add support for spreads anywhere in list - fixes #73

lib/6to5/transformers/spread.js

@@ -14,42 +14,68 @@ var getSpreadLiteral = function (spread, file) {
 };
 
 var hasSpread = function (nodes) {
-  return nodes.length && _.last(nodes).type === "SpreadElement";
+  var has = false;
+  _.each(nodes, function (node) {
+    if (node.type === "SpreadElement") {
+      has = true;
+      return false;
+    }
+  });
+  return has;
+};
+
+var build = function (props, file) {
+  var nodes = [];
+
+  var _props = [];
+
+  var push = function () {
+    if (!_props.length) return;
+    nodes.push(b.arrayExpression(_props));
+    _props = [];
+  };
+
+  _.each(props, function (prop) {
+    if (prop.type === "SpreadElement") {
+      push();
+      nodes.push(getSpreadLiteral(prop, file));
+    } else {
+      _props.push(prop);
+    }
+  });
+
+  push();
+
+  return nodes;
 };
 
 exports.ArrayExpression = function (node, parent, file) {
   var elements = node.elements;
   if (!hasSpread(elements)) return;
 
-  var spread = elements.pop();
+  var nodes = build(elements, file);
+  var first = nodes.shift();
 
-  var concat = util.template("array-concat", {
-    ARGUMENT: getSpreadLiteral(spread, file)
-  });
+  if (!nodes.length) return first;
 
-  concat.callee.object.elements = elements;
-
-  return concat;
+  return b.callExpression(b.memberExpression(first, b.identifier("concat"), false), nodes);
 };
 
 exports.CallExpression = function (node, parent, file) {
   var args = node.arguments;
   if (!hasSpread(args)) return;
 
-  var spread = args.pop();
-
-  var spreadLiteral  = getSpreadLiteral(spread, file);
   var contextLiteral = b.literal(null);
 
   node.arguments = [];
 
-  if (args.length) {
-    var concat = util.template("array-concat");
-    concat.arguments = [spreadLiteral];
-    concat.callee.object.elements = args;
-    node.arguments.push(concat);
+  var nodes = build(args, file);
+  var first = nodes.shift();
+
+  if (nodes.length) {
+    node.arguments.push(b.callExpression(b.memberExpression(first, b.identifier("concat"), false), nodes));
   } else {
-    node.arguments.push(spreadLiteral);
+    node.arguments.push(first);
   }
 
   var callee = node.callee;

test/fixtures/syntax/spread/array-literal-first/actual.js

@@ -0,0 +1 @@
+var lyrics = [...parts, "head", "and", "toes"];

test/fixtures/syntax/spread/array-literal-first/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+var _slice = Array.prototype.slice;
+var lyrics = _slice.call(parts).concat(["head", "and", "toes"]);

test/fixtures/syntax/spread/array-literal-middle/actual.js

@@ -0,0 +1 @@
+var a = [b, ...c, d];

test/fixtures/syntax/spread/array-literal-middle/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+var _slice = Array.prototype.slice;
+var a = [b].concat(_slice.call(c), [d]);

test/fixtures/syntax/spread/array-literal-multiple/actual.js

@@ -0,0 +1 @@
+var a = [b, ...c, d, e, ...f];

test/fixtures/syntax/spread/array-literal-multiple/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+var _slice = Array.prototype.slice;
+var a = [b].concat(_slice.call(c), [d, e], _slice.call(f));

test/fixtures/syntax/spread/method-call-first/actual.js

@@ -0,0 +1 @@
+add(...numbers, foo, bar);

test/fixtures/syntax/spread/method-call-first/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+var _slice = Array.prototype.slice;
+add.apply(null, _slice.call(numbers).concat([foo, bar]));

test/fixtures/syntax/spread/method-call-middle/actual.js

@@ -0,0 +1 @@
+add(foo, ...numbers, bar);

test/fixtures/syntax/spread/method-call-middle/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+var _slice = Array.prototype.slice;
+add.apply(null, [foo].concat(_slice.call(numbers), [bar]));

test/fixtures/syntax/spread/method-call-multiple/actual.js

@@ -0,0 +1 @@
+add(foo, ...numbers, bar, what, ...test);

test/fixtures/syntax/spread/method-call-multiple/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+var _slice = Array.prototype.slice;
+add.apply(null, [foo].concat(_slice.call(numbers), [bar, what], _slice.call(test)));