utils/musicutils.js: Pretiffy,linting and JSDoc Documentation

[daksh4469]

Issue Reference: #2767, #2630, #2609

[daksh4469]

I have restructured the code as there were many errors of the type: used before it is defined.
I also had to make global variables writable to fix the errors.
This was a very big file, thus has to fix errors in phases and thus there are so many commits to fixing these errors.

Please Review @meganindya.

[ricknjacky]

cherry pick your commits, 14 commits for just one file is too much, I can see that at times you have even repeated your commit messages.

Slice them down a little bit, do a rebase.
It's easier to review if commits are clustered and not blown out of proportions into 2 digit numbers for just one file.

[daksh4469]

Thanks for the review @ricknjacky...
I didn't know how to check for lining errors earlier, but now I know. So, this will definitely not happen again.

[ricknjacky]

A paraphrase :-
Using modern, feature-rich IDEs/text-editors like Atom, Brackets, WebStorm, Sublime Text, Visual Studio Code, etc. makes life way easier. These come with a directory-tree explorer, and an integrated terminal, at the very least, while having support for plugins/extensions to expand their functionality.

Some (non-exhaustive) benefits of using these are syntax highlighting, warning/error annotations, formatting, auto-refactoring, tons of customizable keyboard shortcuts, etc.

Not a hard and fast rule, it's your call on which editor you chose to use as extensions are available in almost all of them, just a suggestion VSCode is best alternative out there.

[daksh4469]

I already use VSCode and had also added the ESLint extension but didn't know why it wasn't working. I also saw that the .eslintrc file was already present in our project repo.
Still don't know why it didn't work.
Do you know how to enable this? @ricknjacky @meganindya

[meganindya]

Gotta enable it ... right bottom corner

[daksh4469]

Thanks @meganindya ..... got it.

[meganindya]

This is huuuge

[daksh4469]

Yeah... and that's why it has this many linting errors and so many commits.....

[meganindya]

Pls run down what you've done. I can't follow.

[daksh4469]

Yeah..so what I did was firstly Pretiffied the file and added JSDoc documentation and removed the debug logs. Then when I pushed these commits,
there were many errors generated (around 450 including warnings). Now, these errors were of 5 types:

1. 'var' is not defined
2. 'var' was used before it was defined
3. 'var' is assigned to itself
4. Read-only global 'var' should not be modified
5. Unexpected lexical declaration in case block

• Now, to resolve error 1, all such variables were defined globally: /* global var */.
• This further generated errors of type 4, which I resolved by making them 'writable': /* global var: writable */.
• The error of type 3 was produced just once in the case of this line: keySignature = keySignature;.
  Thus. this line was removed as it didn't affect the functionality.
• Error 4 was most common in this file wherein a variable or a function would be defined below the part where it was being used. Here, I repositioned all the const to the top. For functions with this type of error, I moved such functions above their first occurrence of usage.
  Incorrect:

  function a(){
     b();
  }
  
  function b(){
   ......
  }
  

  After Correction:

  function b(){
     ......
  }
  
  function a(){
   b();
  }
  
  

  Now, one major problem I faced, which could not be resolved by the above method, was in the case of the functions numberToPitch(i, temperament, startPitch, offset) and getNoteFromInterval(pitch, interval) , as both these functions used the other one. This was of the type:

  function a(){
     b();
  }
  
  function b(){
     a();
  }
  

  So, to resolve this, I declared one of the functions above their usage. Example:

  let b;
  function a(){
     b();
  }
  
  
  b = function(){
     a();
  }
  

• Error 5 was just occurring due to the absence of curly braces in the definition of a case of a switch statement.
  Incorrect:

  case:
      .........
      .........
      
  

  Correct:

  case: {
       ........
       ........
  }
  

Since there were a huge number of functions in this file, It took a lot of commits to resolve all of them.

[ricknjacky]

you can close this PR,
I recently dealt with this file and it is linted, prettified etc (: