Merge pull request #28 from rcardin/16-add-a-get-method-to-the-assertions-on-optiont

Added get() method to OptionAssert

Author: rcardin

src/main/kotlin/in/rcard/assertj/arrowcore/AbstractOptionAssert.kt

@@ -6,6 +6,7 @@ import `in`.rcard.assertj.arrowcore.errors.OptionShouldBePresent.Companion.shoul
 import `in`.rcard.assertj.arrowcore.errors.OptionShouldContain.Companion.shouldContain
 import `in`.rcard.assertj.arrowcore.errors.OptionShouldContainInstanceOf.Companion.shouldContainInstanceOf
 import org.assertj.core.api.AbstractObjectAssert
+import org.assertj.core.api.Assertions
 import org.assertj.core.internal.ComparisonStrategy
 import org.assertj.core.internal.StandardComparisonStrategy
 
@@ -26,16 +27,6 @@ abstract class AbstractOptionAssert<
 
     private val comparisonStrategy: ComparisonStrategy = StandardComparisonStrategy.instance()
 
-    /**
-     * Verifies that there is a value present in the actual [Option].
-     *
-     * @return this assertion object.
-     */
-    fun isDefined(): SELF {
-        assertValueIsPresent()
-        return myself
-    }
-
     /**
      * Verifies that the actual [Option] is empty.
      *
@@ -96,12 +87,38 @@ abstract class AbstractOptionAssert<
      * @return this assertion object.
      * @since 0.1.0
      */
+    @Deprecated(
+        "hasValueSatisfying can be replaced using the method get() and chaining assertions on the returned object.",
+        ReplaceWith("get().satisfies(requirement)"),
+    )
     fun hasValueSatisfying(requirement: (VALUE) -> Unit): SELF {
         assertValueIsPresent()
         actual.onSome { requirement(it) }
         return myself
     }
 
+    /**
+     * Verifies that the actual [Option] is not null and not empty and returns an Object assertion that allows
+     * chaining (object) assertions on the optional value.
+     *
+     * @since 0.2.0
+     * @return a new [AbstractObjectAssert] for assertions chaining on the value of the [Option].
+     */
+    fun get(): AbstractObjectAssert<*, VALUE> {
+        isDefined()
+        return Assertions.assertThat(actual.getOrNull())
+    }
+
+    /**
+     * Verifies that there is a value present in the actual [Option].
+     *
+     * @return this assertion object.
+     */
+    fun isDefined(): SELF {
+        assertValueIsPresent()
+        return myself
+    }
+
     private fun assertValueIsPresent() {
         isNotNull
         if (actual.isNone()) throwAssertionError(shouldBePresent())

src/test/kotlin/in/rcard/assertj/arrowcore/OptionAssert_get_Test.kt

@@ -0,0 +1,35 @@
+package `in`.rcard.assertj.arrowcore
+
+import arrow.core.None
+import arrow.core.Option
+import arrow.core.some
+import `in`.rcard.assertj.arrowcore.OptionAssert.Companion.assertThat
+import `in`.rcard.assertj.arrowcore.errors.OptionShouldBePresent.Companion.shouldBePresent
+import org.assertj.core.api.Assertions
+import org.assertj.core.util.FailureMessages
+import org.junit.jupiter.api.Test
+
+internal class OptionAssert_get_Test {
+
+    @Test
+    internal fun `should return a valid Object assert if the Option is not empty`() {
+        val some: Option<String> = "42".some()
+        assertThat(some).get().isEqualTo("42")
+    }
+
+    @Test
+    internal fun `should fail if the Option is empty`() {
+        val none: Option<String> = None
+        Assertions.assertThatThrownBy { assertThat(none).get() }
+            .isInstanceOf(AssertionError::class.java)
+            .hasMessage(shouldBePresent().create())
+    }
+
+    @Test
+    internal fun `should fail if the Option is null`() {
+        val nullOption: Option<String>? = null
+        Assertions.assertThatThrownBy { assertThat(nullOption).get() }
+            .isInstanceOf(AssertionError::class.java)
+            .hasMessage(FailureMessages.actualIsNull())
+    }
+}