Add Kotlin support for RestTestClient

Author: lukas-krecan

json-unit-kotest/pom.xml

@@ -143,7 +143,7 @@
             <plugin>
                 <groupId>org.jetbrains.dokka</groupId>
                 <artifactId>dokka-maven-plugin</artifactId>
-                <version>2.0.0</version>
+                <version>2.1.0-Beta</version>
                 <executions>
                     <execution>
                         <phase>package</phase>

json-unit-spring/src/main/java/net/javacrumbs/jsonunit/spring/CharsetUtils.java

@@ -0,0 +1,16 @@
+package net.javacrumbs.jsonunit.spring;
+
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import org.jspecify.annotations.Nullable;
+import org.springframework.http.MediaType;
+
+class CharsetUtils {
+    static Charset getCharset(@Nullable MediaType contentType) {
+        if (contentType != null && contentType.getCharset() != null) {
+            return contentType.getCharset();
+        } else {
+            return StandardCharsets.UTF_8;
+        }
+    }
+}

json-unit-spring/src/main/java/net/javacrumbs/jsonunit/spring/RestTestClientJsonMatcher.java

@@ -1,11 +1,11 @@
 package net.javacrumbs.jsonunit.spring;
 
-import java.nio.charset.Charset;
+import static net.javacrumbs.jsonunit.spring.RestTestClientUtils.getContentAsString;
+
 import java.util.function.Consumer;
 import java.util.function.Function;
 import net.javacrumbs.jsonunit.core.Configuration;
 import net.javacrumbs.jsonunit.core.internal.matchers.InternalMatcher;
-import org.jspecify.annotations.Nullable;
 import org.springframework.test.web.servlet.client.EntityExchangeResult;
 
 /**
@@ -51,15 +51,5 @@ private JsonUnitWebTestClientMatcher(
         public void accept(EntityExchangeResult<byte[]> result) {
             doMatch(getContentAsString(result));
         }
-
-        private static @Nullable String getContentAsString(EntityExchangeResult<byte[]> result) {
-            Charset charset = getCharset(result);
-            byte[] responseBody = result.getResponseBody();
-            return responseBody != null ? new String(responseBody, charset) : null;
-        }
-
-        private static Charset getCharset(EntityExchangeResult<byte[]> result) {
-            return Utils.getCharset(result.getResponseHeaders().getContentType());
-        }
     }
 }

json-unit-spring/src/main/java/net/javacrumbs/jsonunit/spring/RestTestClientUtils.java

@@ -0,0 +1,21 @@
+package net.javacrumbs.jsonunit.spring;
+
+import java.nio.charset.Charset;
+import org.jspecify.annotations.Nullable;
+import org.springframework.test.web.servlet.client.EntityExchangeResult;
+
+class RestTestClientUtils {
+    static @Nullable String getContentAsString(EntityExchangeResult<byte[]> result) {
+        Charset charset = getCharset(result);
+        byte[] responseBody = result.getResponseBody();
+        if (responseBody != null) {
+            return new String(responseBody, charset);
+        } else {
+            return null;
+        }
+    }
+
+    private static Charset getCharset(EntityExchangeResult<byte[]> result) {
+        return CharsetUtils.getCharset(result.getResponseHeaders().getContentType());
+    }
+}

json-unit-spring/src/main/java/net/javacrumbs/jsonunit/spring/WebTestClientJsonMatcher.java

@@ -1,6 +1,6 @@
 package net.javacrumbs.jsonunit.spring;
 
-import static net.javacrumbs.jsonunit.spring.Utils.getContentAsString;
+import static net.javacrumbs.jsonunit.spring.WebTestClientUtils.getContentAsString;
 
 import java.util.function.Consumer;
 import java.util.function.Function;

json-unit-spring/src/main/java/net/javacrumbs/jsonunit/spring/Utils.java renamed to json-unit-spring/src/main/java/net/javacrumbs/jsonunit/spring/WebTestClientUtils.java

@@ -1,12 +1,10 @@
 package net.javacrumbs.jsonunit.spring;
 
 import java.nio.charset.Charset;
-import java.nio.charset.StandardCharsets;
 import org.jspecify.annotations.Nullable;
-import org.springframework.http.MediaType;
 import org.springframework.test.web.reactive.server.EntityExchangeResult;
 
-class Utils {
+class WebTestClientUtils {
     static @Nullable String getContentAsString(EntityExchangeResult<byte[]> result) {
         Charset charset = getCharset(result);
         byte[] responseBody = result.getResponseBody();
@@ -18,14 +16,6 @@ class Utils {
     }
 
     private static Charset getCharset(EntityExchangeResult<byte[]> result) {
-        return getCharset(result.getResponseHeaders().getContentType());
-    }
-
-    static Charset getCharset(@Nullable MediaType contentType) {
-        if (contentType != null && contentType.getCharset() != null) {
-            return contentType.getCharset();
-        } else {
-            return StandardCharsets.UTF_8;
-        }
+        return CharsetUtils.getCharset(result.getResponseHeaders().getContentType());
     }
 }

json-unit-spring/src/main/kotlin/net/javacrumbs/jsonunit/spring/RestTestClientJsonMatcherDsl.kt

