TS2585：“承诺”仅指一种类型，但在此处用作值

Question

我收到以下错误

node_modules/rxjs/internal/Observable.d.ts:82:59 - 错误 TS2585：'Promise' 仅指一种类型，但在此处用作值。您需要更改目标库吗？尝试将 lib 编译器选项更改为 es2015 或更高版本。

格式化后的样子，

node_modules/rxjs/internal/Observable.d.ts:82:59 - error TS2585: 'Promise' only refers to a type, but is being used as a value here. Do you need to change your target library? Try changing the `lib` compiler option to es2015 or later.                                                                   

82     toPromise<T>(this: Observable<T>, PromiseCtor: typeof Promise): Promise<T>;                                                                    
                                                             ~~~~~~~


Found 1 error.

但我试图运行的代码是来自示例，

import { range } from 'rxjs';
import { map, filter } from 'rxjs/operators';

range(1, 200).pipe(
  filter(x => x % 2 === 1),
  map(x => x + x)
).subscribe(x => console.log(x));

我有我的tsconfig.json

"target": "ES2018",                                                                                       
"module": "es2015",   
"lib": ["es2015"],

我在 Node v11.6.0 下运行 Rx.js 6.3.3、TypeScript 3.2.2。我试过了

npm i --save-dev  @types/es6-promise

几乎所有更改 lib 和 module 的组合

我的 ts 配置就是这样，

{
  "compilerOptions": {
    /* Basic Options */
    "target": "ES2016",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
    "module": "es2015",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
    "lib": ["es2016"],                             /* Specify library files to be included in the compilation. */
    // "allowJs": true,                       /* Allow javascript files to be compiled. */
    // "checkJs": true,                       /* Report errors in .js files. */
    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
    // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
    // "outFile": "./",                       /* Concatenate and emit output to single file. */
    // "outDir": "./",                        /* Redirect output structure to the directory. */
    // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
    // "composite": true,                     /* Enable project compilation */
    // "removeComments": true,                /* Do not emit comments to output. */
    // "noEmit": true,                        /* Do not emit outputs. */
    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */

    /* Strict Type-Checking Options */
    "strict": true,                           /* Enable all strict type-checking options. */
    // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
    // "strictNullChecks": true,              /* Enable strict null checks. */
    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
    // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    // "noUnusedLocals": true,                /* Report errors on unused locals. */
    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */

    /* Module Resolution Options */
    "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
    // "typeRoots": [],                       /* List of folders to include type definitions from. */
    // "types": [],                           /* Type declaration files to be included in compilation. */
    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
    "esModuleInterop": true                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */

    /* Source Map Options */
    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */

    /* Experimental Options */
    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
  }
}

Answer 1

问题

TypeScript 有两种模式。

1. 项目构建器模式（当 tsc 不带参数调用时）
2. 一种编译模式（当tsc 使用任何参数调用时）不会从配置文件tsconfig.json 中读取

如果这听起来令人困惑，那么当您考虑时会更加令人困惑

1. 编译器模式接受配置文件的标志称为--project
2. 在项目构建器的配置文件中，pragma 被称为“compilerOptions”
3. 编译器模式和项目构建器模式接受相同的配置文件

无论如何，这里的问题是 TypeScript 只是忽略了我正在运行它的当前工作目录中的配置文件。

如果您想在此处查看更改后的投票，

• https://twitter.com/TheEvanCarroll/status/1080899909522477061

这里有进一步的报道，

• https://github.com/Microsoft/TypeScript/issues/29241

Answer 2

只需从 npm 安装 @types/node。这应该可以解决问题。

npm install @types/node

Answer 3

就我而言，我只是添加了一个 tsconfig.json 文件，其中包含以下内容，其中与上述错误相关的重要部分是 "target": "es2015"：

{
    "compilerOptions": {
        "noImplicitAny": false,
        "noEmitOnError": true,
        "removeComments": false,
        "sourceMap": true,
        "target": "es2015"
    },
    "include": [
        "file.ts"
    ],
    "exclude": [
        "node_modules",
        "wwwroot"
    ]
}

Answer 4

在编译时使用它。

tsc async_await.ts --lib es2015