Function checkInput

src/material/slider/slider.spec.ts:48–92

(
    input: MatSliderThumb,
    {
      min,
      max,
      value,
      translateX,
      width,
      step,
    }: {min: number; max: number; value: number; translateX: number; width?: number; step?: number},
  )

  }

  function checkInput(
    input: MatSliderThumb,
    {
      min,
      max,
      value,
      translateX,
      width,
      step,
    }: {min: number; max: number; value: number; translateX: number; width?: number; step?: number},
  ): void {
    expect(input.min).withContext('min').toBe(min);
    expect(input.max).withContext('max').toBe(max);
    expect(input.value).withContext('value').toBe(value);

    // The discrepancy between the "ideal" and "actual" translateX comes from
    // the 3px offset from the start & end of the slider track to the first
    // and last tick marks.
    //
    // The "actual" translateX is calculated based on a slider that is 6px
    // smaller than the width of the slider. Using this "actual" translateX in
    // tests would make it even more difficult than it already is to tell if
    // the translateX is off, so we abstract things in here so tests can be
    // more intuitive.
    //
    // The most clear way to compare the two tx's is to just turn them into
    // percentages by dividing by their (total height) / 100.
    const idealTXPercentage = Math.round(translateX / 3);
    const actualTXPercentage = Math.round((input.translateX - 3) / 2.94);
    expect(actualTXPercentage)
      .withContext(`translateX: ${input.translateX} should be close to ${translateX}`)
      .toBe(idealTXPercentage);
    if (step !== undefined) {
      expect(input.step).withContext('step').toBe(step);
    }
    if (width !== undefined) {
      const realWidth = parseInt(
        (input as MatSliderRangeThumb)._hostElement.style.width.match(/\d+/)![0],
        10,
      );
      expect(realWidth)
        .withContext('width')
        .toBeCloseTo((300 * width) / 100 + 16, 0);
    }
  }

  // Note that this test is outside of the other `describe` blocks, because they all run
  // `detectChanges` in the `beforeEach` and we're testing specifically what happens if it