CellError does not provide localized error value that should be displayed in a cell

[wojciechczerniak]

Description

While working on integration we've noticed [1] that we have to map CellError.type to a human-readable string. Unfortunately, we can't use the translated error message then.

hyperformula/src/i18n/plPL.ts

Lines 42 to 50 in e696d1d

	errors: {
	DIV_BY_ZERO: '#DZIEL/0!',
	NAME: '#NAZWA?',
	VALUE: '#ARG!',
	NUM: '#LICZBA!',
	NA: '#N/A',
	CYCLE: '#CYKL!',
	REF: '#ADR!',
	},

This should be handled by the engine and exposed as the CellError class property.

hyperformula/src/Cell.ts

Lines 79 to 82 in e696d1d

	export class CellError {
	constructor(public readonly type: ErrorType) {
	}
	}

API Proposal

export class CellError {
  public readonly type: ErrorType
  public readonly message: string

  constructor(type, message = null) { 
    this.type = type;
    this.message = message;
  }
  
  /** 
    * Localized cell value that will be displayed in a worksheet cell renderer
    */
  public get value() {
    return getLocalizedErrorValue(this.type);
  }
}

At first I thought about naming it message property but #VALUE! error can have a custom message returned by the user [2]. So it would be cool to extend the CellError with one more readonly property:

constructor(public readonly type: ErrorType, public readonly message: string) { }

Error types

Name	Comments
#DIV/0!	Attempt to divide by zero, including division by an empty cell. ERROR.TYPE of 2 6.13.11
#NAME?	Unrecognized/deleted name. ERROR.TYPE of 5.
#N/A	Not available. ISNA() applied to this value will return TRUE. Lookup functions that failed, and NA(), return this value. ERROR.TYPE of 7.
#NULL!	Intersection of ranges produced zero cells. ERROR.TYPE of 1.
#NUM!	Failed to meet domain constraints (e.g., input was too large or too small). ERROR.TYPE of 6.
#REF!	Reference to invalid cell (e.g., beyond the application’s abilities). ERROR.TYPE of 4.
#VALUE!	Parameter is wrong type. ERROR.TYPE of 3.

Reference

[1] https://github.com/handsontable/handsontable/pull/6512/files#r352545073
[2] https://docs.microsoft.com/en-us/office/dev/add-ins/excel/custom-functions-errors

[voodoo11]

Done #151

[wojciechczerniak]

Thx 🏅