optimize: skip memoising right for ArrayPattern

babel · Mar 29, 2022 · 4eb651d · 4eb651d
1 parent dc3d28d
commit 4eb651d
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Showing 17 changed files with 66 additions and 63 deletions.
diff --git a/packages/babel-plugin-proposal-destructuring-private/src/util.ts b/packages/babel-plugin-proposal-destructuring-private/src/util.ts
@@ -274,6 +274,17 @@ type Item = {
   restExcludingKeys?: ExcludingKey[] | null;
 };
 
+function rightWillBeReferencedOnce(left: LHS) {
+  switch (left.type) {
+    // Skip memoising the right when left is an identifier or
+    // an array pattern
+    case "Identifier":
+    case "ArrayPattern":
+      return true;
+    default:
+      return false;
+  }
+}
 /**
  * Transform private destructuring. It returns a generator
  * which yields a pair of transformed LHS and RHS, which can form VariableDeclaration or
@@ -342,7 +353,7 @@ export function* transformPrivateKeyDestructuring(
         (index = indexPath.shift()) !== undefined ||
         left.type === "AssignmentPattern"
       ) {
-        if (!scope.isStatic(right) && left.type !== "Identifier") {
+        if (!rightWillBeReferencedOnce(left) && !scope.isStatic(right)) {
           const tempId = scope.generateUidIdentifier("m");
           if (isAssignment) {
             scope.push({ id: cloneNode(tempId) });

diff --git a/...turing-private/test/fixtures/assignment--es2015/array-rest-destructuring-middle/output.js b/...turing-private/test/fixtures/assignment--es2015/array-rest-destructuring-middle/output.js
@@ -8,11 +8,11 @@ var _x = {
 };
 
 (() => {
-  var _m, _p, _p2, _m2;
+  var _p, _p2, _m;
 
-  _m = [{
-    y: 1
-  }, C], [{
+  [{
     y
-  }, _p, ..._p2] = _m, _m2 = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x), x = _m2 === void 0 ? y : _m2, z = _p2;
+  }, _p, ..._p2] = [{
+    y: 1
+  }, C], _m = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x), x = _m === void 0 ? y : _m, z = _p2;
 })();
diff --git a/...proposal-destructuring-private/test/fixtures/assignment--es2015/array-rest-only/output.js b/...proposal-destructuring-private/test/fixtures/assignment--es2015/array-rest-only/output.js
@@ -9,10 +9,10 @@ var _x = {
 };
 
 (() => {
-  var _m, _p, _m2, _m3;
+  var _p, _m, _m2;
 
   var x, z;
-  _m = [C], [..._p] = _m, _m2 = _p[0], _m3 = babelHelpers.classStaticPrivateFieldSpecGet(_m2, C, _x), x = _m3 === void 0 ? 1 : _m3, z = babelHelpers.objectWithoutProperties(_p, _excluded);
+  [..._p] = [C], _m = _p[0], _m2 = babelHelpers.classStaticPrivateFieldSpecGet(_m, C, _x), x = _m2 === void 0 ? 1 : _m2, z = babelHelpers.objectWithoutProperties(_p, _excluded);
   result = {
     x,
     z

diff --git a/...ugin-proposal-destructuring-private/test/fixtures/assignment--es2015/array-rest/output.js b/...ugin-proposal-destructuring-private/test/fixtures/assignment--es2015/array-rest/output.js
@@ -8,7 +8,7 @@ var _x = {
 };
 
 (() => {
-  var _m, _p, _p2, _m2;
+  var _p, _p2, _m;
 
-  _m = [C], [_p, ..._p2] = _m, _m2 = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x), x = _m2 === void 0 ? 1 : _m2, z = _p2;
+  [_p, ..._p2] = [C], _m = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x), x = _m === void 0 ? 1 : _m, z = _p2;
 })();
diff --git a/...oposal-destructuring-private/test/fixtures/assignment--es2015/member-expression/output.js b/...oposal-destructuring-private/test/fixtures/assignment--es2015/member-expression/output.js
@@ -16,8 +16,8 @@ var _z = {
 };
 
 (() => {
-  var _m, _p, _p2;
+  var _p, _p2;
 
   let z;
-  _m = [0, C], [babelHelpers.classStaticPrivateFieldDestructureSet(C, C, _x).value, _p, ..._p2] = _m, x = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x), z = _p2;
+  [babelHelpers.classStaticPrivateFieldDestructureSet(C, C, _x).value, _p, ..._p2] = [0, C], x = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x), z = _p2;
 })();
diff --git a/...structuring-private/test/fixtures/assignment--es2015/nested-under-array-pattern/output.js b/...structuring-private/test/fixtures/assignment--es2015/nested-under-array-pattern/output.js
@@ -19,8 +19,8 @@ var _z = {
 babelHelpers.defineProperty(C, "self", C);
 
 (() => {
-  var _m, _p, _p2, _p3, _m2, _m3, _p4, _m4, _m5;
+  var _p, _p2, _p3, _m, _p4, _m2, _m3;
 
   let x, y, z;
-  _m = [C, C], [_p, _p2,, _p3] = _m, _m2 = _p === void 0 ? C.self : _p, x = babelHelpers.classStaticPrivateFieldSpecGet(_m2, C, _x), _m3 = babelHelpers.classStaticPrivateFieldSpecGet(_p2, C, _y), [, _p4] = _m3, _m4 = _p4 === void 0 ? C.self : _p4, _m5 = babelHelpers.classStaticPrivateFieldSpecGet(_m4, C, _z), y = _m5 === void 0 ? babelHelpers.classStaticPrivateMethodGet(C, C, _self).call(C) : _m5, z = _p3 === void 0 ? babelHelpers.classStaticPrivateFieldSpecGet(y, C, _y) : _p3;
+  [_p, _p2,, _p3] = [C, C], _m = _p === void 0 ? C.self : _p, x = babelHelpers.classStaticPrivateFieldSpecGet(_m, C, _x), [, _p4] = babelHelpers.classStaticPrivateFieldSpecGet(_p2, C, _y), _m2 = _p4 === void 0 ? C.self : _p4, _m3 = babelHelpers.classStaticPrivateFieldSpecGet(_m2, C, _z), y = _m3 === void 0 ? babelHelpers.classStaticPrivateMethodGet(C, C, _self).call(C) : _m3, z = _p3 === void 0 ? babelHelpers.classStaticPrivateFieldSpecGet(y, C, _y) : _p3;
 })();
diff --git a/...-destructuring-private/test/fixtures/assignment/array-rest-destructuring-middle/output.js b/...-destructuring-private/test/fixtures/assignment/array-rest-destructuring-middle/output.js
@@ -3,12 +3,12 @@ let x, y, z;
 class C {
   static #x;
   static {
-    var _m, _p, _p2, _m2;
+    var _p, _p2, _m;
 
-    _m = [{
-      y: 1
-    }, C], [{
+    [{
       y
-    }, _p, ..._p2] = _m, _m2 = _p.#x, x = _m2 === void 0 ? y : _m2, z = _p2;
+    }, _p, ..._p2] = [{
+      y: 1
+    }, C], _m = _p.#x, x = _m === void 0 ? y : _m, z = _p2;
   }
 }
diff --git a/...-plugin-proposal-destructuring-private/test/fixtures/assignment/array-rest-only/output.js b/...-plugin-proposal-destructuring-private/test/fixtures/assignment/array-rest-only/output.js
@@ -4,10 +4,10 @@ let result;
 class C {
   static #x;
   static {
-    var _m, _p, _m2, _m3;
+    var _p, _m, _m2;
 
     var x, z;
-    _m = [C], [..._p] = _m, _m2 = _p[0], _m3 = _m2.#x, x = _m3 === void 0 ? 1 : _m3, z = babelHelpers.objectWithoutProperties(_p, _excluded);
+    [..._p] = [C], _m = _p[0], _m2 = _m.#x, x = _m2 === void 0 ? 1 : _m2, z = babelHelpers.objectWithoutProperties(_p, _excluded);
     result = {
       x,
       z

diff --git a/...babel-plugin-proposal-destructuring-private/test/fixtures/assignment/array-rest/output.js b/...babel-plugin-proposal-destructuring-private/test/fixtures/assignment/array-rest/output.js
@@ -3,8 +3,8 @@ let x, z;
 class C {
   static #x;
   static {
-    var _m, _p, _p2, _m2;
+    var _p, _p2, _m;
 
