I'm calling getNextPos from solution function and getting val,pos and dir. But my test case is failing " Cannot spy the getNextPos property because it is not a function; undefined given instead". I just want to test one function from another function and the return values. Here is app.js file
function getNextPos(grid, currPos, currDir, move) {
const nextDir = nextDirMap[currDir][move];
const [r, c] = currPos;
const maxRowLength = grid.length-1;
const maxColLength = grid[0].length-1;
switch (nextDir) {
case "north": {
if (r <= 0) {
cost = cost + (uncleardSquare * 3);
throw new CustomException("Unable to move, there is an attempt to navigate beyond the boundaries of the site.");
}
return {
val: grid[r - 1][c],
pos: [r - 1, c],
dir: "north"
};
}
}
function solution(grid, index, direction, bulldozerMove) {
div.innerText = "";
let currPos = index;
let currDir = direction;
bulldozerMove = bulldozerMove.toLowerCase();
let {
val,
pos,
dir
} = getNextPos(grid, currPos, currDir, bulldozerMove);
}
Here is the app.test.js file
const { getNextPos, solution} = require('./app');
const grid = [
["r", "o", "t", "t"],
["o", "r", "o", "t"],
["o", "o", "o", "t"],
];
describe("solution function", () => {
test('should call getNextPos', () => {
const spy = jest.spyOn(solution, 'getNextPos');
const isCalled = solution.getNextPos();
expect(spy).toHaveBeenCalled();
expect(isCalled).toBe(true);
spy.mockRestore();
})
})
It looks like you're mocking/spying getNextPos inside of the solution object, but in fact, solution is not an object, it's a function.
For example:
// calc.js
const calc = {
sum: (n1, n2) => n1 + n2
}
module.exports = { calc }
then in a test file:
import { calc } from './calc.js'
const sumSpy = jest.spyOn(calc, 'sum')
it('should pass because calc.sum has been mocked', () => {
sumSpy.mockReturnValue(20);
expect(calc.sum(5, 5)).toBe(20)
})
that works properly because I am spying a function inside an object. Maybe you can do a refactor to move stuff to separe things into objects