Simple question about package : why it doesn't work?

Question

My notebook can't load my package and I don't know why.

I called "testons.m" the file containing my package, I wrote inside it the following exemple code :

BeginPackage[ "Package`"]



MainFunction::usage = 
    "MainFunction[ x] computes a simple function."

  Begin[ "Private`"]

  MainFunction[ x_] :=
    Module[ {y},
      y = x^2;
      y + 1
    ]

  End[]

  EndPackage[]

I put it in the folder :C:\Users\Me\Dropbox\internship-2017\Mathematica\initialisation

I wrote in my working notebook :

AppendTo[$Path,
"C:\\Users\\Me\\Dropbox\\internship-2017\\Mathematica\\initialisation"]

And when I write later in the same notebook :

<< Package`

Mathematica answers me : "Get::noopen: Cannot open Package`."

I followed the exact instruction written here : https://reference.wolfram.com/workbench/index.jsp?topic=/com.wolfram.eclipse.help/html/tasks/applications/packages.html

Where is my mistake ?

Thanks

Answer 1

Thanks to the comments above I have solved the problem. I think it would be nice to summarise how to avoid it.

First :

We have to add the folder where the package is in the $Path variable. This folder can contain spaces in its name without problem.

We have to save a package as a package file in mathematica (.wl in the menu). The package filename cannot contain "_" (maybe other special letters wont work as well).

To ensure that the functions of the package are loaded, its cells has to be put as initialization cells : menu "cell->cell properties->initialization cell".

Next :

The package is called by its filename not by the string between BeginPackage["thestring`"] in the packagefile. Do not forget the "`", even if we are talking about the filename. For example if the package filename is "test.wl", we have to call it by writing : << test`

The package filename and the package name (the thing we write inside the bracket of BeginPackage) can be different.

After each modifications of package file, we have to load again the package to take in account thoose modifications.