vue hello world项目
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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = void 0;
var _helperPluginUtils = require("@babel/helper-plugin-utils");
var _pluginSyntaxNullishCoalescingOperator = require("@babel/plugin-syntax-nullish-coalescing-operator");
var _core = require("@babel/core");
var _default = (0, _helperPluginUtils.declare)((api, {
loose = false
}) => {
var _api$assumption;
api.assertVersion(7);
const noDocumentAll = (_api$assumption = api.assumption("noDocumentAll")) != null ? _api$assumption : loose;
return {
name: "proposal-nullish-coalescing-operator",
inherits: _pluginSyntaxNullishCoalescingOperator.default,
visitor: {
LogicalExpression(path) {
const {
node,
scope
} = path;
if (node.operator !== "??") {
return;
}
let ref;
let assignment;
if (scope.isStatic(node.left)) {
ref = node.left;
assignment = _core.types.cloneNode(node.left);
} else if (scope.path.isPattern()) {
path.replaceWith(_core.template.ast`(() => ${path.node})()`);
return;
} else {
ref = scope.generateUidIdentifierBasedOnNode(node.left);
scope.push({
id: _core.types.cloneNode(ref)
});
assignment = _core.types.assignmentExpression("=", ref, node.left);
}
path.replaceWith(_core.types.conditionalExpression(noDocumentAll ? _core.types.binaryExpression("!=", assignment, _core.types.nullLiteral()) : _core.types.logicalExpression("&&", _core.types.binaryExpression("!==", assignment, _core.types.nullLiteral()), _core.types.binaryExpression("!==", _core.types.cloneNode(ref), scope.buildUndefinedNode())), _core.types.cloneNode(ref), node.right));
}
}
};
});
exports.default = _default;