[ng] ERROR in node_modules/@types/graphql/subscription/subscribe.d.ts(17,12): error TS2583: Cannot find name 'AsyncIterator'. Do you need to change your target library? Try changing the `lib` compiler option to es2015 or later.
[ng] node_modules/@types/graphql/subscription/subscribe.d.ts(29,12): error TS2304: Cannot find name 'AsyncIterable'.

$ ionic serve

> ng run app:serve --host=0.0.0.0 --port=8100
[ng] WARNING: This is a simple server for use in testing or debugging Angular applications
[ng] locally. It hasn't been reviewed for security issues.
[ng] Binding this server to an open connection can result in compromising your application or
[ng] computer. Using a different host than the one passed to the "--host" flag might result in
[ng] websocket connection issues. You might need to use "--disableHostCheck" if that's the
[ng] case.

[INFO] Development server running!

       Local: http://localhost:8100
       External: http://192.168.1.20:8100, http://192.168.33.1:8100

       Use Ctrl+C to quit this process

[INFO] Browser window opened to http://localhost:8100!

[ng] ℹ ｢wdm｣: wait until bundle finished: /
[ng] Date: 2019-02-05T11:16:02.772Z
[ng] Hash: 96588506defafe9d138a
[ng] Time: 7656ms
[ng] chunk {main} main.js, main.js.map (main) 1.87 kB [initial] [rendered]
[ng] chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 92.4 kB [initial] [rendered]
[ng] chunk {runtime} runtime.js, runtime.js.map (runtime) 6.08 kB [entry] [rendered]
[ng] chunk {styles} styles.js, styles.js.map (styles) 79.4 kB [initial] [rendered]
[ng] chunk {vendor} vendor.js, vendor.js.map (vendor) 327 kB [initial] [rendered]
[ng]
[ng] ERROR in node_modules/@types/graphql/subscription/subscribe.d.ts(17,12): error TS2583: Cannot find name 'AsyncIterator'. Do you need to change your target library? Try changing the `lib` compiler option to es2015 or later.
[ng] node_modules/@types/graphql/subscription/subscribe.d.ts(29,12): error TS2304: Cannot find name 'AsyncIterable'.
[ng]
[ng] ℹ ｢wdm｣: Failed to compile.

{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "module": "es2015",
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "target": "es5",
    "typeRoots": [
      "node_modules/@types"
    ],
    "lib": [
      "es2018",
      "esnext.asynciterable", // この行を追加
      "dom"
    ]
  }
}

{
  "name": "PostApp",
  "version": "0.0.1",
  "author": "Ionic Framework",
  "homepage": "https://ionicframework.com/",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/common": "^7.2.2",
    "@angular/core": "^7.2.2",
    "@angular/forms": "^7.2.2",
    "@angular/http": "^7.2.2",
    "@angular/platform-browser": "^7.2.2",
    "@angular/platform-browser-dynamic": "^7.2.2",
    "@angular/router": "^7.2.2",
    "@ionic-native/core": "^5.0.0",
    "@ionic-native/splash-screen": "^5.0.0",
    "@ionic-native/status-bar": "^5.0.0",
    "@ionic/angular": "^4.0.0",
    "aws-appsync": "^1.7.1",
    "core-js": "^2.5.4",
    "graphql-tag": "^2.10.1",
    "rxjs": "~6.3.3",
    "zone.js": "~0.8.29"
  },
  "devDependencies": {
    "@angular-devkit/architect": "~0.12.3",
    "@angular-devkit/build-angular": "~0.12.3",
    "@angular-devkit/core": "~7.2.3",
    "@angular-devkit/schematics": "~7.2.3",
    "@angular/cli": "~7.2.3",
    "@angular/compiler": "~7.2.2",
    "@angular/compiler-cli": "~7.2.2",
    "@angular/language-service": "~7.2.2",
    "@ionic/angular-toolkit": "~1.3.0",
    "@types/node": "~10.12.0",
    "@types/jasmine": "~2.8.8",
    "@types/jasminewd2": "~2.0.3",
    "codelyzer": "~4.5.0",
    "jasmine-core": "~2.99.1",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~3.1.4",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "~2.0.1",
    "karma-jasmine": "~1.1.2",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.4.0",
    "ts-node": "~8.0.0",
    "tslint": "~5.12.0",
    "typescript": "~3.1.6"
  },
  "description": "An Ionic project"
}