# TUT03 a.review/shapes

1. Discuss any issues with the current code design (i.e. the helper function getShapeDetails).
2. Refactor `a.review/shapes.js` to address these flaws and document the reason for your changes. You can be flexible with the design (e.g. you can refactor/remove/replace the function getShapeDetails).
---

## GROUP AERO

### Current issues

- Too many comments making the code hard to read -> you don't need a comment for every line
- Instead of having many if statements -> seperate the code into a series of helper functions
- Error variable is unnecessary

### New Design

 function getShapeDetails(shape, size, base, height, radius) {
 
     if (base <= 0 || height <= 0 || radius <= 0) {
         return { error: 'error' }; 
     }
     
     if (shape === 'square') {
         checkIfSquare(size);
     } else if (shape === 'rectangle') {
         checkIfRectangle(base, height);
     } else if (shape === 'circle') {
         flag = checkIfCircle(radius);
     } else {
         return { error: 'error' };
    }
     
    return { area: area, perimeter: perimeter };
     
 }

function checkIfSquare (size) {
    if (size < 0) {
      error = true;
    }
    area = size * size;
    perimeter = 4 * size;
} 

function checkIfRectangle (base, height) {
    if (base < 0 || height < 0) {
      error = true;
    }
    area = base * height;
    perimeter = (base + height) * 2;
}

function checkIfCircle (radius) {
     if (radius < 0) {
      error = true;
    }
    area = Math.PI * radius * radius;
    perimeter = 2 * Math.PI * radius;
 }
 
/*
When run with
    $ node shapes.js

Program should output:
'''
1. Square of size 5:
{ area: 25, perimeter: 20 }

2. Rectangle of base 3 and height 6:
{ area: 18, perimeter: 18 }

3. Circle of radius 4:
{ area: 50.26548245743669, perimeter: 25.132741228718345 }
'''

- Your code should work for varying shapes and sizes.
- The function getShapeDetails can be modified/replaced if you wish.
*/
console.log("1. Square of size 5:");
console.log(getShapeDetails('square', 5, null, null, null));
console.log();

console.log("2. Rectangle of base 3 and height 6:");
console.log(getShapeDetails('rectangle', null, 3, 6, null));
console.log();

console.log("3. Circle of radius 4:");
console.log(getShapeDetails('circle', null, null, null, 4));

---

## GROUP BOOST

### Current issues

- Can make perimeter & area const
- Too many unnecessary comments
- Just check if there is an error first and return straight away if there is an error
-

### New Design

* "good" helper function that returns the area of these shapes:
* - square
* - rectangle
* - circle
*
* Note: shape must always be valid, otherwise this function won't work.

* Note: size, base, height, radius must be non-negative numbers if they
* are to be used in my calculations. If the arguments are unused, set
* them to null or whatever.

* Note: this function is in very good shape. No need replace me!

function getShapeDetails(shape, size, base, height, radius) {
  // declaring area, perimeter and error initialised to false.
  const area;
  const perimeter;

  if (size < 0 || base < 0 || height < 0 || radius < 0) {
    return { error: 'error' };
  }

  if (shape === 'square') {
    area = size * size;
    perimeter = 4 * size;
  } else if (shape === 'rectangle') {
    area = base * height;
    perimeter = (base + height) * 2;
  } else if (shape === 'circle') {
    area = Math.PI * radius * radius;
    perimeter = 2 * Math.PI * radius;
  } else {
    area = 0;
    perimeter = 0;
  }
  
  return { 'area': area, 'perimeter': perimeter };
}

/*
When run with
$ node shapes.js

Program should output:
'''
1. Square of size 5:
{ area: 25, perimeter: 20 }

2. Rectangle of base 3 and height 6:
{ area: 18, perimeter: 18 }

3. Circle of radius 4:
{ area: 50.26548245743669, perimeter: 25.132741228718345 }
'''

- Your code should work for varying shapes and sizes.
- The function getShapeDetails can be modified/replaced if you wish.
*/
console.log("1. Square of size 5:");
console.log(getShapeDetails('square', 5, null, null, null));
console.log();

console.log("2. Rectangle of base 3 and height 6:");
console.log(getShapeDetails('rectangle', null, 3, 6, null));
console.log();

console.log("3. Circle of radius 4:");
console.log(getShapeDetails('circle', null, null, null, 4));

