clean up conditional assignment operator transformers

lib/6to5/transformation/helpers/build-conditional-assignment-operator-transformer.js

@@ -0,0 +1,75 @@
+var t = require("../../types");
+
+module.exports = function (opts) {
+  var getObjRef = function (node, nodes, file, scope) {
+    var obj = node.object;
+    var temp = scope.generateUidBasedOnNode(obj, file);
+    nodes.push(t.variableDeclaration("var", [
+      t.variableDeclarator(temp, obj)
+    ]));
+    return temp;
+  };
+
+  var getPropRef = function (node, nodes, file, scope) {
+    var prop = node.property;
+    var key = t.toComputedKey(node, prop);
+    if (t.isLiteral(key)) return key;
+
+    var temp = scope.generateUidBasedOnNode(prop, file);
+    nodes.push(t.variableDeclaration("var", [
+      t.variableDeclarator(temp, prop)
+    ]));
+    return temp;
+  };
+
+  var buildAbsoluteRef = function (node, nodes, file, scope) {
+    if (t.isIdentifier(node)) return node;
+
+    var obj = getObjRef(node, nodes, file, scope);
+    var prop = getPropRef(node, nodes, file, scope);
+
+    var computed = node.computed || t.isLiteral(prop);
+    return t.memberExpression(obj, prop, computed);
+  };
+
+  var buildAssignment = function (left, right) {
+    return t.assignmentExpression("=", left, right);
+  };
+
+  var exports = {};
+
+  exports.ExpressionStatement = function (node, parent, scope, context, file) {
+    var expr = node.expression;
+    if (!opts.is(expr)) return;
+
+    var nodes = [];
+    var left  = buildAbsoluteRef(expr.left, nodes, file, scope);
+
+    nodes.push(t.ifStatement(
+      opts.build(left, file),
+      t.expressionStatement(buildAssignment(left, expr.right))
+    ));
+
+    return nodes;
+  };
+
+  exports.AssignmentExpression = function (node, parent, scope, context, file) {
+    if (t.isExpressionStatement(parent)) return;
+    if (!opts.is(node)) return;
+
+    var nodes = [];
+    var left  = buildAbsoluteRef(node.left, nodes, file, scope);
+
+    nodes.push(t.logicalExpression(
+      "&&",
+      opts.build(left, file),
+      buildAssignment(left, node.right)
+    ));
+
+    nodes.push(left);
+
+    return t.toSequenceExpression(nodes, scope);
+  };
+
+  return exports;
+};

lib/6to5/transformation/transformers/playground-mallet-operator.js

@@ -1,86 +1,18 @@
 var t = require("../../types");
 
-var isMallet = function (node) {
-  var is = t.isAssignmentExpression(node) && node.operator === "||=";
-  if (is) {
-    var left = node.left;
-    if (!t.isMemberExpression(left) && !t.isIdentifier(left)) {
-      throw new Error("Expected type MemeberExpression or Identifier");
+module.exports = require("../helpers/build-conditional-assignment-operator-transformer")({
+  is: function (node) {
+    var is = t.isAssignmentExpression(node) && node.operator === "||=";
+    if (is) {
+      var left = node.left;
+      if (!t.isMemberExpression(left) && !t.isIdentifier(left)) {
+        throw new Error("Expected type MemeberExpression or Identifier");
+      }
+      return true;
     }
-    return true;
+  },
+
+  build: function (node) {
+    return t.unaryExpression("!", node, true);
   }
-};
-
-var getObjRef = function (node, nodes, file, scope) {
-  var obj = node.object;
-  if (t.isIdentifier(obj)) return obj;
-
-  var temp = scope.generateUidBasedOnNode(obj, file);
-  nodes.push(t.variableDeclaration("var", [
-    t.variableDeclarator(temp, obj)
-  ]));
-  return temp;
-};
-
-var getPropRef = function (node, nodes, file, scope) {
-  var prop = node.property;
-  var key = t.toComputedKey(node, prop);
-  if (t.isLiteral(key)) return key;
-
-  var temp = scope.generateUidBasedOnNode(prop, file);
-  nodes.push(t.variableDeclaration("var", [
-    t.variableDeclarator(temp, prop)
-  ]));
-  return temp;
-};
-
-var buildAbsoluteRef = function (node, nodes, file, scope) {
-  if (t.isIdentifier(node)) return node;
-
-  var obj = getObjRef(node, nodes, file, scope);
-  var prop = getPropRef(node, nodes, file, scope);
-
-  var computed = node.computed || t.isLiteral(prop);
-  return t.memberExpression(obj, prop, computed);
-};
-
-var buildIsFalsey = function (node) {
-  return t.unaryExpression("!", node, true);
-};
-
-var buildAssignment = function (left, right) {
-  return t.assignmentExpression("=", left, right);
-};
-
-exports.ExpressionStatement = function (node, parent, file, scope) {
-  var expr = node.expression;
-  if (!isMallet(expr)) return;
-
-  var nodes = [];
-  var left = buildAbsoluteRef(expr.left, nodes, file, scope);
-
-  nodes.push(t.ifStatement(
-    buildIsFalsey(left),
-    t.expressionStatement(buildAssignment(left, expr.right))
-  ));
-
-  return nodes;
-};
-
-exports.AssignmentExpression = function (node, parent, file, scope) {
-  if (t.isExpressionStatement(parent)) return;
-  if (!isMallet(node)) return;
-
-  var nodes = [];
-  var left = buildAbsoluteRef(node.left, nodes, file, scope);
-
-  nodes.push(t.logicalExpression(
-    "&&",
-    buildIsFalsey(left),
-    buildAssignment(left, node.right)
-  ));
-
-  nodes.push(left);
-
-  return t.toSequenceExpression(nodes, scope);
-};
+});

