js__typescript__jest/__tests__/base.spec.ts

import {
  BinaryOperation,
  BinaryOperators,
  evaluate,
  sampleFunction,
} from "../src";

describe("This is a simple test", () => {
  test("Check the sampleFunction function", () => {
    const actual = sampleFunction("hello");
    const expected = "hellohello";
    expect(actual).toEqual(expected);
  });
});

describe("Simple expression tests", () => {
  test("Check literal value", () => {
    expect(evaluate({ type: "literal", value: 5 })).toBeCloseTo(5);
  });

  test("Check addition", () => {
    const expr: BinaryOperation = bin("+", 5, 10);
    expect(evaluate(expr)).toBeCloseTo(15);
  });

  test("Check subtraction", () => {
    const expr: BinaryOperation = bin("-", 5, 10);
    expect(evaluate(expr)).toBeCloseTo(-5);
  });

  test("Check multiplication", () => {
    const expr: BinaryOperation = bin("*", 5, 10);
    expect(evaluate(expr)).toBeCloseTo(50);
  });

  test("Check division", () => {
    const expr: BinaryOperation = bin("/", 10, 5);
    expect(evaluate(expr)).toBeCloseTo(2);
  });
});

function bin(op: BinaryOperators, x: number, y: number): BinaryOperation {
  return {
    left: {
      type: "literal",
      value: x,
    },
    operator: op,
    right: {
      type: "literal",
      value: y,
    },
    type: "binary",
  };
}