Why You Should Always Pass Objects as Function Parameters in JavaScript https://medium.com/p/7fb7c5833dc6

getChartOptionsObj.spec.js

// @/__tests__/utils/getChartOptionsObj.spec.js
describe("@/utils/getChartOptionsObj", () => {
  const chartData = [1, 2, 3]
  const defaultChart = getDefaultChartObj({ chartData })

  it("passes along defaultChart only without extraOptions", () => {
    const output = getChartOptionsObj({ chartData })
    expect(output).toBe(defaultChart)
  })

  it("passes along defaults and extraOptions", () => {
    const extraOptions = {
      series: [
        {
          type: "gauge",
          pointer: {
            show: true,
          },
        },
      ],
    }
    const output = getChartOptionsObj({ defaultChart, extraOptions })
    expect(output).toBe({ ...defaults, ...extraOptions })
  })
})