Add array spread support (#385)

package.json

@@ -44,7 +44,6 @@
     "@babel/parser": "^7.8.4",
     "@babel/plugin-transform-modules-commonjs": "^7.8.3",
     "@babel/plugin-transform-parameters": "^7.8.4",
-    "@babel/plugin-transform-spread": "^7.8.3",
     "babel-check-duplicated-nodes": "^1.0.0",
     "browserify": "^16.5.0",
     "mocha": "^7.0.1",

packages/regenerator-transform/src/emit.js

@@ -1094,7 +1094,13 @@ Ep.explodeExpression = function(path, ignoreResult) {
   case "ArrayExpression":
     return finish(t.arrayExpression(
       path.get("elements").map(function(elemPath) {
-        return explodeViaTempVar(null, elemPath);
+        if (elemPath.isSpreadElement()) {
+          return t.spreadElement(
+            explodeViaTempVar(null, elemPath.get("argument"))
+          );
+        } else {
+          return explodeViaTempVar(null, elemPath);
+        }
       })
     ));
 

test/run.js

@@ -165,11 +165,10 @@ enqueue(convert, [
   "./test/class.es5.js"
 ]);
 
-function convertWithSpread(es6File, es5File, callback) {
+function convertWithParamsTransform(es6File, es5File, callback) {
   var transformOptions = {
     presets:[require("regenerator-preset")],
     plugins: [
-      require("@babel/plugin-transform-spread"),
       require("@babel/plugin-transform-parameters")
     ],
     parserOpts: {
@@ -200,7 +199,7 @@ function convertWithSpread(es6File, es5File, callback) {
   });
 }
 
-enqueue(convertWithSpread, [
+enqueue(convertWithParamsTransform, [
   "./test/regression.js",
   "./test/regression.es5.js"
 ]);

test/tests.es6.js

@@ -2815,4 +2815,22 @@ describe("expressions containing yield subexpressions", function() {
       done: true
     });
   });
+
+  it("should work when yield is in an array spread", function() {
+    function *gen() {
+      return [0, ...(yield "foo"), 3];
+    }
+
+    var g = gen();
+
+    assert.deepEqual(g.next(), {
+      value: "foo",
+      done: false,
+    });
+
+    assert.deepEqual(g.next([1, 2]), {
+      value: [0, 1, 2, 3],
+      done: true,
+    });
+  });
 });