awesome-cordova-plugins/scripts/build/transformers/methods.ts

import * as ts from 'typescript';
import { Logger } from '../../logger';
import {
  convertValueToLiteral,
  getDecorator,
  getDecoratorArgs,
  getDecoratorName,
  getMethodsForDecorator,
} from '../helpers';

export function transformMethod(method: ts.MethodDeclaration) {
  if (!method) return;

  const decorator = getDecorator(method),
    decoratorName = getDecoratorName(decorator),
    decoratorArgs = getDecoratorArgs(decorator);

  try {
    return ts.createMethod(
      undefined,
      undefined,
      undefined,
      method.name,
      undefined,
      method.typeParameters,
      method.parameters,
      method.type,
      ts.createBlock([ts.createReturn(getMethodBlock(method, decoratorName, decoratorArgs))])
    );
  } catch (e) {
    Logger.error('Error transforming method: ' + (method.name as any).text);
    Logger.error(e.message);
  }
}

function getMethodBlock(method: ts.MethodDeclaration, decoratorName: string, decoratorArgs: any): ts.Expression {
  const decoratorMethod = getMethodsForDecorator(decoratorName)[0];

  switch (decoratorName) {
    case 'CordovaCheck':
    case 'InstanceCheck':
      // TODO remove function wrapper
      return ts.createImmediatelyInvokedArrowFunction([
        ts.createIf(
          ts.createBinary(
            ts.createCall(ts.createIdentifier(decoratorMethod), undefined, [ts.createThis()]),
            ts.SyntaxKind.EqualsEqualsEqualsToken,
            ts.createTrue()
          ),
          method.body
        ),
      ]);

    default:
      return ts.createCall(ts.createIdentifier(decoratorMethod), undefined, [
        ts.createThis(),
        ts.createLiteral((method.name as any).text),
        convertValueToLiteral(decoratorArgs),
        ts.createIdentifier('arguments'),
      ]);
  }
}