title: Typescript Error Expected 0 arguments, but got 2 in Ionic Framework
body: <p>The typescript compiler gives me this error</p>
  
  <blockquote>
    <p>typescript: src/pages/login/login.ts, line: 33
                Expected 0 arguments, but got 2.
          L32:  this.auth.loginAPI(this.registerCredentials)
          L33:    .subscribe(response => {</p>
  </blockquote>
  
  <p>With this code (2 files):</p>
  
  <pre><code>// auth-provider.ts
  public loginAPI(credentials: {email:string,password:string}) {
    return this.http.post(this.apiUrl,data);
  }
  
  // login.ts
  this.auth.loginAPI(this.registerCredentials)
    .subscribe(response =&gt; { 
      console.log(response);
    }, err =&gt; {
      console.log(err);
    });
  </code></pre>
  
  <p>The funny thing is that the code works (I edit any file, my ionic serve reloads and the page renders without any problem).</p>
  
  <p>Any idea?</p>
  
  <p>Environment
  cli packages: (/usr/local/lib/node_modules)</p>
  
  <pre><code>@ionic/cli-utils  : 1.19.0
  ionic (Ionic CLI) : 3.19.0
  </code></pre>
  
  <p>global packages:</p>
  
  <pre><code>cordova (Cordova CLI) : 7.0.1
  </code></pre>
  
  <p>local packages:</p>
  
  <pre><code>@ionic/app-scripts : 3.1.5
  Cordova Platforms  : ios 4.4.0
  Ionic Framework    : ionic-angular 3.9.2
  </code></pre>
  
  <p>System:</p>
  
  <pre><code>Node  : v8.9.3
  npm   : 5.5.1
  OS    : macOS High Sierra
  Xcode : Xcode 9.2 Build version 9C40b
  </code></pre>