[Core] Mark pending steps as failed in teamcity plugin

The teamcity plugin communicates test results to IntelliJ IDEA using teamcity
service messages[1]. Currently the teamcity plugin marks pending steps as
skipped rather then failed. This is inconsistent with the changes from #1960
in which pending steps are considered a test failure.

 1: https://www.jetbrains.com/help/teamcity/service-messages.html

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

@@ -48,6 +48,13 @@
 import static java.util.Collections.emptyList;
 import static java.util.stream.Collectors.joining;
 
+/**
+ * Outputs Teamcity services messages to std out.
+ *
+ * @see <a
+ *      href=https://www.jetbrains.com/help/teamcity/service-messages.html>TeamCity
+ *      - Service Messages</a>
+ */
 public class TeamCityPlugin implements EventListener {
 
     private static final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'hh:mm:ss.SSSZ");
@@ -250,22 +257,27 @@ private void printTestStepFinished(TestStepFinished event) {
         Throwable error = event.getResult().getError();
         Status status = event.getResult().getStatus();
         switch (status) {
-            case SKIPPED:
-                print(TEMPLATE_TEST_IGNORED, timeStamp, duration, error == null ? "Step skipped" : error.getMessage(),
-                    name);
+            case SKIPPED: {
+                String message = error == null ? "Step skipped" : error.getMessage();
+                print(TEMPLATE_TEST_IGNORED, timeStamp, duration, message, name);
                 break;
-            case PENDING:
-                print(TEMPLATE_TEST_IGNORED, timeStamp, duration, error == null ? "Step pending" : error.getMessage(),
-                    name);
+            }
+            case PENDING: {
+                String details = error == null ? "" : error.getMessage();
+                print(TEMPLATE_TEST_FAILED, timeStamp, duration, "Step pending", details, name);
                 break;
-            case UNDEFINED:
-                print(TEMPLATE_TEST_FAILED, timeStamp, duration, "Step undefined", getSnippets(currentTestCase), name);
+            }
+            case UNDEFINED: {
+                String snippets = getSnippets(currentTestCase);
+                print(TEMPLATE_TEST_FAILED, timeStamp, duration, "Step undefined", snippets, name);
                 break;
+            }
             case AMBIGUOUS:
-            case FAILED:
+            case FAILED: {
                 String details = extractStackTrace(error);
                 print(TEMPLATE_TEST_FAILED, timeStamp, duration, "Step failed", details, name);
                 break;
+            }
             default:
                 break;
         }

core/src/test/java/io/cucumber/core/plugin/TeamCityPluginTest.java

@@ -1,6 +1,7 @@
 package io.cucumber.core.plugin;
 
 import io.cucumber.core.backend.StubHookDefinition;
+import io.cucumber.core.backend.StubPendingException;
 import io.cucumber.core.backend.StubStepDefinition;
 import io.cucumber.core.backend.TestCaseState;
 import io.cucumber.core.feature.TestFeatureParser;
@@ -215,6 +216,28 @@ void should_print_error_message_for_undefined_steps() {
                 "##teamcity[testFailed timestamp = '1970-01-01T12:00:00.000+0000' duration = '0' message = 'Step undefined' details = 'You can implement this step and 1 other step(s)using the snippet(s) below:|n|ntest snippet 0|ntest snippet 1|n' name = 'first step']"));
     }
 
+    @Test
+    void should_print_error_message_for_pending_steps() {
+        Feature feature = TestFeatureParser.parse("path/test.feature", "" +
+                "Feature: feature name\n" +
+                "  Scenario: scenario name\n" +
+                "    Given first step\n" +
+                "    Given second step\n");
+
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        Runtime.builder()
+                .withFeatureSupplier(new StubFeatureSupplier(feature))
+                .withAdditionalPlugins(new TeamCityPlugin(new PrintStream(out)))
+                .withEventBus(new TimeServiceEventBus(fixed(EPOCH, of("UTC")), UUID::randomUUID))
+                .withBackendSupplier(
+                    new StubBackendSupplier(new StubStepDefinition("first step", new StubPendingException())))
+                .build()
+                .run();
+
+        assertThat(out, bytesContainsString("" +
+                "##teamcity[testFailed timestamp = '1970-01-01T12:00:00.000+0000' duration = '0' message = 'Step pending' details = 'TODO: implement me' name = 'first step']"));
+    }
+
     @Test
     void should_print_error_message_for_before_hooks() {
         Feature feature = TestFeatureParser.parse("path/test.feature", "" +