fixing If/else-to-ternary with instanceof as an unparenthesized condition. JS operator precedence.

lib/grammar.js

@@ -315,7 +315,7 @@
     ],
     SimpleArgs: [
       o("Expression"), o("SimpleArgs , Expression", function() {
-        return $1 instanceof Array ? $1.concat([$3]) : [$1].concat([$3]);
+        return ($1 instanceof Array) ? $1.concat([$3]) : [$1].concat([$3]);
       })
     ],
     Try: [

lib/helpers.js

@@ -80,7 +80,7 @@
     _b = array;
     for (_a = 0, _c = _b.length; _a < _c; _a++) {
       item = _b[_a];
-      item instanceof Array ? (memo = memo.concat(item)) : memo.push(item);
+      (item instanceof Array) ? (memo = memo.concat(item)) : memo.push(item);
     }
     return memo;
   });

lib/nodes.js

@@ -466,7 +466,7 @@
       _c = this.args;
       for (_b = 0, _d = _c.length; _b < _d; _b++) {
         arg = _c[_b];
-        arg instanceof SplatNode ? (compilation = this.compileSplat(o)) : null;
+        (arg instanceof SplatNode) ? (compilation = this.compileSplat(o)) : null;
       }
       if (!(compilation)) {
         args = (function() {
@@ -689,7 +689,7 @@
             if (i === this.properties.length - 1) {
               join = '';
             }
-            indent = prop instanceof CommentNode ? '' : this.idt(1);
+            indent = (prop instanceof CommentNode) ? '' : this.idt(1);
             if (!(prop instanceof AssignNode || prop instanceof CommentNode)) {
               prop = new AssignNode(prop, prop, 'object');
             }
@@ -1371,7 +1371,7 @@
       if (code.substr(l - 1, 1) === ';') {
         code = code.substr(o, l - 1);
       }
-      return this.expression instanceof AssignNode ? code : ("(" + code + ")");
+      return (this.expression instanceof AssignNode) ? code : ("(" + code + ")");
     };
     return ParentheticalNode;
   })();
@@ -1514,11 +1514,13 @@
     IfNode = function(condition, body, tags) {
       this.condition = condition;
       this.body = body;
-      this.elseBody = null;
       this.tags = tags || {};
       if (this.tags.invert) {
         this.condition = new OpNode('!', new ParentheticalNode(this.condition));
+      } else if (this.condition instanceof OpNode && this.condition.operator === 'instanceof') {
+        this.condition = new ParentheticalNode(this.condition);
       }
+      this.elseBody = null;
       this.isChain = false;
       return this;
     };
@@ -1602,7 +1604,7 @@
       }
     };
     IfNode.prototype.ensureExpressions = function(node) {
-      return node instanceof Expressions ? node : new Expressions([node]);
+      return (node instanceof Expressions) ? node : new Expressions([node]);
     };
     IfNode.prototype.compileStatement = function(o) {
       var body, child, comDent, condO, elsePart, ifDent, ifPart;

src/nodes.coffee

@@ -1330,9 +1330,12 @@ exports.IfNode: class IfNode extends BaseNode
   constructor: (condition, body, tags) ->
     @condition: condition
     @body:      body
-    @elseBody:  null
     @tags:      tags or {}
-    @condition: new OpNode('!', new ParentheticalNode(@condition)) if @tags.invert
+    if @tags.invert
+      @condition: new OpNode('!', new ParentheticalNode(@condition))
+    else if @condition instanceof OpNode and @condition.operator is 'instanceof'
+      @condition: new ParentheticalNode(@condition)
+    @elseBody:  null
     @isChain:   false
 
   bodyNode: -> @body?.unwrap()

test/test_if.coffee

@@ -67,3 +67,10 @@ func: ->
   return (if false then callback())
 
 ok func() is null
+
+
+# If-to-ternary with instanceof requires parentheses (no comment).
+if {} instanceof Object
+  ok yes
+else
+  ok no