fixes #282

Author: anshooarora

src/main/java/com/aventstack/extentreports/model/context/NamedAttributeContextManager.java

@@ -20,7 +20,7 @@ public class NamedAttributeContextManager<T extends NamedAttribute> {
     private Set<NamedAttributeContext<T>> set = Collections
             .newSetFromMap(new ConcurrentHashMap<NamedAttributeContext<T>, Boolean>());
 
-    public void addContext(T attr, Test test) {
+    public synchronized void addContext(T attr, Test test) {
         Optional<NamedAttributeContext<T>> opt = set.stream()
                 .filter(x -> x.getAttr().getName().equals(attr.getName()))
                 .findAny();

src/test/java/com/aventstack/extentreports/model/context/NamedAttributeContextManagerTest.java

@@ -0,0 +1,65 @@
+package com.aventstack.extentreports.model.context;
+
+import java.util.Set;
+import java.util.stream.IntStream;
+
+import org.testng.Assert;
+import org.testng.annotations.BeforeMethod;
+import org.testng.annotations.Test;
+
+import com.aventstack.extentreports.ExtentReports;
+import com.aventstack.extentreports.model.Author;
+import com.aventstack.extentreports.model.Category;
+import com.aventstack.extentreports.model.Device;
+import com.aventstack.extentreports.model.NamedAttribute;
+
+public class NamedAttributeContextManagerTest {
+
+    private final String[] tags = new String[] { "tag1", "tag2", "tag3", "tag4" };
+
+    private ExtentReports _extent;
+
+    @BeforeMethod
+    public void beforeMethod() {
+        _extent = new ExtentReports();
+    }
+
+    /**
+     * This test checks if the context only tracks tag uniqueness across N number of
+     * tests
+     * 
+     * Issue details:
+     * https://github.com/extent-framework/extentreports-java/issues/282
+     */
+    @Test
+    public void concurrentlyAssignedTags() {
+        IntStream.range(1, 100).parallel().forEach(x -> {
+            _extent.createTest("Test" + x).assignCategory(tags).pass("");
+        });
+        final Set<NamedAttributeContext<Category>> set = _extent.getReport().getCategoryCtx().getSet();
+        verifyContentAssert(set);
+    }
+
+    private <T extends NamedAttribute> void verifyContentAssert(final Set<NamedAttributeContext<T>> set) {
+        final String[] runtimeTags = set.stream().map(x -> x.getAttr().getName()).toArray(String[]::new);
+        Assert.assertEqualsNoOrder(tags, runtimeTags);
+    }
+
+    @Test
+    public void concurrentlyAssignedUsers() {
+        IntStream.range(1, 100).parallel().forEach(x -> {
+            _extent.createTest("Test" + x).assignAuthor(tags).pass("");
+        });
+        final Set<NamedAttributeContext<Author>> set = _extent.getReport().getAuthorCtx().getSet();
+        verifyContentAssert(set);
+    }
+
+    @Test
+    public void concurrentlyAssignedDevices() {
+        IntStream.range(1, 100).parallel().forEach(x -> {
+            _extent.createTest("Test" + x).assignDevice(tags).pass("");
+        });
+        final Set<NamedAttributeContext<Device>> set = _extent.getReport().getDeviceCtx().getSet();
+        verifyContentAssert(set);
+    }
+}