src/Form.ts

   1 import TaxReturn from './TaxReturn';
   2 import { Line } from './Line';
   3 import { InconsistencyError, NotFoundError } from './Errors';
   4
   5 export default abstract class Form<I = unknown> {
   6   private _lines: Line<any>[] = [];
   7   private _input?: I;
   8
   9   abstract get name(): string;
  10
  11   constructor(input?: I) {
  12     this._input = input;
  13     this.getLines().map(this.addLine.bind(this));
  14   }
  15
  16   protected abstract getLines(): Line<any>[];
  17
  18   private addLine(line: Line<any>) {
  19     if (line.form !== undefined) {
  20       throw new InconsistencyError('Line is already in a Form');
  21     }
  22     try {
  23       this.getLine(line.id);
  24     } catch {
  25       line.form = this;
  26       this._lines.push(line);
  27       return;
  28     }
  29     throw new InconsistencyError('Cannot add a line with a duplicate identifier');
  30   }
  31
  32   getLine(id: string): Line<any> {
  33     const lines = this._lines.filter(l => l.id === id);
  34     if (lines.length == 0) {
  35       throw new NotFoundError(id);
  36     }
  37     return lines[0];
  38   }
  39
  40   getValue<T>(tr: TaxReturn, id: string): T {
  41     const line: Line<T> = this.getLine(id);
  42     return line.value(tr);
  43   }
  44
  45   getInput<K extends keyof I>(name: K): I[K] {
  46     if (!(name in this._input)) {
  47       throw new NotFoundError(`No input with key ${name} on form ${this.name}`);
  48     }
  49     return this._input[name];
  50   }
  51 };
  52
  53 export interface SupportsMultipleCopies extends Form {
  54   aggregate(forms: Form[]): this;
  55 };
  56
  57 export function supportsMultipleCopies(f: object): f is SupportsMultipleCopies {
  58   return f instanceof Form && 'aggregate' in f;
  59 };