title: How do I target ES2018 in TypeScript?
body: <p>I am targeting ES2018 and do not care about ES3 or ES5. From my tsconfig.json: <code>"target": "ES2018"</code>. <code>tsc</code> complains:</p>
  
  <blockquote>
    <p>An async function or method in ES5/ES3 requires the 'Promise' constructor.  Make
    sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your <code>--lib</code> option.</p>
  </blockquote>
  
  <p>I know I could add <code>"lib": ["es2015"]</code> to add libraries to the compilation but <strong>I don't need those libraries, I am targeting ES2018</strong>.</p>
  
  <p><strong>How do I target ES2018 in TypeScript?</strong></p>
  
  <p>Here is my <code>tsconfig.json</code>:</p>
  
  <pre><code>{
      "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. */
      }
  }
  </code></pre>