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Order of arguments initialization - fixes T6809

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When using a default param + some destructuring param + a rest param, the
initialization order of the destructured arguments was incorrect due to the
presence of the rest parameter.
This commit is contained in:
Victor Felder
2015-12-21 02:53:36 +01:00
parent bbd14f88c4
commit 28adaa49b2
3 changed files with 24 additions and 3 deletions
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10
packages/babel-plugin-transform-es2015-parameters/src/destructuring.js
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@@ -3,8 +3,12 @@ import * as t from "babel-types";
export let visitor = {
Function(path) {
let params: Array = path.get("params");
for (let i = 0; i < params.length; i++) {
// If there's a rest param, no need to loop through it. Also, we need to
// hoist one more level to get `declar` at the right spot.
const hoistTweak = t.isRestElement(params[params.length - 1]) ? 1 : 0;
for (let i = 0; i < params.length - hoistTweak; i++) {
let param = params[i];
if (param.isArrayPattern() || param.isObjectPattern()) {
let uid = path.scope.generateUidIdentifier("ref");
@@ -12,7 +16,7 @@ export let visitor = {
let declar = t.variableDeclaration("let", [
t.variableDeclarator(param.node, uid)
]);
declar._blockHoist = params.length - i;
declar._blockHoist = params.length - i - hoistTweak;
path.ensureBlock();
path.get("body").unshiftContainer("body", declar);

4
packages/babel-plugin-transform-es2015-parameters/test/fixtures/parameters/destructuring-rest/actual.js vendored Normal file
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@@ -0,0 +1,4 @@
// T6809
function t(x = "default", { a, b }, ...args) {
console.log(x, a, b, args);
}

13
packages/babel-plugin-transform-es2015-parameters/test/fixtures/parameters/destructuring-rest/expected.js vendored Normal file
View File

@@ -0,0 +1,13 @@
// T6809
function t() {
var x = arguments.length <= 0 || arguments[0] === undefined ? "default" : arguments[0];
var _ref = arguments[1];
var a = _ref.a;
var b = _ref.b;
for (var _len = arguments.length, args = Array(_len > 2 ? _len - 2 : 0), _key = 2; _key < _len; _key++) {
args[_key - 2] = arguments[_key];
}
console.log(x, a, b, args);
}