Typescript class objects functions and getters return blank when used in tags

[fsuk]

Tags which access functions / getters on objects from typescript classes resolve as blank.

export class MyData {
  public get id () :string {
    return '12345'
  }
}

  const lq = new Liquid()
  const data = new MyData()
  const result = await lq.parseAndRender('The ID is: {{id}}', data)
  //The ID is:

[fsuk]

Workaround for functions:

export class MyData {
 getId = () => {
    return '12345'
  }
}

[fsuk]

Workaround for getters:

export class MyData {
  constructor () {
    Object.defineProperties(this, {
      id: {
        get: this._getId,
        enumerable: true
      }
    })
  }

  id: string
  private _getId (): string {
    return '12345'
  }
}

Note id: string so typescript knows it exists

[harttle]

Hey @fsuk ,

ES6 class getters are on __proto__, which is not allowed to read from by default, you'll need to set ownPropertyOnly to false to allow that. This should work for you:

    class MyData {
      public get id () :string {
        return '12345'
      }
    }
    const liquid = new Liquid({ ownPropertyOnly: false })
    const data = new MyData()
    const result = await liquid.parseAndRender('The ID is: {{id}}', data)
    expect(result).to.equal('The ID is: 12345')

For further discussion that may justify "reading from getters being an exception even ownPropertyOnly set to true", it can be implemented so in theory utilizing Object.getOwnPropertyDescriptor(), but that can be too heavy to check property descriptor each time reading a property. Since the implementation requires reading property descriptor of data.__proto__, I believe you should set ownPropertyOnly to false to explicitly tell LiquidJS that you're using Objects as context.

[fsuk]

According to the docs ownPropertyOnly defaults to false and I have not set it to true

[harttle]

Sorry the docs is outdated, the default value is changed to true since v10.0.0, I'm updating the docs.