Added the OptionAssert

Author: rcardin

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

@@ -0,0 +1,17 @@
+package `in`.rcard.assertj.arrowcore
+
+import arrow.core.Option
+import org.assertj.core.api.AbstractObjectAssert
+
+/**
+ * Assertions for [Option].
+ *
+ * @param SELF  the "self" type of this assertion class.
+ * @param VALUE type of the value contained in the [Option].
+ * @author Riccardo Cardin
+ */
+abstract class AbstractOptionAssert<
+    SELF : AbstractOptionAssert<SELF, VALUE>, VALUE : Any,
+    >(
+    option: Option<VALUE>?,
+) : AbstractObjectAssert<SELF, Option<VALUE>>(option, AbstractOptionAssert::class.java)

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

@@ -0,0 +1,11 @@
+package `in`.rcard.assertj.arrowcore
+
+import arrow.core.Option
+
+class OptionAssert<VALUE : Any>(option: Option<VALUE>?) :
+    AbstractOptionAssert<OptionAssert<VALUE>, VALUE>(option) {
+    companion object {
+        fun <VALUE : Any> assertThat(option: Option<VALUE>?): OptionAssert<VALUE> =
+            OptionAssert(option)
+    }
+}

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

@@ -0,0 +1,29 @@
+package `in`.rcard.assertj.arrowcore
+
+import arrow.core.Option
+import arrow.core.some
+import org.assertj.core.api.BDDAssertions.then
+import org.junit.jupiter.api.Test
+
+class OptionAssert_assertThat_Test {
+
+    @Test
+    fun `should create an assertion instance when given object is not null`() {
+        // GIVEN
+        val someValue = 42.some()
+        // WHEN
+        val assertion = OptionAssert.assertThat<Any>(someValue)
+        // THEN
+        then(assertion).isNotNull.isInstanceOf(OptionAssert::class.java)
+    }
+
+    @Test
+    fun `should create an assertion instance when given object is null`() {
+        // GIVEN
+        val someNullValue: Option<Nothing>? = null
+        // WHEN
+        val assertion = OptionAssert.assertThat(someNullValue)
+        // THEN
+        then(assertion).isNotNull.isInstanceOf(OptionAssert::class.java)
+    }
+}