"Emulate" -native/file

Hello,

I am working on an app that utilizes data from a file stored on the device. Works.
My problem: For debugging purposes I need a way to load data from a local file from the development machine (Windows OS) and I have no idea how.
I can switch between both ways by evaluating the platform, but since Cordova isn’t available on the development machine, I don’t know how to access local files.

What exactly do you mean by “access”?
Also what do you mean by “on the development machine”? In the context of ionic serve?

yes, development machine means the browser context of ionic serve;
“access” means reading the content of a file.
In the context of the deployed app I can do

this.file.readAsText(this.file.externalRootDirectory, "Download/convertcsv.json")

this will not work in the context of ionic serve because cordova is not available.

a) Use the browser platform of Cordova, be aware that not all plugins support that one. Run the app via ionic cordova run browser then.
b) Look into input type file: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/file