-    _m = [C], [_p, ..._p2] = _m, _m2 = _p.#x, x = _m2 === void 0 ? 1 : _m2, z = _p2;
+    [_p, ..._p2] = [C], _m = _p.#x, x = _m === void 0 ? 1 : _m, z = _p2;
   }
 }
diff --git a/...lugin-proposal-destructuring-private/test/fixtures/assignment/member-expression/output.js b/...lugin-proposal-destructuring-private/test/fixtures/assignment/member-expression/output.js
@@ -5,9 +5,9 @@ class C {
   static #y;
   static #z;
   static {
-    var _m, _p, _p2;
+    var _p, _p2;
 
     let z;
-    _m = [0, C], [C.#x, _p, ..._p2] = _m, x = _p.#x, z = _p2;
+    [C.#x, _p, ..._p2] = [0, C], x = _p.#x, z = _p2;
   }
 }
diff --git a/...posal-destructuring-private/test/fixtures/assignment/nested-under-array-pattern/output.js b/...posal-destructuring-private/test/fixtures/assignment/nested-under-array-pattern/output.js
@@ -9,9 +9,9 @@ class C {
   }
 
   static {
-    var _m, _p, _p2, _p3, _m2, _m3, _p4, _m4, _m5;
+    var _p, _p2, _p3, _m, _p4, _m2, _m3;
 
     let x, y, z;
-    _m = [this, this], [_p, _p2,, _p3] = _m, _m2 = _p === void 0 ? C.self : _p, x = _m2.#x, _m3 = _p2.#y, [, _p4] = _m3, _m4 = _p4 === void 0 ? C.self : _p4, _m5 = _m4.#z, y = _m5 === void 0 ? C.#self() : _m5, z = _p3 === void 0 ? y.#y : _p3;
+    [_p, _p2,, _p3] = [this, this], _m = _p === void 0 ? C.self : _p, x = _m.#x, [, _p4] = _p2.#y, _m2 = _p4 === void 0 ? C.self : _p4, _m3 = _m2.#z, y = _m3 === void 0 ? C.#self() : _m3, z = _p3 === void 0 ? y.#y : _p3;
   }
 }
diff --git a/...estructuring-private/test/fixtures/variable-declaration--es2015/array-rest-only/output.js b/...estructuring-private/test/fixtures/variable-declaration--es2015/array-rest-only/output.js
@@ -9,11 +9,10 @@ var _x = {
 };
 
 (() => {
-  var _m = [C],
-      [..._p] = _m,
-      _m2 = _p[0],
-      _m3 = babelHelpers.classStaticPrivateFieldSpecGet(_m2, C, _x),
-      x = _m3 === void 0 ? 1 : _m3,
+  var [..._p] = [C],
+      _m = _p[0],
+      _m2 = babelHelpers.classStaticPrivateFieldSpecGet(_m, C, _x),
+      x = _m2 === void 0 ? 1 : _m2,
       z = babelHelpers.objectWithoutProperties(_p, _excluded);
 
   result = {

diff --git a/...sal-destructuring-private/test/fixtures/variable-declaration--es2015/array-rest/output.js b/...sal-destructuring-private/test/fixtures/variable-declaration--es2015/array-rest/output.js
@@ -6,9 +6,8 @@ var _x = {
 };
 
 (() => {
-  var _m = [C],
-      [_p, ..._p2] = _m,
-      _m2 = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x),
-      x = _m2 === void 0 ? 1 : _m2,
+  var [_p, ..._p2] = [C],
+      _m = babelHelpers.classStaticPrivateFieldSpecGet(_p, C, _x),
+      x = _m === void 0 ? 1 : _m,
       z = _p2;
 })();
diff --git a/...g-private/test/fixtures/variable-declaration--es2015/nested-under-array-pattern/output.js b/...g-private/test/fixtures/variable-declaration--es2015/nested-under-array-pattern/output.js
@@ -19,14 +19,12 @@ var _z = {
 babelHelpers.defineProperty(C, "self", C);
 
