title: ReactNative native-modules Promise passing field and in Swift
body: <p>I'm trying to run a promise in React Native using Swift and passing one field (array). 
  This is the code that i have:</p>
  
  <p>GuidedTourInterfaceBridge.m</p>
  
  <pre><code>@interface RCT_EXTERN_MODULE(GuidedTourInterface, NSObject)
  
     RCT_EXTERN_METHOD(readFile(_ arr: NSArray, resolver: RCTPromiseResolveBlock resolve, rejecter reject: RCTPromiseRejectBlock reject))
  @end
  </code></pre>
  
  <p>GuidedTourInterface.swift:</p>
  
  <pre><code>...
  @objc
  func readFile(_ arr: NSArray, resolver resolve: RCTPromiseResolveBlock, rejecter reject: RCTPromiseRejectBlock) -&gt; Void {
      ...
      resolve(["success" : true, "base64Content" : base64Content ])
  }
  ...
  </code></pre>
  
  <p>JS File:</p>
  
  <pre><code>...
  readFileInfoJson = async () =&gt; {
    try {
  
        var result = await guidedTourInterface.readFile([this.props.mapToShow+"/info.json"]);
        ...
     } catch (e) {
        console.error(e);
     }
   }
  </code></pre>
  
  <p>The error message I am receiving:</p>
  
  <blockquote>
    <p>guidedTourInterface.readFile is not a function. (In
    'guidedTourInterface.readFile([_this.props.mapToShow+"/info.json"])',
    'guidedTourInterface.readFile' is undefined)]</p>
  </blockquote>
  
  <p>Do you have any suggestions how to solve this or what I am doing wrong?
  Thanks in advance</p>