Ensure join node handles missing buffer joiner when not in string mode

and add tests
to close #2491

packages/node_modules/@node-red/nodes/core/sequence/17-split.html

@@ -14,7 +14,7 @@
   limitations under the License.
 -->
 
-<script type="text/x-red" data-template-name="split">
+<script type="text/html" data-template-name="split">
     <div class="form-row"><span data-i18n="[html]split.intro"></span></div>
     <div class="form-row"><span data-i18n="[html]split.strBuff"></span></div>
     <div class="form-row">
@@ -113,7 +113,7 @@
 </script>
 
 
-<script type="text/x-red" data-template-name="join">
+<script type="text/html" data-template-name="join">
     <div class="form-row">
         <label data-i18n="join.mode.mode"></label>
         <select id="node-input-mode" style="width:200px;">

packages/node_modules/@node-red/nodes/core/sequence/17-split.js

@@ -292,7 +292,6 @@ module.exports = function(RED) {
                 reduceMessageGroup(node,msgs,exp,fixup,count,result,done);
             }
         });
-
     }
     function reduceAndSendGroup(node, group, done) {
         var is_right = node.reduce_right;
@@ -331,7 +330,7 @@ module.exports = function(RED) {
             var pending_count = node.pending_count;
             var gid = msg.parts.id;
             var count;
-            if(!pending.hasOwnProperty(gid)) {
+            if (!pending.hasOwnProperty(gid)) {
                 if(parts.hasOwnProperty('count')) {
                     count = msg.parts.count;
                 }
@@ -361,7 +360,6 @@ module.exports = function(RED) {
                 }
                 return done();
             }
-
             if (msgs.length === group.count) {
                 delete pending[gid];
                 pending_count -= msgs.length;
@@ -408,7 +406,7 @@ module.exports = function(RED) {
         if (this.joinerType === "str") {
             this.joiner = this.joiner.replace(/\\n/g,"\n").replace(/\\r/g,"\r").replace(/\\t/g,"\t").replace(/\\e/g,"\e").replace(/\\f/g,"\f").replace(/\\0/g,"\0");
         } else if (this.joinerType === "bin") {
-            var joinArray = JSON.parse(n.joiner)
+            var joinArray = JSON.parse(n.joiner || "[]");
             if (Array.isArray(joinArray)) {
                 this.joiner = Buffer.from(joinArray);
             } else {
@@ -448,6 +446,9 @@ module.exports = function(RED) {
                             buffers.push(joinBuffer);
                             bufferLen += joinBuffer.length;
                         }
+                        if (!Buffer.isBuffer(group.payload[i])) { 
+                            group.payload[i] = Buffer.from(group.payload[i]);
+                        }
                         buffers.push(group.payload[i]);
                         bufferLen += group.payload[i].length;
                     }

test/nodes/core/sequence/17-split_spec.js

@@ -517,6 +517,49 @@ describe('JOIN node', function() {
         });
     });
 
+    it('should join things into an array after a count with a buffer join set', function(done) {
+        var flow = [{id:"n1", type:"join", wires:[["n2"]], count:3, joinerType:"bin", joiner:"" ,mode:"custom"},
+                    {id:"n2", type:"helper"}];
+        helper.load(joinNode, flow, function() {
+            var n1 = helper.getNode("n1");
+            var n2 = helper.getNode("n2");
+            n2.on("input", function(msg) {
+                try {
+                    msg.should.have.property("payload");
+                    msg.payload.should.be.an.Array();
+                    msg.payload[0].should.equal(1);
+                    msg.payload[1].should.equal(true);
+                    //msg.payload[2].a.should.equal(1);
+                    done();
+                }
+                catch(e) {done(e);}
+            });
+            n1.receive({payload:1});
+            n1.receive({payload:true});
+            n1.receive({payload:{a:1}});
+        });
+    });
+
+    it('should join strings into a buffer after a count', function(done) {
+        var flow = [{id:"n1", type:"join", wires:[["n2"]], count:2, build:"buffer", joinerType:"bin", joiner:"", mode:"custom"},
+                    {id:"n2", type:"helper"}];
+        helper.load(joinNode, flow, function() {
+            var n1 = helper.getNode("n1");
+            var n2 = helper.getNode("n2");
+            n2.on("input", function(msg) {
+                try {
+                    msg.should.have.property("payload");
+                    msg.payload.length.should.equal(10);
+                    msg.payload.toString().should.equal("helloworld");
+                    done();
+                }
+                catch(e) {done(e);}
+            });
+            n1.receive({payload:"hello"});
+            n1.receive({payload:"world"});
+        });
+    });
+
     it('should join things into an object after a count', function(done) {
         var flow = [{id:"n1", type:"join", wires:[["n2"]], count:5, build:"object", mode:"custom"},
                     {id:"n2", type:"helper"}];