Issue 5220 - Update the IO API

lib/io.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 43 matching lines @@
       },
       resolve
     );
   });
 }
 
 function removeFile(fileName)
 {
   return new Promise((resolve, reject) =>
   {
-    ext.storage.remove(fileToKey(fileName), resolve);
+    ext.storage.remove(fileToKey(fileName), () =>
+    {
+      if (chrome.runtime.lastError)
+        reject(chrome.runtime.lastError.message);
+      else
+        resolve();
+    });
   });
 }
 
 exports.IO =
 {
   /**
    * Reads text lines from a file.
    * @param {string} fileName
    *    Name of the file to be read

[Sebastian Noack, 2017/05/22 13:36:30]

Nit: This is inconsistent with how we wrap documentation everywhere else:

  * @param {type} argname beginning of the description goes here
                          subsequent lines are aligned with the above

[Wladimir Palant, 2017/05/22 13:46:31]

Yes, I am aware of that - and wrapping it this way is really awkward once you
get lengthy type names, there simply isn't much space left for the text.

[Sebastian Noack, 2017/05/22 13:49:52]

Adding Dave for a third opinion.

[kzar, 2017/05/22 14:00:41]

Well IIRC I've done it both ways depending on the repository and what the
reviewer asked me to do. I don't care too much either way to be honest, I find
both pretty clear.

[hub, 2017/05/23 12:31:50]

I copied (and proofed) these documentation comment from adblockplus' lib/io.js.
Including the formatting.

    * @param {TextSink} listener
    *    Function that will be called for each line in the file
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   readFromFile(fileName, listener)
   {
     return loadFile(fileName).then(entry =>
     {
       for (let line of entry.content)
         listener(line);

[Sebastian Noack, 2017/05/22 13:36:30]

Nit: Please use 2 (not 4) space indentation. However, is it even necessary to
wrap this line?

[Wladimir Palant, 2017/05/22 13:46:31]

This comment doesn't appear to match the line it has been added to...

[Sebastian Noack, 2017/05/22 13:49:52]

Sorry, I misread the code. For some reason I didn't notice the line above.
Please ignore this comment.

     });
   },
 
   /**
    * Writes text lines to a file.
    * @param {string} fileName
    *    Name of the file to be written
    * @param {Iterable.<string>} data
    *    An array-like or iterable object containing the lines (without line
    *    endings)
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   writeToFile(fileName, data)
   {
     return saveFile(fileName, data);
   },
 
   /**
    * Copies a file.
    * @param {string} fromFile
    *    Name of the file to be copied
    * @param {string} toFile
    *    Name of the file to be written, will be overwritten if exists
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   copyFile(fromFile, toFile)
   {
-    return loadFile(fromFile).then(entry =>
-    {
-      return saveFile(toFile, entry.content).then(resolve());
-    });
+    return loadFile(fromFile).then(entry => saveFile(toFile, entry.content));
   },
 
   /**
    * Renames a file.
    * @param {string} fromFile
    *    Name of the file to be renamed
    * @param {string} newName
    *    New file name, will be overwritten if exists
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   renameFile(fromFile, newName)
   {
     return loadFile(fromFile).then(entry =>
     {
-      ext.storage.set(fileToKey(newName), entry, resolve);
-    }).then(() =>
-    {

[Sebastian Noack, 2017/05/22 13:36:30]

The parentheses + return is redundant here.

[hub, 2017/05/23 12:31:50]

Done.

-      return removeFile(fromFile);
-    });
+      return new Promise((resolve, reject) =>
+      {
+        ext.storage.set(fileToKey(newName), entry, () =>
+        {
+          if (chrome.runtime.lastError)
+            reject(chrome.runtime.lastError.message);
+          else
+            resolve();
+        });
+      });
+    }).then(() => removeFile(fromFile));
   },
 
   /**
    * Removes a file.
    * @param {string} fileName
    *    Name of the file to be removed
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   removeFile(fileName)
@@ skipping 18 matching lines @@
         lastModified: entry.lastModified
       };
     }).catch(error =>
     {
       if (error.type == "NoSuchFile")
         return {exists: false};
       throw error;
     });
   }
 };