Unchecked runtime.lastError when using Chrome API

Question

I use chrome.fileSystem API in my app to open a file. When I click the Cancel button of the file chooser dialog, an error occurs:

Answer 1

For this type of errors try catch won't be helpful. Instead you can access the global variable chrome.runtime.lastError as @xan mentioned in his awesome response above(by the way you should read it and upvote it!).

Now, here I provide an example that can be used:

function catchLastError(){
  if(chrome.runtime.lastError){
    console.log("error: ", chrome.runtime.lastError);
  }else{
    // some code goes here.
  }
}

chrome.fileSystem.chooseEntry(yourEntry,catchLastError);