DATAJDBC-522 - Add Kotlin extensions for Criteria.

Adding Kotlin extensions for easier consumption of Criteria when using Kotlin.

Original pull request: #240.

spring-data-relational/pom.xml

@@ -71,6 +71,20 @@
 			<scope>test</scope>
 		</dependency>
 
+		<!-- DATAJDBC-522: Add Kotlin extensions for Criteria -->
+		<dependency>
+			<groupId>org.jetbrains.kotlin</groupId>
+			<artifactId>kotlin-stdlib</artifactId>
+			<optional>true</optional>
+		</dependency>
+
+		<dependency>
+			<groupId>io.mockk</groupId>
+			<artifactId>mockk</artifactId>
+			<version>${mockk}</version>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 
 </project>

spring-data-relational/src/main/kotlin/org/springframework/data/relational/core/query/CriteriaStepExtensions.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2019-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.relational.core.query
+
+/**
+ * Extension for [Criteria.CriteriaStep. is] providing a
+ * `isEquals(value)` variant.
+ *
+ * @author Juan Medina<jamedina@gmail.com>
+ */
+infix fun Criteria.CriteriaStep.isEquals(value: Any): Criteria =
+        `is`(value)
+
+/**
+ * Extension for [Criteria.CriteriaStep. in] providing a
+ * `isIn(value)` variant.
+ *
+ * @author Juan Medina<jamedina@gmail.com>
+ */
+fun Criteria.CriteriaStep.isIn(vararg value: Any): Criteria =
+        `in`(value)
+
+/**
+ * Extension for [Criteria.CriteriaStep. in] providing a
+ * `isIn(value)` variant.
+ *
+ * @author Juan Medina<jamedina@gmail.com>
+ */
+fun Criteria.CriteriaStep.isIn(values: Collection<Any>): Criteria =
+        `in`(values)

spring-data-relational/src/test/kotlin/org/springframework/data/relational/core/query/CriteriaStepExtensionsTests.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.relational.core.query
+
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+
+/**
+ * Unit tests for [Criteria.CriteriaStep] extensions.
+ *
+ * @author Juan Medina<jamedina@gmail.com>
+ */
+class CriteriaStepExtensionsTests {
+
+    @Test // DATAJDBC-522
+    fun eqIsCriteriaStep(){
+
+        val spec = mockk<Criteria.CriteriaStep>()
+        val criteria = mockk<Criteria>()
+
+        every { spec.`is`("test") } returns criteria
+
+        assertThat(spec isEquals "test").isEqualTo(criteria)
+
+        verify {
+            spec.`is`("test")
+        }
+    }
+
+    @Test // DATAJDBC-522
+    fun inVarargCriteriaStep() {
+
+        val spec = mockk<Criteria.CriteriaStep>()
+        val criteria = mockk<Criteria>()
+
+        every { spec.`in`(any() as Array<Any>) } returns criteria
+
+        assertThat(spec.isIn("test")).isEqualTo(criteria)
+
+        verify {
+            spec.`in`(arrayOf("test"))
+        }
+    }
+
+    @Test // DATAJDBC-522
+    fun inListCriteriaStep() {
+
+        val spec = mockk<Criteria.CriteriaStep>()
+        val criteria = mockk<Criteria>()
+
+        every { spec.`in`(listOf("test")) } returns criteria
+
+        assertThat(spec.isIn(listOf("test"))).isEqualTo(criteria)
+
+        verify {
+            spec.`in`(listOf("test"))
+        }
+    }
+}