1-get-angle-type.js

// Implement a function getAngleType
//
// When given an angle in degrees, it should return a string indicating the type of angle:
// - "Acute angle" for angles greater than 0° and less than 90°
// - "Right angle" for exactly 90°
// - "Obtuse angle" for angles greater than 90° and less than 180°
// - "Straight angle" for exactly 180°
// - "Reflex angle" for angles greater than 180° and less than 360°
// - "Invalid angle" for angles outside the valid range.

// Assumption: The parameter is a valid number. (You do not need to handle non-numeric inputs.)

// Acceptance criteria:
// After you have implemented the function, write tests to cover all the cases, and
// execute the code to ensure all tests pass.

function getAngleType(angle) {
  if (angle <= 0 || angle >= 360) {
    return "Invalid angle";
  } else if (angle < 90) {
    return "Acute angle";
  } else if (angle === 90) {
    return "Right angle";
  } else if (angle < 180) {
    return "Obtuse angle";
  } else if (angle === 180) {
    return "Straight angle";
  } else {
    return "Reflex angle";
  }
}

// The line below allows us to load the getAngleType function into tests in other files.
// This will be useful in the "rewrite tests with jest" step.
module.exports = getAngleType;

// This helper function is written to make our assertions easier to read.
// If the actual output matches the target output, the test will pass
function assertEquals(actualOutput, targetOutput) {
  console.assert(
    actualOutput === targetOutput,
    `Expected ${actualOutput} to equal ${targetOutput}`
  );
}

// Tests to cover all cases, including boundary and invalid cases.
console.log("Starting tests...");

// 1. Right angle
const right = getAngleType(90);
assertEquals(right, "Right angle");

// 2. Acute angle
const acute = getAngleType(45);
assertEquals(acute, "Acute angle");

// 3. Obtuse angle
const obtuse = getAngleType(120);
assertEquals(obtuse, "Obtuse angle");

// 4. Straight angle
const straight = getAngleType(180);
assertEquals(straight, "Straight angle");

// 5. Reflex angle
const reflex = getAngleType(250);
assertEquals(reflex, "Reflex angle");

// 6. Invalid angle - zero
const invalidZero = getAngleType(0);
assertEquals(invalidZero, "Invalid angle");

// 7. Invalid angle - negative
const invalidNegative = getAngleType(-50);
assertEquals(invalidNegative, "Invalid angle");

// 8. Invalid angle - 360 or more
const invalidTooBig = getAngleType(360);
assertEquals(invalidTooBig, "Invalid angle");

console.log("All tests completed!");