[Core] Indent write events in PrettyFormatter (#1809)

Closes: #1809

Squashed commit of the following:

commit d77448dd64e8432b70b3a0c44b7e46c7b61f1b36
Merge: be92824 cb57d8c
Author: M.P. Korstanje <[email protected]>
Date:   Thu Oct 17 18:24:08 2019 +0200

    Merge branch 'indent' of https://github.com/alexandreonterroso/cucumber-jvm into alexandreonterroso-indent

commit cb57d8c
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 17:46:57 2019 +0200

    Indent with spaces

commit 819ec9b
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 15:48:55 2019 +0200

    indentation

commit 4dfb464
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 15:16:06 2019 +0200

    Correct indentation

commit 0d4abbe
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 15:11:10 2019 +0200

    Avoid repetition

commit 0687c9a
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 15:01:27 2019 +0200

    Auto-closeable buffer

commit beb16b2
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 14:54:48 2019 +0200

    Add some indentation

commit 00c01db
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 14:54:20 2019 +0200

    Add some indentation

commit 8d35ec4
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 14:53:13 2019 +0200

    Multi-lines Strings

commit 530265b
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 14:12:31 2019 +0200

    Add some indentation

commit f59ee85
Author: alexandre.monterroso <[email protected]>
Date:   Thu Oct 17 14:09:58 2019 +0200

    Add some indentation

Author: mpkorstanje

core/src/main/java/io/cucumber/core/plugin/PrettyFormatter.java

@@ -7,6 +7,7 @@
 import gherkin.ast.ScenarioOutline;
 import gherkin.ast.Step;
 import gherkin.ast.Tag;
+import io.cucumber.core.exception.CucumberException;
 import io.cucumber.plugin.ColorAware;
 import io.cucumber.plugin.EventListener;
 import io.cucumber.plugin.event.Argument;
@@ -22,7 +23,10 @@
 import io.cucumber.plugin.event.TestStepStarted;
 import io.cucumber.plugin.event.WriteEvent;
 
+import java.io.BufferedReader;
+import java.io.IOException;
 import java.io.PrintWriter;
+import java.io.StringReader;
 import java.io.StringWriter;
 import java.net.URI;
 import java.util.List;
@@ -34,6 +38,7 @@ public final class PrettyFormatter implements EventListener, ColorAware {
     private static final String SCENARIO_INDENT = "  ";
     private static final String STEP_INDENT = "    ";
     private static final String EXAMPLES_INDENT = "    ";
+    private static final String STEP_SCENARIO_INDENT = "      ";
     private final TestSourcesModel testSources = new TestSourcesModel();
     private final NiceAppendable out;
     private Formats formats;
@@ -100,7 +105,17 @@ private void handleTestStepFinished(TestStepFinished event) {
     }
 
     private void handleWrite(WriteEvent event) {
-        out.println(event.getText());
+        out.println();
+        try(BufferedReader lines = new BufferedReader(new StringReader(event.getText()))) {
+            String line;
+            while ((line = lines.readLine()) != null) {
+                out.println(STEP_SCENARIO_INDENT + line);
+            }
+        } catch (IOException e) {
+            throw new CucumberException(e);
+        }
+        out.println();
+
     }
 
     private void finishReport() {

examples/java-calculator/src/test/java/io/cucumber/examples/java/RpnCalculatorSteps.java

@@ -43,7 +43,7 @@ public void before(Scenario scenario) {
 
     @After
     public void after(Scenario scenario) {
-        // result.write("HELLLLOO");
+        // scenario.write("HELLLLOO");
     }
 
     @Given("the previous entries:")

examples/java-calculator/src/test/java/io/cucumber/examples/java/RunCucumberTest.java

@@ -5,7 +5,7 @@
 import org.junit.runner.RunWith;
 
 @RunWith(Cucumber.class)
-@CucumberOptions(plugin = {"json:target/cucumber-report.json"})
+@CucumberOptions(plugin = {"json:target/cucumber-report.json", "pretty"})
 public class RunCucumberTest {
 
 }