动态异步函数调用给出了javascript运行时错误

Question

我在for循环中使用它来分配变量，以便具有灵活的可配置解决方案。

以下代码：

   defineRestApi (api, methodName, options = {}) {

        for (const type of Object.keys (api)) {
            for (const httpMethod of Object.keys (api[type])) {

                let paths = api[type][httpMethod]
                for (let i = 0; i < paths.length; i++) {
                    let path = paths[i].trim ()
                    let splitPath = path.split (/[^a-zA-Z0-9]/)

                    let uppercaseMethod  = httpMethod.toUpperCase ()
                    let lowercaseMethod  = httpMethod.toLowerCase ()
                    let camelcaseMethod  = this.capitalize (lowercaseMethod)
                    let camelcaseSuffix  = splitPath.map (this.capitalize).join ('')
                    let underscoreSuffix = splitPath.map (x => x.trim ().toLowerCase ()).filter (x => x.length > 0).join ('_')

                    let camelcase  = type + camelcaseMethod + this.capitalize (camelcaseSuffix)
                    let underscore = type + '_' + lowercaseMethod + '_' + underscoreSuffix

                    if ('suffixes' in options) {
                        if ('camelcase' in options['suffixes'])
                            camelcase += options['suffixes']['camelcase']
                        if ('underscore' in options.suffixes)
                            underscore += options['suffixes']['underscore']
                    }

                    if ('underscore_suffix' in options)
                        underscore += options.underscoreSuffix;
                    if ('camelcase_suffix' in options)
                        camelcase += options.camelcaseSuffix;

                    let partial = async params => this[methodName] (path, type, uppercaseMethod, params || {})

                    this[camelcase]  = partial
                    this[underscore] = partial
                }
            }
        }
    }

  

Typescript 2.7.2，NativeScript

let partial = async params => this[methodName] (path, type, uppercaseMethod, params || {})

给出错误

JS ERROR SyntaxError：意外的标识符＆＃39; params＆＃39;。期待＆＃39 ;;＆＃39;在变量声明之后。

tsc --version 2.7.2

tsconfig：

{
    "compilerOptions": {
        "module": "commonjs",
        "target": "es6",
        "experimentalDecorators": true,
        "emitDecoratorMetadata": true,
        "noEmitHelpers": true,
        "noEmitOnError": true,
        "lib": [
            "es7",
            "es6",
            "dom",
            "es2015.iterable"
        ],
        "baseUrl": ".",
        "paths": {
            "*": [
                "./node_modules/tns-core-modules/*",
                "./node_modules/*"
            ]
        }
    },
    "exclude": [
        "node_modules",
        "platforms",
        "**/*.aot.ts"
    ]
}

看起来像async的函数表达式在某种程度上是错误的。