Merge context with set{Extra,Tags}Context instead of clobbering

Fixes #255

Author: mattrobenolt

CHANGELOG.md

@@ -8,6 +8,7 @@
 * DEPRECATED: Replace `Raven.setReleaseContext` with `Raven.setRelease`.
 * NEW: Add `Raven.clearContext()` to empty all of the context.
 * NEW: Add `Raven.getContext()` to get a copy of the current context.
+* NEW: `Raven.set{Extra,Tags}Context(ctx)` now merges with existing values instead of overwriting.
 
 ## 1.1.22
 

src/raven.js

@@ -295,31 +295,40 @@ var Raven = {
      * @return {Raven}
      */
     setUserContext: function(user) {
+        // Intentionally do not merge here since that's an unexpected behavior.
         globalContext.user = user;
 
         return Raven;
     },
 
     /*
-     * Set extra attributes to be sent along with the payload.
+     * Merge extra attributes to be sent along with the payload.
      *
      * @param {object} extra An object representing extra data [optional]
      * @return {Raven}
      */
     setExtraContext: function(extra) {
-        globalContext.extra = extra || {};
+        if (isUndefined(extra)) {
+            delete globalContext.extra;
+        } else {
+            globalContext.extra = objectMerge(globalContext.extra || {}, extra);
+        }
 
         return Raven;
     },
 
     /*
-     * Set tags to be sent along with the payload.
+     * Merge tags to be sent along with the payload.
      *
      * @param {object} tags An object representing tags [optional]
      * @return {Raven}
      */
     setTagsContext: function(tags) {
-        globalContext.tags = tags || {};
+        if (isUndefined(tags)) {
+            delete globalContext.tags;
+        } else {
+            globalContext.tags = objectMerge(globalContext.tags || {}, tags);
+        }
 
         return Raven;
     },

test/raven.test.js

@@ -1843,7 +1843,13 @@ describe('Raven (public API)', function() {
         it('should clear globalContext.extra with no arguments', function() {
             globalOptions.extra = {name: 'Matt'};
             Raven.setExtraContext();
-            assert.deepEqual(globalContext.extra, {});
+            assert.isUndefined(globalContext.extra);
+        });
+
+        it('should merge globalContext.extra with subsequent calls', function() {
+            Raven.setExtraContext({a: 1});
+            Raven.setExtraContext({b: 2});
+            assert.deepEqual(globalContext.extra, {a: 1, b: 2});
         });
     });
 
@@ -1856,7 +1862,13 @@ describe('Raven (public API)', function() {
         it('should clear globalContext.tags with no arguments', function() {
             globalContext.tags = {name: 'Matt'};
             Raven.setTagsContext();
-            assert.deepEqual(globalContext.tags, {});
+            assert.isUndefined(globalContext.tags);
+        });
+
+        it('should merge globalContext.tags with subsequent calls', function() {
+            Raven.setTagsContext({a: 1});
+            Raven.setTagsContext({b: 2});
+            assert.deepEqual(globalContext.tags, {a: 1, b: 2});
         });
     });