使用解析器从javascript中提取私有函数

我试图使用解析器（通过uglify js，但任何其他的都可以）从输入字符串中提取私有函数

a.js的内容

var UglifyJS = require('uglify-js');
var ast = UglifyJS.parse(require('fs').readFileSync('b.js').toString());

var stream = UglifyJS.OutputStream({});

// need to manipulate ast here to extract the `sum` function
ast.print(stream)
console.log(stream+'')

var addRandom = (function() {
    function sum(x, y) {
        return x + y
    };

    return function (input) {
        return sum(input, Math.random());
    };
})();

var UglifyJS = require('uglify-js'),
    fs = require('fs');

function showPrivates(file) {

    var privates = {};

    UglifyJS.parse(fs.readFileSync(file).toString('UTF-8')).walk(new UglifyJS.TreeWalker(function(node) {
        if (node instanceof UglifyJS.AST_Defun) {
            var stream = UglifyJS.OutputStream({});
            node.print(stream);
            privates[node.name.name] = stream.toString('UTF-8');
        }
    }));

    return privates;

}

console.log(showPrivates('b.js').sum);

var addRandom = (function() {

    function sum(x, y) {
        return x + y;
    };

    function random(x) {
        return Math.floor(Math.random()*x);
    };

    return function (input) {
        return sum(input, random(10));
    };
})();

b.js的内容

var UglifyJS = require('uglify-js');
var ast = UglifyJS.parse(require('fs').readFileSync('b.js').toString());

var stream = UglifyJS.OutputStream({});

// need to manipulate ast here to extract the `sum` function
ast.print(stream)
console.log(stream+'')

var addRandom = (function() {
    function sum(x, y) {
        return x + y
    };

    return function (input) {
        return sum(input, Math.random());
    };
})();

var UglifyJS = require('uglify-js'),
    fs = require('fs');

function showPrivates(file) {

    var privates = {};

    UglifyJS.parse(fs.readFileSync(file).toString('UTF-8')).walk(new UglifyJS.TreeWalker(function(node) {
        if (node instanceof UglifyJS.AST_Defun) {
            var stream = UglifyJS.OutputStream({});
            node.print(stream);
            privates[node.name.name] = stream.toString('UTF-8');
        }
    }));

    return privates;

}

console.log(showPrivates('b.js').sum);

var addRandom = (function() {

    function sum(x, y) {
        return x + y;
    };

    function random(x) {
        return Math.floor(Math.random()*x);
    };

    return function (input) {
        return sum(input, random(10));
    };
})();

运行
节点a.js
会产生

var fn=function(){function sum(x,y){return x+y}function addRandom(input){return sum(input,Math.random())}return{addRandom:addRandom}}();

。。。但是我需要在输出之前操作ast，以提取
sum
函数。我想打印出来的是

function sum(x,y){return x+y}

如何在输出之前提取所需的AST树部分？
结果表明，使用TreeWalker是可以管理的

a.js的内容

var UglifyJS = require('uglify-js');
var ast = UglifyJS.parse(require('fs').readFileSync('b.js').toString());

var stream = UglifyJS.OutputStream({});

// need to manipulate ast here to extract the `sum` function
ast.print(stream)
console.log(stream+'')

var addRandom = (function() {
    function sum(x, y) {
        return x + y
    };

    return function (input) {
        return sum(input, Math.random());
    };
})();

var UglifyJS = require('uglify-js'),
    fs = require('fs');

function showPrivates(file) {

    var privates = {};

    UglifyJS.parse(fs.readFileSync(file).toString('UTF-8')).walk(new UglifyJS.TreeWalker(function(node) {
        if (node instanceof UglifyJS.AST_Defun) {
            var stream = UglifyJS.OutputStream({});
            node.print(stream);
            privates[node.name.name] = stream.toString('UTF-8');
        }
    }));

    return privates;

}

console.log(showPrivates('b.js').sum);

var addRandom = (function() {

    function sum(x, y) {
        return x + y;
    };

    function random(x) {
        return Math.floor(Math.random()*x);
    };

    return function (input) {
        return sum(input, random(10));
    };
})();

b.js的内容

var UglifyJS = require('uglify-js');
var ast = UglifyJS.parse(require('fs').readFileSync('b.js').toString());

var stream = UglifyJS.OutputStream({});

// need to manipulate ast here to extract the `sum` function
ast.print(stream)
console.log(stream+'')

var addRandom = (function() {
    function sum(x, y) {
        return x + y
    };

    return function (input) {
        return sum(input, Math.random());
    };
})();

var UglifyJS = require('uglify-js'),
    fs = require('fs');

function showPrivates(file) {

    var privates = {};

    UglifyJS.parse(fs.readFileSync(file).toString('UTF-8')).walk(new UglifyJS.TreeWalker(function(node) {
        if (node instanceof UglifyJS.AST_Defun) {
            var stream = UglifyJS.OutputStream({});
            node.print(stream);
            privates[node.name.name] = stream.toString('UTF-8');
        }
    }));

    return privates;

}

console.log(showPrivates('b.js').sum);

var addRandom = (function() {

    function sum(x, y) {
        return x + y;
    };

    function random(x) {
        return Math.floor(Math.random()*x);
    };

    return function (input) {
        return sum(input, random(10));
    };
})();

。。。看看

console.log(showPrivates('b.js').sum);
// function sum(x,y){return x+y}

你想提取sum来在你的脚本中使用它吗？我想从源代码中提取私有函数作为字符串值来处理。保留原始格式对我来说并不重要。我希望能够提取私有实用程序函数，并通过将它们写入中间文件进行测试。在这个问题中，我特别想知道如何根据私有函数的名称从ast树中提取任意私有函数。@仇恨者请不要在否决投票时停下来，请随意在评论中表达您的蔑视，这样我们就可以了解您需要遍历ast的错误，但是，除了以下内容之外，我找不到任何关于节点对象的有用文档：@MinusFour，这是我已经看到的页面：）也许我需要使用一个不同的解析器/格式化程序来定制输出。我自己也得出了同样的结论。这是一个很好的简洁版本，与我在自己的答案中所说的差不多。
控制台.log
应该在
顶级.walk
调用之后，否则当有多个私有函数时，它将继续输出旧函数和新函数。