javascript - Node读取ts模块/读取代码文件

Question

如何从文件中读取类？

.src/my-a.service.ts

export class MyAService {
    ...
}

.src/my-b.service.ts

export class MyBService {
    ...
}

./read-modules.js

const fs = require('fs');
const _ = require('lodash');

let files = fs.readdirSync('./src')
    .filter(item => {
        return _.includes(item, '.service.ts')
    });


files.forEach(item => {
    // get ['MyAService', 'MyBService']
});

我知道你可以做一些字符串解析，但是有没有一种高级方法可以从文件中读取 js/ts 导出(不导入代码，而只是获取导出类的名称)。

编辑1:有 X 个 *.service.ts 文件 my-a.service.ts 和 my-b.service.ts 只是示例。我并不是试图导入或要求这些类在代码中使用它们，只是获取用于代码生成的类名称。

编辑2:我看起来 tsreflect-compiler 就是我所需要的:

const fs = require('fs');
const _ = require('lodash');
const compiler = require('tsreflect-compiler');

let files = fs.readdirSync('./src')
    .filter(item => {
        return _.includes(item, '.service.ts')
    });


let mods = new Map();
files.forEach(item => {
    let diag = compiler.compile(
        [`./src/${item}`],
        {
            noLib: false,
            suppressImplicitAnyIndexErrors: true,
            noImplicitAny: false,
            module: 'ES2015',
            moduleResolution: 'Node',
            target: 'ES5'
        },
        {
            readFile: (filename, onError) => {
                let text;
                try {
                    text = fs.readFileSync(filename, 'utf8');
                } catch (error) {
                    if (onError) {
                        onError(e.message);
                    }
                    text = '';
                }
                return text;
            },
            writeFile: (fileName, data, writeByteOrderMark, onError) => {
                mods.set(item, JSON.parse(data).declares.map(d => d.name));
            }
        }
    );
});

mods.forEach((value, key) => {
    console.log(key); // my-a.service.ts
    console.dir(value); // [ 'MyAService' ]
});

但是 tsreflect-compiler 仅使用 TypeScript 1.4 编译器，我需要 2.x 更新版本。有更现代的解决方案吗？

Answer 1

这最终成为我的解决方案:

const fs = require('fs');
const _ = require('lodash');
const ts = require('typescript');

let files = fs.readdirSync('./src')
    .filter(item => _.includes(item, '.service.ts'));

let mods = new Map();
files.forEach(file => {
    let ex = [];
    // https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#using-the-type-checker
    // Build a program using the set of root file names in fileNames
    let program = ts.createProgram(
        [`./src/${file}`],
        {
            module: ts.ModuleKind.ES2015,
            moduleResolution: ts.ModuleResolutionKind.NodeJs,
            target: ts.ScriptTarget.ES5
        }
    );
    // Get the checker, we will use it to find more about classes
    let checker = program.getTypeChecker();
    // Visit every sourceFile in the program
    program.getSourceFiles()
        .filter(sourceFile => _.includes(sourceFile.fileName, file))
        .forEach(sourceFile => {
            // Walk the tree to search for classes
            ts.forEachChild(sourceFile, node => {
                if (node.kind === ts.SyntaxKind.ClassDeclaration) {
                    // This is a top level class, get its symbol
                    let symbol = checker.getSymbolAtLocation(node.name);
                    ex.push(symbol.getName());
                }
            });
        });
    mods.set(file, ex);
});

mods.forEach((value, key) => {
    console.log(key); // my-a.service.ts
    console.dir(value); // [ 'MyAService' ]
});