lib/6to5/transformation/transformers/playground-memoization-operator.js

@@ -1,88 +1,20 @@
 var t = require("../../types");
 
-var isMemo = function (node) {
-  var is = t.isAssignmentExpression(node) && node.operator === "?=";
-  if (is) t.assertMemberExpression(node.left);
-  return is;
-};
+module.exports = require("../helpers/build-conditional-assignment-operator-transformer")({
+  is: function (node) {
+    var is = t.isAssignmentExpression(node) && node.operator === "?=";
+    if (is) t.assertMemberExpression(node.left);
+    return is;
+  },
 
-var getPropRef = function (nodes, member, file, scope) {
-  var prop = member.property;
-  var key = t.toComputedKey(member, member.property);
-  if (t.isLiteral(key)) {
-    return key;
-  } else {
-    var temp = scope.generateUidBasedOnNode(prop, file);
-    nodes.push(t.variableDeclaration("var", [
-      t.variableDeclarator(temp, prop)
-    ]));
-    return temp;
+  build: function (node, file) {
+    return t.unaryExpression(
+      "!",
+      t.callExpression(
+        t.memberExpression(file.addHelper("has-own"), t.identifier("call")),
+        [node.object, node.property]
+      ),
+      true
+    );
   }
-};
-
-var getObjRef = function (nodes, obj, file, scope) {
-  var temp = scope.generateUidBasedOnNode(obj, file);
-  nodes.push(t.variableDeclaration("var", [
-    t.variableDeclarator(temp, obj)
-  ]));
-  return temp;
-};
-
-var buildHasOwn = function (obj, prop, file) {
-  return t.unaryExpression(
-    "!",
-    t.callExpression(
-      t.memberExpression(file.addHelper("has-own"), t.identifier("call")),
-      [obj, prop]
-    ),
-    true
-  );
-};
-
-var buildAbsoluteRef = function (left, obj, prop) {
-  var computed = left.computed || t.isLiteral(prop);
-  return t.memberExpression(obj, prop, computed);
-};
-
-var buildAssignment = function (expr, obj, prop) {
-  return t.assignmentExpression("=", buildAbsoluteRef(expr.left, obj, prop), expr.right);
-};
-
-exports.ExpressionStatement = function (node, parent, scope, context, file) {
-  var expr = node.expression;
-  if (!isMemo(expr)) return;
-
-  var nodes = [];
-
-  var left = expr.left;
-  var obj  = getObjRef(nodes, left.object, file, scope);
-  var prop = getPropRef(nodes, left, file, scope);
-
-  nodes.push(t.ifStatement(
-    buildHasOwn(obj, prop, file),
-    t.expressionStatement(buildAssignment(expr, obj, prop))
-  ));
-
-  return nodes;
-};
-
-exports.AssignmentExpression = function (node, parent, scope, context, file) {
-  if (t.isExpressionStatement(parent)) return;
-  if (!isMemo(node)) return;
-
-  var nodes = [];
-
-  var left = node.left;
-  var obj  = getObjRef(nodes, left.object, file, scope);
-  var prop = getPropRef(nodes, left, file, scope);
-
-  nodes.push(t.logicalExpression(
-    "&&",
-    buildHasOwn(obj, prop, file),
-    buildAssignment(node, obj, prop)
-  ));
-
-  nodes.push(buildAbsoluteRef(left, obj, prop));
-
-  return t.toSequenceExpression(nodes, scope);
-};
+});