From 3810567b6c4ca8639c5c4374ceae68bc424a5fa7 Mon Sep 17 00:00:00 2001
From: Joseph Cooper <cooper.joseph@gmail.com>
Date: Tue, 26 Oct 2021 15:28:33 +0100
Subject: [PATCH] Added contracts to throwIf and throwUnless

---
 .../result/coroutines/RunSuspendCatching.kt           |  4 ++++
 .../result/coroutines/RunSuspendCatchingTest.kt       | 11 +++++++++++
 .../com/github/michaelbull/result/ThrowIfUnless.kt    |  9 +++++++--
 3 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 kotlin-result-coroutines/src/commonMain/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatching.kt
 create mode 100644 kotlin-result-coroutines/src/jvmTest/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatchingTest.kt

diff --git a/kotlin-result-coroutines/src/commonMain/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatching.kt b/kotlin-result-coroutines/src/commonMain/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatching.kt
new file mode 100644
index 0000000..c63151e
--- /dev/null
+++ b/kotlin-result-coroutines/src/commonMain/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatching.kt
@@ -0,0 +1,4 @@
+package com.github.michaelbull.result.coroutines
+
+class RunSuspendCatching {
+}
diff --git a/kotlin-result-coroutines/src/jvmTest/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatchingTest.kt b/kotlin-result-coroutines/src/jvmTest/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatchingTest.kt
new file mode 100644
index 0000000..b244ad6
--- /dev/null
+++ b/kotlin-result-coroutines/src/jvmTest/kotlin/com/github/michaelbull/result/coroutines/RunSuspendCatchingTest.kt
@@ -0,0 +1,11 @@
+package com.github.michaelbull.result.coroutines
+
+import kotlin.test.Test
+
+class RunSuspendCatchingTest {
+
+    @Test
+    fun propogatesCoroutineCancellation() {
+        val testDispatcher = TestCoroutineDispatcher()
+    }
+}
diff --git a/kotlin-result/src/commonMain/kotlin/com/github/michaelbull/result/ThrowIfUnless.kt b/kotlin-result/src/commonMain/kotlin/com/github/michaelbull/result/ThrowIfUnless.kt
index ad93c40..087e6ad 100644
--- a/kotlin-result/src/commonMain/kotlin/com/github/michaelbull/result/ThrowIfUnless.kt
+++ b/kotlin-result/src/commonMain/kotlin/com/github/michaelbull/result/ThrowIfUnless.kt
@@ -1,5 +1,8 @@
 package com.github.michaelbull.result
 
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
+
 /**
  * If the [Result] is [Err] and contains a [Throwable], throws the [error][Err.error]
  * if the [predicate] returns true.
@@ -8,8 +11,10 @@ package com.github.michaelbull.result
  */
 public inline fun <V : Any?, E : Throwable> Result<V, E>.throwIf(
     predicate: (E) -> Boolean
-): Result<V, E> =
-    onFailure { e -> if (predicate(e)) throw e }
+): Result<V, E> {
+    contract { callsInPlace(predicate, InvocationKind.AT_MOST_ONCE)  }
+    return onFailure { e -> if (predicate(e)) throw e }
+}
 
 /**
  * If the [Result] is [Err] and contains a [Throwable], throws the [error][Err.error]