[JENKINS-47347] accept an optional pretty parameter for writeJSON step

src/main/java/org/jenkinsci/plugins/pipeline/utility/steps/json/WriteJSONStep.java

@@ -29,6 +29,7 @@
 import hudson.Extension;
 import hudson.Util;
 import net.sf.json.JSON;
+import org.kohsuke.stapler.DataBoundSetter;
 
 /**
  * Writes a {@link JSON} object to file in the current working directory.
@@ -39,6 +40,7 @@ public class WriteJSONStep extends AbstractStepImpl {
 
     private final String file;
     private final JSON json;
+    private int pretty = 0;
 
     @DataBoundConstructor
     public WriteJSONStep(String file, JSON json) {
@@ -64,6 +66,26 @@ public JSON getJson() {
         return json;
     }
 
+    /**
+     * Return the number of spaces used to prettify the JSON dump.
+     *
+     * @return a int
+     */
+    public int getPretty() {
+        return pretty;
+    }
+
+    /**
+     * Indents to use if the JSON should be pretty printed.
+     * A greater than zero integer will do so.
+     *
+     * @param pretty the indent size
+     */
+    @DataBoundSetter
+    void setPretty(int pretty) {
+        this.pretty = pretty;
+    }
+
     @Extension
     public static class DescriptorImpl extends AbstractStepDescriptorImpl {
 

src/main/java/org/jenkinsci/plugins/pipeline/utility/steps/json/WriteJSONStepExecution.java

@@ -72,7 +72,11 @@ protected Void run() throws Exception {
         }
 
         try (OutputStreamWriter writer = new OutputStreamWriter(path.write())) {
-            step.getJson().write(writer);
+            if (step.getPretty() > 0) {
+                writer.write(step.getJson().toString(step.getPretty()));
+            } else {
+                step.getJson().write(writer);
+            }
         }
         return null;
     }

src/main/resources/org/jenkinsci/plugins/pipeline/utility/steps/json/WriteJSONStep/help.html

@@ -44,5 +44,7 @@
 def input = readJSON file: 'myfile.json'
 //Do some manipulation
 writeJSON file: 'output.json', json: input
+// or pretty print it, indented with a configurable number of spaces
+writeJSON file: 'output.json', json: input, pretty: 4
 	</pre></code>
 </p>

src/test/java/org/jenkinsci/plugins/pipeline/utility/steps/conf/json/WriteJSONStepTest.java

@@ -29,6 +29,7 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 
@@ -60,6 +61,39 @@ public class WriteJSONStepTest {
     @Rule
     public TemporaryFolder temp = new TemporaryFolder();
 
+    @Test
+    public void writeFilePretty() throws Exception {
+        File output = temp.newFile();
+
+        WorkflowJob p = j.jenkins.createProject(WorkflowJob.class, "p");
+        p.setDefinition(new CpsFlowDefinition(
+                "node {\n" +
+                        " def json = readJSON text: '{\"a\": {\"1\": true,\"2\": 2}}' \n" +
+                        " writeJSON file: '" + FilenameTestsUtils.toPath(output) + "', json: json, pretty: 4\n" +
+                        "}", true));
+        j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+
+        String lines = new String(Files.readAllBytes(Paths.get(output.toURI())), StandardCharsets.UTF_8);
+        assertThat(lines.split("\r\n|\r|\n").length, equalTo(4));
+
+    }
+
+    @Test
+    public void writeFilePrettyEmpty() throws Exception {
+        File output = temp.newFile();
+
+        WorkflowJob p = j.jenkins.createProject(WorkflowJob.class, "p");
+        p.setDefinition(new CpsFlowDefinition(
+                "node {\n" +
+                        " def json = readJSON text: '{}' \n" +
+                        " writeJSON file: '" + FilenameTestsUtils.toPath(output) + "', json: json, pretty: 4\n" +
+                        "}", true));
+        j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+
+        String lines = new String(Files.readAllBytes(Paths.get(output.toURI())), StandardCharsets.UTF_8);
+        assertThat(lines.split("\r\n|\r|\n").length, equalTo(1));
+    }
+
     @Test
     public void writeFile() throws Exception {
         int elements = 3;