FloodFill.test.js

import { breadthFirstSearch, depthFirstSearch } from '../FloodFill'

// some constants
const black = [0, 0, 0]
const green = [0, 255, 0]
const violet = [255, 0, 255]
const white = [255, 255, 255]
const orange = [255, 128, 0]

describe('FloodFill', () => {
  it('should calculate the correct colors using breadth-first approach', () => {
    expect(testBreadthFirst([1, 1], green, orange, [1, 1])).toEqual(orange)
    expect(testBreadthFirst([1, 1], green, orange, [0, 1])).toEqual(violet)
    expect(testBreadthFirst([1, 1], green, orange, [6, 4])).toEqual(white)
  })

  it('should calculate the correct colors using depth-first approach', () => {
    expect(testDepthFirst([1, 1], green, orange, [1, 1])).toEqual(orange)
    expect(testDepthFirst([1, 1], green, orange, [0, 1])).toEqual(violet)
    expect(testDepthFirst([1, 1], green, orange, [6, 4])).toEqual(white)
  })
})

/**
 * Utility-function to test the function "breadthFirstSearch".
 *
 * @param fillLocation The start location on the image where the flood fill is applied.
 * @param targetColor The old color to be replaced.
 * @param replacementColor The new color to replace the old one.
 * @param testLocation The location of the color to be checked.
 * @return The color at testLocation.
 */
function testBreadthFirst (fillLocation, targetColor, replacementColor, testLocation) {
  const rgbData = generateTestRgbData()
  breadthFirstSearch(rgbData, fillLocation, targetColor, replacementColor)
  return rgbData[testLocation[0]][testLocation[1]]
}

/**
 * Utility-function to test the function "depthFirstSearch".
 *
 * @param fillLocation The start location on the image where the flood fill is applied.
 * @param targetColor The old color to be replaced.
 * @param replacementColor The new color to replace the old one.
 * @param testLocation The location of the color to be checked.
 * @return The color at testLocation.
 */
function testDepthFirst (fillLocation, targetColor, replacementColor, testLocation) {// eslint-disable-line
  const rgbData = generateTestRgbData()
  depthFirstSearch(rgbData, fillLocation, targetColor, replacementColor)
  return rgbData[testLocation[0]][testLocation[1]]
}

/**
 * Generates the rgbData-matrix for the tests.
 *
 * @return example rgbData-matrix.
 */
function generateTestRgbData () {
  const layout = [
    [violet, violet, green, green, black, green, green],
    [violet, green, green, black, green, green, green],
    [green, green, green, black, green, green, green],
    [black, black, green, black, white, white, green],
    [violet, violet, black, violet, violet, white, white],
    [green, green, green, violet, violet, violet, violet],
    [violet, violet, violet, violet, violet, violet, violet]
  ]

  // transpose layout-matrix so the x-index comes before the y-index
  const transposed = []
  for (let x = 0; x < layout[0].length; x++) {
    transposed[x] = []
    for (let y = 0; y < layout.length; y++) {
      transposed[x][y] = layout[y][x]
    }
  }

  return transposed
}