src/Line.ts

   1 import TaxReturn from './TaxReturn';
   2 import Form from './Form';
   3
   4 export abstract class Line<T> {
   5   private _description?: string;
   6
   7   _id: string;  // _id is set by Form.init().
   8   form: Form<any, any>;  // Set by Form.init();
   9
  10   constructor(description?: string) {
  11     this._description = description;
  12   }
  13
  14   get id(): string {
  15     return this._id;
  16   }
  17
  18   get description(): string {
  19     return this._description;
  20   }
  21
  22   abstract value(tr: TaxReturn): T;
  23 };
  24
  25 type ComputeFunc<T> = (tr: TaxReturn, l: ComputedLine<T>) => T;
  26
  27 export class ComputedLine<T> extends Line<T> {
  28   private _compute: ComputeFunc<T>;
  29
  30   constructor(compute: ComputeFunc<T>, description?: string) {
  31     super(description);
  32     this._compute = compute;
  33   }
  34
  35   value(tr: TaxReturn): T {
  36     return this._compute(tr, this);
  37   }
  38 };
  39
  40 export class ReferenceLine<T> extends Line<T> {
  41   private _form: string;
  42   private _line: string;
  43
  44   constructor(form: string, line: string, description?: string) {
  45     super(description || `Reference F${form}.L${line}`);
  46     this._form = form;
  47     this._line = line;
  48   }
  49
  50   value(tr: TaxReturn): T {
  51     return tr.getForm(this._form).getLine(this._line).value(tr);
  52   }
  53 };
  54
  55 export class InputLine<U = unknown, T extends keyof U = any> extends Line<U[T]> {
  56   private _input: T;
  57
  58   form: Form<any, U>;
  59
  60   constructor(input: T, description?: string) {
  61     super(description || `Input from ${input}`);
  62     this._input = input;
  63   }
  64
  65   value(tr: TaxReturn): U[T] {
  66     return this.form.getInput<T>(this._input);
  67   }
  68 };
  69
  70 export class AccumulatorLine extends Line<number> {
  71   private _form: string;
  72   private _line: string;
  73
  74   constructor(form: string, line: string, description?: string) {
  75     super(description || `Accumulator F${form}.L${line}`);
  76     this._form = form;
  77     this._line = line;
  78   }
  79
  80   value(tr: TaxReturn): number {
  81     const forms = tr.getForms(this._form);
  82     const reducer = (acc: number, curr: Form<any>) => acc + (curr.getValue(tr, this._line) as number);
  83     return forms.reduce(reducer, 0);
  84   }
  85 };