title: Angular 7 Property 'size' is missing in type 'Response'
body: <p>So recently I updated my angular application, well I tried to. And this one error popped up and I don't know how to fix it. This error popped up in a function where the application downloads an Excel sheet and tries to open it in another window, this worked before the update. But after I updated to angular 7.1.0 It gave me the following error:</p>
  
  <pre><code>// the function related to this error is shown down below    
  ERROR in src/app/adres.service.ts(87,28): error TS2322: Type 'Response' is not assignable to type 'BlobPart'.
        Type 'Response' is not assignable to type 'Blob'.
          Property 'size' is missing in type 'Response'
  </code></pre>
  
  <p><strong>Imports of adres service</strong></p>
  
  <pre><code>import { Injectable } from '@angular/core';
  import { HttpClient, HttpHeaders } from '@angular/common/http';
  import { HttpModule, ResponseContentType, Jsonp, RequestOptions, Headers } from '@angular/http';
  import { Mail } from './models/mail';
  import { Klant } from './models/klant';
  import { Observable } from 'rxjs/Observable';
  import { GlobalsService } from './globals.service';
  </code></pre>
  
  <p><strong>The function</strong></p>
  
  <pre><code>  private downloadFile(data: Response) {
      const blob = new Blob([data], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });
      const url = window.URL.createObjectURL(blob);
      window.open(url);
    }
  </code></pre>
  
  <p><strong>Package.json</strong></p>
  
  <pre><code> "dependencies": {
      "@angular/animations": "^7.1.1",
      "@angular/cdk": "^7.1.0",
      "@angular/common": "~7.1.0",
      "@angular/compiler": "~7.1.0",
      "@angular/core": "~7.1.0",
      "@angular/forms": "~7.1.0",
      "@angular/http": "^7.1.1",
      "@angular/material": "^7.1.0",
      "@angular/platform-browser": "~7.1.0",
      "@angular/platform-browser-dynamic": "~7.1.0",
      "@angular/router": "~7.1.0",
      "chart.js": "^2.7.3",
      "core-js": "^2.5.4",
      "ng2-ckeditor": "^1.2.2",
      "ng2-datepicker": "^3.1.1",
      "ng2-google-charts": "^3.5.0",
      "rxjs": "^6.3.3",
      "rxjs-compat": "^6.3.3",
      "tslib": "^1.9.0",
      "zone.js": "~0.8.26"
    },
    "devDependencies": {
      "@angular-devkit/build-angular": "~0.11.0",
      "@angular/cli": "~7.1.0",
      "@angular/compiler-cli": "~7.1.0",
      "@angular/language-service": "~7.1.0",
      "@types/node": "~8.9.4",
      "@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": "~3.1.1",
      "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": "~7.0.0",
      "tslint": "~5.11.0",
      "typescript": "~3.1.6"
    }
  </code></pre>
  
  <p>the function I'm currently using worked until the 7.1.0 update. Can anybody tell what happened and how to fix it in this version?</p>