@@ -0,0 +1,21 @@
+package net.javacrumbs.jsonunit.spring
+
+import net.javacrumbs.jsonunit.assertj.JsonAssert
+import net.javacrumbs.jsonunit.assertj.JsonAssertions
+import net.javacrumbs.jsonunit.spring.RestTestClientUtils.getContentAsString
+import net.javacrumbs.jsonunit.spring.WebTestClientUtils.getContentAsString
+import org.springframework.test.web.servlet.client.RestTestClient
+
+/**
+ * Example usage:
+ * ```
+ * client.get().uri(path).accept(APPLICATION_JSON)
+ * .exchange()
+ * .jsonContent { isEqualTo(CORRECT_JSON) }
+ * ```
+ */
+fun RestTestClient.BodyContentSpec.jsonContent(
+    matcher: JsonAssert.ConfigurableJsonAssert.() -> Unit
+): RestTestClient.BodyContentSpec = consumeWith { result ->
+    matcher(JsonAssertions.assertThatJson(getContentAsString(result)))
+}

json-unit-spring/src/main/kotlin/net/javacrumbs/jsonunit/spring/WebTestClientJsonMatcherDsl.kt

@@ -2,7 +2,7 @@ package net.javacrumbs.jsonunit.spring
 
 import net.javacrumbs.jsonunit.assertj.JsonAssert
 import net.javacrumbs.jsonunit.assertj.JsonAssertions
-import net.javacrumbs.jsonunit.spring.Utils.getContentAsString
+import net.javacrumbs.jsonunit.spring.WebTestClientUtils.getContentAsString
 import org.springframework.test.web.reactive.server.WebTestClient
 
 /**

json-unit-spring/src/test/kotlin/net/javacrumbs/jsonunit/spring/testit/KotlinRestTestClientTest.kt

@@ -0,0 +1,125 @@
+/**
+ * Copyright 2009-2019 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
+ *
+ * http://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 net.javacrumbs.jsonunit.spring.testit
+
+import net.javacrumbs.jsonunit.core.listener.Difference
+import net.javacrumbs.jsonunit.core.listener.DifferenceContext
+import net.javacrumbs.jsonunit.core.listener.DifferenceListener
+import net.javacrumbs.jsonunit.spring.jsonContent
+import net.javacrumbs.jsonunit.spring.testit.demo.ExampleController
+import net.javacrumbs.jsonunit.spring.testit.demo.ExampleController.CORRECT_JSON
+import net.javacrumbs.jsonunit.spring.testit.demo.SpringConfig
+import org.assertj.core.api.Assertions.assertThatThrownBy
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+import org.mockito.ArgumentMatchers.any
+import org.mockito.Mockito.mock
+import org.mockito.Mockito.verify
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.http.MediaType.APPLICATION_JSON
+import org.springframework.test.context.ContextConfiguration
+import org.springframework.test.context.junit.jupiter.SpringExtension
+import org.springframework.test.context.web.WebAppConfiguration
+import org.springframework.test.web.servlet.client.RestTestClient
+import org.springframework.web.context.WebApplicationContext
+
+@ExtendWith(SpringExtension::class)
+@ContextConfiguration(classes = [SpringConfig::class])
+@WebAppConfiguration
+internal class KotlinRestTestClientTest {
+    @Autowired lateinit var wac: WebApplicationContext
+
+    lateinit var client: RestTestClient
+
+    @BeforeEach
+    fun setUp() {
+        client = RestTestClient.bindToApplicationContext(wac).build()
+    }
+
+    @Test
+    fun shouldPassIfEqualsWithProduces() {
+        exec("/sampleProduces")
+            .expectBody()
+            .jsonContent { isEqualTo(CORRECT_JSON) }
+            .jsonContent { node("result.string").isString().isEqualTo("stringValue") }
+    }
+
+    @Test
+    fun shouldPassIfEqualsWithIsoEncoding() {
+        exec("/sampleIso").expectBody().jsonContent { node("result").isEqualTo(ExampleController.ISO_VALUE) }
+    }
+
+    @Test
+    fun shouldPassIfEquals() {
+        exec().expectBody().jsonContent { isEqualTo(CORRECT_JSON) }
+    }
+
+    @Test
+    fun isEqualToShouldFailIfDoesNotEqual() {
+        val listener = mock(DifferenceListener::class.java)
+        assertThatThrownBy {
+                exec().expectBody().jsonContent {
+                    withDifferenceListener(listener).isEqualTo(CORRECT_JSON.replace("stringValue", "stringValue2"))
+                }
+            }
+            .hasMessageStartingWith(
+                """
+                JSON documents are different:
+                Different value found in node "result.string", expected: <"stringValue2"> but was: <"stringValue">.
+
+                """
+                    .trimIndent()
+            )
+        verify(listener).diff(any(Difference::class.java), any(DifferenceContext::class.java))
+    }
+
+    @Test
+    fun isEqualToInNodeFailIfDoesNotEqual() {
+        assertThatThrownBy {
+                exec().expectBody().jsonContent { node("result.string").isString().isEqualTo("stringValue2") }
+            }
+            .hasMessage(
+                "[Different value found in node \"result.string\"] \n" +
+                    "expected: \"stringValue2\"\n" +
+                    " but was: \"stringValue\""
+            )
+    }
+
+    @Test
+    fun errorOnEmptyResponse() {
+        assertThatThrownBy { exec("/empty").expectBody().jsonContent { isObject() } }
+            .hasMessageStartingWith("Node \"\" has invalid type, expected: <object> but was: <null>.")
+    }
+
+    @Test
+    fun isNullShouldPassOnNull() {
+        exec().expectBody().jsonContent { node("result.null").isNull() }
+    }
+
+    @Test
+    fun isNullShouldFailOnNonNull() {
+        assertThatThrownBy { exec().expectBody().jsonContent { node("result.string").isNull() } }
+            .hasMessageStartingWith(
+                "Node \"result.string\" has invalid type, expected: <null> but was: <\"stringValue\">."
+            )
+    }
+
+    private fun exec(path: String = "/sample"): RestTestClient.ResponseSpec {
+        try {
+            return client.get().uri(path).accept(APPLICATION_JSON).exchange().expectStatus().isOk()
+        } catch (e: Exception) {
+            throw IllegalStateException(e)
+        }
+    }
+}