Add 'orEmpty' convenience function to Option (#58)

block · Sep 20, 2023 · a65ef0d · a65ef0d
1 parent e728c39
commit a65ef0d
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Showing 3 changed files with 17 additions and 0 deletions.
diff --git a/lib/api/lib.api b/lib/api/lib.api
@@ -240,6 +240,7 @@ public final class app/cash/quiver/extensions/OptionKt {
 	public static final fun forEach (Larrow/core/Option;Lkotlin/jvm/functions/Function1;)V
 	public static final fun ifAbsent (Larrow/core/Option;Lkotlin/jvm/functions/Function0;)V
 	public static final fun or (Larrow/core/Option;Larrow/core/Option;)Larrow/core/Option;
+	public static final fun orEmpty (Larrow/core/Option;Lkotlin/jvm/functions/Function1;)Ljava/lang/String;
 	public static final fun toValidatedNel (Larrow/core/Option;Lkotlin/jvm/functions/Function0;)Larrow/core/Validated;
 	public static final fun unit (Larrow/core/Option;)Larrow/core/Option;
 }

diff --git a/lib/src/main/kotlin/app/cash/quiver/extensions/Option.kt b/lib/src/main/kotlin/app/cash/quiver/extensions/Option.kt
@@ -6,6 +6,7 @@ import arrow.core.None
 import arrow.core.Option
 import arrow.core.Some
 import arrow.core.ValidatedNel
+import arrow.core.getOrElse
 import arrow.core.nonEmptyListOf
 
 /**
@@ -41,3 +42,10 @@ infix fun <T> Option<T>.or(other: Option<T>): Option<T> = when (this) {
   is Some -> this
   is None -> other
 }
+
+/**
+ * Will return an empty string if the Optional value supplied is None
+ */
+fun <T> Option<T>.orEmpty(f: (T) -> String): String = this.map(f).getOrElse { "" }
+
+
diff --git a/lib/src/test/kotlin/app/cash/quiver/extensions/OptionTest.kt b/lib/src/test/kotlin/app/cash/quiver/extensions/OptionTest.kt
@@ -29,4 +29,12 @@ class OptionTest : StringSpec({
       None.or(other) shouldBe other
     }
   }
+
+  "orEmpty returns an empty string if used on a None" {
+    None.orEmpty { "I am an useless string " } shouldBe ""
+  }
+
+  "orEmpty returns the string supplied if value is Some" {
+    "apples".some().orEmpty { "I wanna eat $it" } shouldBe "I wanna eat apples"
+  }
 })