javascript - Hur riktar jag in mig på ES2018 i TypeScript?

Jag siktar på ES2018 och bryr mig inte om ES3 eller ES5. Från min tsconfig.json: "target": "ES2018". tsc klagar:

En asynkron funktion eller metod i ES5/ES3 kräver konstruktorn 'Promise'. Se till att du har en deklaration för konstruktorn 'Promise' eller inkludera 'ES2015' i ditt --lib-alternativ.

Jag vet att jag skulle kunna lägga till "lib": ["es2015"] för att lägga till bibliotek till kompileringen men jag behöver inte de biblioteken, jag siktar på ES2018.

Hur riktar jag in mig på ES2018 i TypeScript?

Här är min tsconfig.json:

{
    "compilerOptions": {
            /* Basic Options */
            "target": "ES2018" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */,
            "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
            "lib": ["es2015"] /* 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. */
            // "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. */
    }
}

Svar #1

Lägg bara till ES2018 till lib i tsconfig.json:

"lib": [
  "ES2018"
]

lib är annorlunda än target. target betyder ungefär JavaScript-versionen av de genererade utdatafilerna. lib betyder de funktioner du kommer att använda i TypeScript. Till exempel, du kan använda nya funktioner i ES2018 ("lib": ["ES2018"]), men fortfarande rikta in dig på ES6 ("target": "ES6"). De nya funktionerna kommer att översättas till ES6 under kompileringen (detta kan göras via tredjepartsverktyg som babel, och vissa nya funktioner kanske inte går att översätta, men detta är bara implementeringsdetaljer).

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