Remove duplicate messages when combining results

2 files changed, 32 insertions, 1 deletions

diff --git a/lib/results.js b/lib/results.js
index 55efd25..fe9f632 100644
--- a/lib/results.js
+++ b/lib/results.js
@@ -35,5 +35,19 @@ function warning(message) {
 }
 
 function combineMessages(results) {
-    return _.flatten(_.pluck(results, "messages"), true);
+    var messages = [];
+    _.flatten(_.pluck(results, "messages"), true).forEach(function(message) {
+        if (!containsMessage(messages, message)) {
+            messages.push(message);
+        }
+    });
+    return messages;
+}
+
+function containsMessage(messages, message) {
+    return _.find(messages, isSameMessage.bind(null, message)) !== undefined;
+}
+
+function isSameMessage(first, second) {
+    return first.type === second.type && first.message === second.message;
 }
diff --git a/tests/results.tests.js b/tests/results.tests.js
new file mode 100644
index 0000000..3c0df78
--- /dev/null
+++ b/tests/results.tests.js
@@ -0,0 +1,17 @@
+var assert = require("assert");
+
+var results = require("../lib/results");
+var Result = results.Result;
+var test = require("./testing").test;
+
+
+describe("Result.combine", function() {
+    test("removes any duplicate messages", function() {
+        var first = new Result(null, [results.warning("Warning...")]);
+        var second = new Result(null, [results.warning("Warning...")]);
+        
+        var combined = Result.combine([first, second]);
+        
+        assert.deepEqual(combined.messages, [results.warning("Warning...")]);
+    });
+});