✨ (Core): Add the enum forgeries

xgouchet · Dec 9, 2019 · 22d19d4 · 22d19d4
1 parent efd123c
commit 22d19d4
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Showing 2 changed files with 69 additions and 5 deletions.
diff --git a/core/src/main/kotlin/fr/xgouchet/elmyr/Forge.kt b/core/src/main/kotlin/fr/xgouchet/elmyr/Forge.kt
@@ -72,11 +72,10 @@ open class Forge {
         @Suppress("UNCHECKED_CAST")
         val strictMatch = factories[clazz] as? ForgeryFactory<T>
 
-        @Suppress("IfThenToElvis")
-        return if (strictMatch == null) {
-            getSubclassForgery(clazz)
-        } else {
-            strictMatch.getForgery(this)
+        return when {
+            clazz.isEnum -> anElementFrom(*clazz.enumConstants)
+            strictMatch == null -> getSubclassForgery(clazz)
+            else -> strictMatch.getForgery(this)
         }
     }
 
@@ -932,6 +931,29 @@ open class Forge {
 
     // endregion
 
+    // region Enum
+
+    /**
+     * @param enumClass an Enum class
+     * @param exclude a list of enum constants to exclude from the values
+     * @return an element “randomly” picked in the enum values
+     */
+    @Suppress("SpreadOperator")
+    @JvmOverloads
+    fun <E : Enum<E>> aValueFrom(
+        enumClass: Class<E>,
+        exclude: Collection<E> = emptyList()
+    ): E {
+        val chooseFrom = if (exclude.isNotEmpty()) {
+            enumClass.enumConstants.subtract(exclude).toList()
+        } else {
+            enumClass.enumConstants.toList()
+        }
+        return anElementFrom(chooseFrom)
+    }
+
+    // endregion
+
     // region Nullable
 
     /**

diff --git a/core/src/test/kotlin/fr/xgouchet/elmyr/ForgeCollectionSpek.kt b/core/src/test/kotlin/fr/xgouchet/elmyr/ForgeCollectionSpek.kt
@@ -1,5 +1,6 @@
 package fr.xgouchet.elmyr
 
+import java.time.Month
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.KotlinAssertions.assertThat as assertThatK
 import org.spekframework.spek2.Spek
@@ -159,6 +160,47 @@ class ForgeCollectionSpek : Spek({
 
         // endregion
 
+        // region Choosing from an enum
+
+        context("forging value from an enum") {
+            it("selects a value from an enum class") {
+                repeat(testRepeatCountSmall) {
+                    val value = forge.aValueFrom(Month::class.java)
+
+                    assertThat(value).isInstanceOf(Month::class.java)
+                }
+            }
+
+            it("selects a value from an enum class") {
+                repeat(testRepeatCountSmall) {
+                    val value = forge.getForgery(Month::class.java)
+
+                    assertThat(value).isInstanceOf(Month::class.java)
+                }
+            }
+
+            it("selects a value from an enum class") {
+                repeat(testRepeatCountSmall) {
+                    val value = forge.getForgery<Month>()
+
+                    assertThat(value).isInstanceOf(Month::class.java)
+                }
+            }
+
+            it("selects a value from an enum class with excluded values") {
+                repeat(testRepeatCountSmall) {
+                    val excluded = forge.aList(3) { aValueFrom(Month::class.java) }
+                    val value = forge.aValueFrom(Month::class.java, excluded)
+
+                    assertThat(value)
+                            .isInstanceOf(Month::class.java)
+                            .isNotIn(excluded)
+                }
+            }
+        }
+
+        //endregion
+
         // region Transforming collections
 
         context("forging sublists") {