Handle JSON with Array as root (#1585)

Author: nedtwigg

CHANGES.md

@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Fixed
+* `JacksonJsonFormatterFunc` handles json files with an Array as root. ([#1585](https://github.com/diffplug/spotless/pull/1585))
 
 ## [2.35.0] - 2023-02-10
 ### Added

lib/src/jackson/java/com/diffplug/spotless/glue/json/AJacksonFormatterFunc.java

@@ -16,7 +16,6 @@
 package com.diffplug.spotless.glue.json;
 
 import java.io.IOException;
-import java.util.Map;
 
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonProcessingException;
@@ -49,7 +48,7 @@ public String apply(String input) throws Exception {
 	protected String format(ObjectMapper objectMapper, String input) throws IllegalArgumentException, IOException {
 		try {
 			// ObjectNode is not compatible with SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS
-			Map objectNode = objectMapper.readValue(input, Map.class);
+			Object objectNode = objectMapper.readValue(input, inferType(input));
 			String output = objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(objectNode);
 
 			return output;
@@ -58,6 +57,13 @@ protected String format(ObjectMapper objectMapper, String input) throws IllegalA
 		}
 	}
 
+	/**
+	 *
+	 * @param input
+	 * @return the {@link Class} into which the String has to be deserialized
+	 */
+	protected abstract Class<?> inferType(String input);
+
 	/**
 	 * @return a {@link JsonFactory}. May be overridden to handle alternative formats.
 	 * @see <a href="https://github.com/FasterXML/jackson-dataformats-text">jackson-dataformats-text</a>

lib/src/jackson/java/com/diffplug/spotless/glue/json/JacksonJsonFormatterFunc.java

@@ -15,6 +15,9 @@
  */
 package com.diffplug.spotless.glue.json;
 
+import java.util.Collection;
+import java.util.Map;
+
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonFactoryBuilder;
 import com.fasterxml.jackson.core.JsonGenerator;
@@ -37,6 +40,15 @@ public JacksonJsonFormatterFunc(JacksonJsonConfig jacksonConfig) {
 		this.jacksonConfig = jacksonConfig;
 	}
 
+	@Override
+	protected Class<?> inferType(String input) {
+		if (input.trim().startsWith("[")) {
+			return Collection.class;
+		} else {
+			return Map.class;
+		}
+	}
+
 	/**
 	 * @return a {@link JsonFactory}. May be overridden to handle alternative formats.
 	 * @see <a href="https://github.com/FasterXML/jackson-dataformats-text">jackson-dataformats-text</a>

lib/src/jackson/java/com/diffplug/spotless/glue/yaml/JacksonYamlFormatterFunc.java

@@ -58,13 +58,18 @@ protected JsonFactory makeJsonFactory() {
 		return yamlFactoryBuilder.build();
 	}
 
+	@Override
+	protected Class<?> inferType(String input) {
+		return JsonNode.class;
+	}
+
 	@Override
 	protected String format(ObjectMapper objectMapper, String input) throws IllegalArgumentException, IOException {
 		try {
 			// https://stackoverflow.com/questions/25222327/deserialize-pojos-from-multiple-yaml-documents-in-a-single-file-in-jackson
 			// https://github.com/FasterXML/jackson-dataformats-text/issues/66#issuecomment-375328648
 			JsonParser yamlParser = objectMapper.getFactory().createParser(input);
-			List<JsonNode> documents = objectMapper.readValues(yamlParser, JsonNode.class).readAll();
+			List<?> documents = objectMapper.readValues(yamlParser, inferType(input)).readAll();
 
 			// https://github.com/FasterXML/jackson-dataformats-text/issues/66#issuecomment-554265055
 			// https://github.com/FasterXML/jackson-dataformats-text/issues/66#issuecomment-554265055

plugin-gradle/CHANGES.md

@@ -4,10 +4,11 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 
 ## [Unreleased]
 ### Added
-* Add `includeDraft` option, to include draft mutators from composite mutators ([#1574](https://github.com/diffplug/spotless/pull/1574))
+* `cleanthat` now has `includeDraft` option, to include draft mutators from composite mutators ([#1574](https://github.com/diffplug/spotless/pull/1574))
+### Fixed
+* `json { jackson()` can now handle `Array` as a root element. ([#1585](https://github.com/diffplug/spotless/pull/1585))
 ### Changes
-* Bump default `cleanthat` version to latest `2.2` -> `2.6` ([#1574](https://github.com/diffplug/spotless/pull/1574))
-* Bump default `cleanthat` version to latest `2.1` -> `2.2` ([#1569](https://github.com/diffplug/spotless/pull/1569))
+* Bump default `cleanthat` version to latest `2.1` -> `2.6` ([#1569](https://github.com/diffplug/spotless/pull/1569) and [#1574](https://github.com/diffplug/spotless/pull/1574))
 
 ## [6.15.0] - 2023-02-10
 ### Added

plugin-maven/CHANGES.md

@@ -3,11 +3,12 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Fixed
+* `<json><jackson>` can now handle `Array` as a root element. ([#1585](https://github.com/diffplug/spotless/pull/1585))
 ### Added
-* Add `includeDraft` option, to include draft mutators from composite mutators ([#XXX](https://github.com/diffplug/spotless/pull/XXX))
+* `cleanthat` added `includeDraft` option, to include draft mutators from composite mutators ([#XXX](https://github.com/diffplug/spotless/pull/XXX))
 ### Changes
-* Bump default `cleanthat` version to latest `2.2` -> `2.6` ([#1574](https://github.com/diffplug/spotless/pull/1574))
-* Bump default `cleanthat` version to latest `2.1` -> `2.2` ([#1569](https://github.com/diffplug/spotless/pull/1569))
+* Bump default `cleanthat` version to latest `2.1` -> `2.6` ([#1569](https://github.com/diffplug/spotless/pull/1569) and [#1574](https://github.com/diffplug/spotless/pull/1574))
 
 ## [2.33.0] - 2023-02-10
 ### Added

testlib/src/main/resources/json/singletonArrayAfter_Jackson.json

@@ -0,0 +1 @@
+[ 1, 2, 3, 4 ]

testlib/src/main/resources/json/singletonArrayBefore.json

@@ -1 +1 @@
-[ 1, 2, 3, 4 ]
+[ 1  , 2, 3, 4 ]

testlib/src/test/java/com/diffplug/spotless/json/JacksonJsonStepTest.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2021-2023 DiffPlug
+ *
+ * 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 com.diffplug.spotless.json;
+
+import org.junit.jupiter.api.Test;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.StepHarness;
+import com.diffplug.spotless.TestProvisioner;
+
+class JacksonJsonStepTest {
+
+	private static final int INDENT = 4;
+
+	private final FormatterStep step = JsonSimpleStep.create(INDENT, TestProvisioner.mavenCentral());
+	private final StepHarness stepHarness = StepHarness.forStep(step);
+
+	@Test
+	void canSetCustomIndentationLevel() {
+		FormatterStep step = JacksonJsonStep.create(TestProvisioner.mavenCentral());
+		StepHarness stepHarness = StepHarness.forStep(step);
+
+		String before = "json/singletonArrayBefore.json";
+		String after = "json/singletonArrayAfter_Jackson.json";
+		stepHarness.testResource(before, after);
+	}
+}