From a4c9ef926547c101bc6237febc2dc718020291c7 Mon Sep 17 00:00:00 2001
From: Nicolas Peltier <npeltier@adobe.com>
Date: Fri, 25 Sep 2020 17:44:30 +0200
Subject: [PATCH] GH-156 fix NPE for corner case + docs

---
 ...dobe.dx.domtagging.internal.Spacing.config |  0
 .../internal/AttributeServiceImpl.java        | 16 ++++++++-----
 .../internal/AttributeServiceImplTest.java    | 24 ++++++++++++++++++-
 3 files changed, 33 insertions(+), 7 deletions(-)
 create mode 100644 apps/docs/app/jcr_root/apps/dx-docs/configs/config/com.adobe.dx.domtagging.internal.Spacing.config

diff --git a/apps/docs/app/jcr_root/apps/dx-docs/configs/config/com.adobe.dx.domtagging.internal.Spacing.config b/apps/docs/app/jcr_root/apps/dx-docs/configs/config/com.adobe.dx.domtagging.internal.Spacing.config
new file mode 100644
index 00000000..e69de29b
diff --git a/bundles/core/src/main/java/com/adobe/dx/domtagging/internal/AttributeServiceImpl.java b/bundles/core/src/main/java/com/adobe/dx/domtagging/internal/AttributeServiceImpl.java
index e1d80b3b..921a33c9 100644
--- a/bundles/core/src/main/java/com/adobe/dx/domtagging/internal/AttributeServiceImpl.java
+++ b/bundles/core/src/main/java/com/adobe/dx/domtagging/internal/AttributeServiceImpl.java
@@ -24,6 +24,7 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -58,9 +59,10 @@ public class AttributeServiceImpl extends AbstractWorkerManager<AttributeWorker>
             if (worker != null) {
                 logger.debug("get attributes from worker {}", worker.getKey());
                 Map<String, String> workerMap = worker.getAttributes(request);
-                if (attributes == null) {
-                    attributes = workerMap;
-                } else {
+                if (workerMap != null){
+                    if (attributes == null) {
+                        attributes = new HashMap<>();
+                    }
                     attributes.putAll(workerMap);
                 }
             }
@@ -76,10 +78,12 @@ public class AttributeServiceImpl extends AbstractWorkerManager<AttributeWorker>
             if (worker != null) {
                 logger.debug("get classes from worker {}", worker.getKey());
                 Collection<String> workerClasses = worker.getClasses(request);
-                if (classes == null) {
-                    classes = new ArrayList<>();
+                if (workerClasses != null) {
+                    if (classes == null) {
+                        classes = new ArrayList<>();
+                    }
+                    classes.addAll(workerClasses);
                 }
-                classes.addAll(workerClasses);
             }
         }
         return classes != null ? String.join(SPACE, classes) : null;
diff --git a/bundles/core/src/test/java/com/adobe/dx/domtagging/internal/AttributeServiceImplTest.java b/bundles/core/src/test/java/com/adobe/dx/domtagging/internal/AttributeServiceImplTest.java
index 2d32c910..5b7860ac 100644
--- a/bundles/core/src/test/java/com/adobe/dx/domtagging/internal/AttributeServiceImplTest.java
+++ b/bundles/core/src/test/java/com/adobe/dx/domtagging/internal/AttributeServiceImplTest.java
@@ -84,7 +84,7 @@ public String getKey() {
     void setup() {
         List<Breakpoint> breakpoints = ResponsivePropertiesImplTest.initResponsiveConfiguration(context);
         String someComp = CONTENT_ROOT + "/comp";
-        final String[] array = new String[] {"worker1", "worker2"};
+        final String[] array = new String[] {"worker1", "worker2", "workerNull"};
         context.build().resource(CONFIG_ROOTS  + "/apps/foo/bar",  "attributeWorkers", array);
         context.build().resource(someComp, "sling:resourceType", "foo/bar");
         context.currentResource(someComp);
@@ -114,4 +114,26 @@ public void testTwoWorker() {
         assertTrue(CollectionUtils.isEqualCollection(Arrays.asList("11", "12", "21", "22"), service.getAttributes(context.request()).keySet()));
         assertEquals("c1 c2", service.getClassesString(context.request()));
     }
+
+    @Test
+    public void testNullWorker() {
+        service.bindWorker(new AttributeWorker() {
+            @Override
+            public Map<String, String> getAttributes(SlingHttpServletRequest request) {
+                return null;
+            }
+
+            @Override
+            public Collection<String> getClasses(SlingHttpServletRequest request) {
+                return null;
+            }
+
+            @Override
+            public String getKey() {
+                return "workerNull";
+            }
+        });
+        assertNull(service.getClassesString(context.request()));
+        assertNull(service.getAttributes(context.request()));
+    }
 }
\ No newline at end of file