Terminal abstract class

[ashwinkjoseph]

Task Description
Set up an abstract class for the terminal which should define the methods and the APIs for a terminal in TPF learning section's tutorials.
In the context of TPF, a terminal should have the following behaviour:

• Accept an HTML Div Element and mount to it while initializing
• Accept custom styles when initializing and should also allow for customization after initialization.
• Should allow the user to type and execute commands
• Should accept a callback function during initialization which will be called whenever a command is executed.
• Should accept an instance of a file system while initializing and use it for executing filesystem related commands.
• Should keep track of previously executed commands
• Should allow for navigating across previously executed commands.
• Should have a method for toggling the state of the waiting/executing state of the terminal.
• Should have a method for programmatically writing to the terminal via external programs (basically for displaying the output of executed commands)
• Should have a method for minimizing
• Should have a method for closing

Acceptance criteria for task

• Check that the implementations of the class have a private method named mount
• Check that the implementations of the class have a public method named style.
• Check that the implementations of the class have a private variable named filesystem
• Check that the implementations of the class have a public method named toggleWaitignState
• Check that the implementations of the class have a public method named writeToOut
• Check that the implementations of the class have a public method method minimize
• Check that the implementations of the class have a public method named close

Additional context
Shiva Raju has a very good implementation for the abstract class in Javascript. Refer to this if you are unsure about how to do it.

class PFEditorAbstractClass {
    constructor() {
        if (this.constructor === PFEditorAbstractClass) {
            throw new TypeError('Abstract class "PFEditorAbstractClass" cannot be instantiated directly.');
        }
		
		//abstract method for mounting an Editor into a DOM Elemement must be implemented
		if(!typeof this.mountEditorToDOMElement === 'function'){
			throw new TypeError('Classes implementing PFEditorAbstractClass class must implement all its methods');
		}

                 if (this.content === undefined) {
                         throw new TypeError('Classes implementing PFEditorAbstractClass must have the content as an attribute')
                 }
		
		//abstract method for storing one or more variables in local storage must be implemented
		if(!this.saveContent === 'function'){
			throw new TypeError('Classes implementing PFEditorAbstractClass class must implement all its methods');
		}]
		
		//abstract method for retrieving one or more variables from local storage must be implemented
		if(!typeof this. this.getContent === 'function'){
			throw new TypeError('Classes implementing PFEditorAbstractClass class must implement all its methods');
		}
		
		//abstract method for closing the Editor after necessary cleanup operations must be implemented
		if(!typeof this.closeEditor === 'function'){
			throw new TypeError('Classes implementing PFEditorAbstractClass class must implement all its methods');
		}
		
		//abstract method for minimizing the Editor after necessary saving operations must be implemented
		if(!typeof this.minimizeEditor === 'function'){
			throw new TypeError('Classes implementing PFEditorAbstractClass class must implement all its methods');
		}
    }
  }