 (() => {
-  var _m = [C, C],
-      [_p, _p2,, _p3] = _m,
-      _m2 = _p === void 0 ? C.self : _p,
-      x = babelHelpers.classStaticPrivateFieldSpecGet(_m2, C, _x),
-      _m3 = babelHelpers.classStaticPrivateFieldSpecGet(_p2, C, _y),
-      [, _p4] = _m3,
-      _m4 = _p4 === void 0 ? C.self : _p4,
-      _m5 = babelHelpers.classStaticPrivateFieldSpecGet(_m4, C, _z),
-      y = _m5 === void 0 ? babelHelpers.classStaticPrivateMethodGet(C, C, _self).call(C) : _m5,
+  var [_p, _p2,, _p3] = [C, C],
+      _m = _p === void 0 ? C.self : _p,
+      x = babelHelpers.classStaticPrivateFieldSpecGet(_m, C, _x),
+      [, _p4] = babelHelpers.classStaticPrivateFieldSpecGet(_p2, C, _y),
+      _m2 = _p4 === void 0 ? C.self : _p4,
+      _m3 = babelHelpers.classStaticPrivateFieldSpecGet(_m2, C, _z),
+      y = _m3 === void 0 ? babelHelpers.classStaticPrivateMethodGet(C, C, _self).call(C) : _m3,
       z = _p3 === void 0 ? babelHelpers.classStaticPrivateFieldSpecGet(y, C, _y) : _p3;
 })();
diff --git a/...oposal-destructuring-private/test/fixtures/variable-declaration/array-rest-only/output.js b/...oposal-destructuring-private/test/fixtures/variable-declaration/array-rest-only/output.js
@@ -4,11 +4,10 @@ let result;
 class C {
   static #x;
   static {
-    var _m = [C],
-        [..._p] = _m,
-        _m2 = _p[0],
-        _m3 = _m2.#x,
-        x = _m3 === void 0 ? 1 : _m3,
+    var [..._p] = [C],
+        _m = _p[0],
+        _m2 = _m.#x,
+        x = _m2 === void 0 ? 1 : _m2,
         z = babelHelpers.objectWithoutProperties(_p, _excluded);
     result = {
       x,

diff --git a/...in-proposal-destructuring-private/test/fixtures/variable-declaration/array-rest/output.js b/...in-proposal-destructuring-private/test/fixtures/variable-declaration/array-rest/output.js
@@ -1,10 +1,9 @@
 class C {
   static #x;
   static {
-    var _m = [C],
-        [_p, ..._p2] = _m,
-        _m2 = _p.#x,
-        x = _m2 === void 0 ? 1 : _m2,
+    var [_p, ..._p2] = [C],
+        _m = _p.#x,
+        x = _m === void 0 ? 1 : _m,
         z = _p2;
   }
 }
diff --git a/...ructuring-private/test/fixtures/variable-declaration/nested-under-array-pattern/output.js b/...ructuring-private/test/fixtures/variable-declaration/nested-under-array-pattern/output.js
@@ -9,15 +9,13 @@ class C {
   }
 
   static {
-    var _m = [this, this],
-        [_p, _p2,, _p3] = _m,
-        _m2 = _p === void 0 ? C.self : _p,
-        x = _m2.#x,
-        _m3 = _p2.#y,
-        [, _p4] = _m3,
-        _m4 = _p4 === void 0 ? C.self : _p4,
-        _m5 = _m4.#z,
-        y = _m5 === void 0 ? C.#self() : _m5,
+    var [_p, _p2,, _p3] = [this, this],
+        _m = _p === void 0 ? C.self : _p,
+        x = _m.#x,
+        [, _p4] = _p2.#y,
+        _m2 = _p4 === void 0 ? C.self : _p4,
+        _m3 = _m2.#z,
+        y = _m3 === void 0 ? C.#self() : _m3,
         z = _p3 === void 0 ? y.#y : _p3;
 
   }