+
+    @Test
+    fun `times propagates both results when both fail`() {
+        val failure = IllegalArgumentException("broken")
+        val failure2 = IllegalArgumentException("broken2")
+        val left = Result.failure<String>(failure)
+        val right = Result.failure<String>(failure2)
+
+        val combined = left * right
+
+        assertTrue(combined.isFailure)
+        val exception = combined.exceptionOrNull() as StreamAggregateException
+        assertEquals(listOf(failure, failure2), exception.causes)
+    }
 }