插入节点

变量后面插入一个未被初始化的变量

示例代码

var a = 996;

新构造一个 Identifier 类型的节点，然后直接插入

遍历 VariableDeclarator 节点

const vistor = {
    VariableDeclarator(path){
        path.insertAfter(t.Identifier('b'));
    }
}

查看输出结果

使用ExpressionStatement表达式语句

遍历 VariableDeclaration 节点

// var a = 996;b = 250;
const vistor = {
    VariableDeclaration(path){
        const operator = "=";
        const left = t.Identifier('var b');
        const right = t.NumericLiteral(250);

        const new_assign = t.AssignmentExpression(operator, left, right);
        const new_express = t.ExpressionStatement(new_assign);

        path.insertAfter(new_express);
    }
}

查看结果

使用VariableDeclaration表达式语句

遍历 VariableDeclaration 节点

// var a = 996;var b = 250;
const vistor = {
    VariableDeclaration(path){
        const id = t.Identifier('b');
        const init = t.NumericLiteral(250);

        const new_variable = t.VariableDeclarator(id, init)

        const kind = 'var';
        const new_variable_express = t.VariableDeclaration(kind, Array(new_variable))
        path.insertAfter(new_variable_express);
        path.stop();
    }
}

查看结果