index.js
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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = void 0;
var _helperPluginUtils = require("@babel/helper-plugin-utils");
var _pluginSyntaxOptionalChaining = _interopRequireDefault(require("@babel/plugin-syntax-optional-chaining"));
var _core = require("@babel/core");
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var _default = (0, _helperPluginUtils.declare)((api, options) => {
api.assertVersion(7);
const {
loose = false
} = options;
return {
name: "proposal-optional-chaining",
inherits: _pluginSyntaxOptionalChaining.default,
visitor: {
"OptionalCallExpression|OptionalMemberExpression"(path) {
const {
parentPath,
scope
} = path;
let isDeleteOperation = false;
const optionals = [];
let optionalPath = path;
while (optionalPath.isOptionalMemberExpression() || optionalPath.isOptionalCallExpression()) {
const {
node
} = optionalPath;
if (node.optional) {
optionals.push(node);
}
if (optionalPath.isOptionalMemberExpression()) {
optionalPath.node.type = "MemberExpression";
optionalPath = optionalPath.get("object");
} else if (optionalPath.isOptionalCallExpression()) {
optionalPath.node.type = "CallExpression";
optionalPath = optionalPath.get("callee");
}
}
let replacementPath = path;
if (parentPath.isUnaryExpression({
operator: "delete"
})) {
replacementPath = parentPath;
isDeleteOperation = true;
}
for (let i = optionals.length - 1; i >= 0; i--) {
const node = optionals[i];
const isCall = _core.types.isCallExpression(node);
const replaceKey = isCall ? "callee" : "object";
const chain = node[replaceKey];
let ref;
let check;
if (loose && isCall) {
check = ref = chain;
} else {
ref = scope.maybeGenerateMemoised(chain);
if (ref) {
check = _core.types.assignmentExpression("=", _core.types.cloneNode(ref), chain);
node[replaceKey] = ref;
} else {
check = ref = chain;
}
}
if (isCall && _core.types.isMemberExpression(chain)) {
if (loose) {
node.callee = chain;
} else {
const {
object
} = chain;
let context = scope.maybeGenerateMemoised(object);
if (context) {
chain.object = _core.types.assignmentExpression("=", context, object);
} else if (_core.types.isSuper(object)) {
context = _core.types.thisExpression();
} else {
context = object;
}
node.arguments.unshift(_core.types.cloneNode(context));
node.callee = _core.types.memberExpression(node.callee, _core.types.identifier("call"));
}
}
replacementPath.replaceWith(_core.types.conditionalExpression(loose ? _core.types.binaryExpression("==", _core.types.cloneNode(check), _core.types.nullLiteral()) : _core.types.logicalExpression("||", _core.types.binaryExpression("===", _core.types.cloneNode(check), _core.types.nullLiteral()), _core.types.binaryExpression("===", _core.types.cloneNode(ref), scope.buildUndefinedNode())), isDeleteOperation ? _core.types.booleanLiteral(true) : scope.buildUndefinedNode(), replacementPath.node));
replacementPath = replacementPath.get("alternate");
}
}
}
};
});
exports.default = _default;