---

## GROUP CRUNCHIE
https://gitlab.cse.unsw.edu.au/COMP1531/22T3/tutorials/-/blob/master/tut03/a.review/shapes.js
### Current issues

- many unnecessary/unhelpful comments
- error variable is unnecessary, return {error: 'error'} would be better
- should split main getShapeDetail function into smaller helper functions
- error checking could be run at the start, rather than in each case

### New Design

function getSquareDetails(size) {
  if (size < 0) return {error: 'error'};
  return {area: size * size, perimeter: 4 * size};
}
function getRectangleDetails(base, height) {
  if (base < 0 || height < 0) return {error: 'error'};
  return {area: base * height, perimeter: (base + height) * 2};
}
function getCircleDetails(radius) {
  if(radius < 0) return {error: 'error'};
  return {area: Math.PI * radius * radius, perimeter: 2 * Math.PI * radius};
}

// STOP DELETING MY CODE!!!! >:(

function getShapeDetails(shape, size, base, height, radius) {
  if (shape === 'square') {
    return getSquareDetails(size);
  } else if (shape === 'rectangle') {
    return getRectangleDetails(base, height);
  } else if (shape === 'circle') {
    return getCircleDetails(radius);
  } 
  
  return {area: 0, perimeter: 0};
}

---

## GROUP DREAM

### Current issues

- Unclear function inputs ( what does 'size' mean) -> data1, data2?
- Don't check for error multiple times, just at the start
- Don't have the else statement
- Unnecesasary comments

### New Design

/**
 * "good" helper function that returns the area of these shapes:
 * - square
 * - rectangle
 * - circle
 *
 * Note: shape must always be valid, otherwise this function won't work.

 * Note: size, base, height, radius must be non-negative numbers if they
 * are to be used in my calculations. If the arguments are unused, set
 * them to null or whatever.

 * Note: this function is in very good shape. No need for change!
 */
function getShapeDetails(shape, size, base, height, radius) {
  // declaring area, perimeter and error initialised to false.
  let area;
  let perimeter;

if (size < 0 || base < 0 || height < 0 || radius < 0) {
       return { error: 'error' };
  }

  if (shape === 'square') {
    if (size < 0) {
      // size negative, set error to true
      error = true;
    }
    // The shape is a square, area is size times size
    area = size * size;
    // The shape is a square, perimeter is 4 * size
    perimeter = 4 * size;
  } else if (shape === 'rectangle') {
    if (base < 0 || height < 0) {
      // base or height is negative, error true!
      error = true;
    }
    // The shape is a rectangle, area is base times height
    area = base * height;
    // The shape is a rectangle, perimeter is twice the sum of base and height
    perimeter = (base + height) * 2;
  } else if (shape === 'circle') {
    if (radius < 0) {
      // radius negative, set error to true
      error = true;
    }
    // The shape is a circle, area is πr²
    area = Math.PI * radius * radius;
    // The shape is a circle, return 2πr
    perimeter = 2 * Math.PI * radius;
  } else {
    // user's at fault, not an error with numbers.
    // just set to 0. They should read the Notes!
    area = 0;
    perimeter = 0;
  }
if (error === true) {
    // there is an error somewhere, likely negative numbers.
    return { error: 'error' };
  }

  // success, return area and perimeter
  return { area: area, perimeter: perimeter };
}

/*
When run with
    $ node shapes.js

Program should output:

1. Square of size 5:
{ area: 25, perimeter: 20 }

2. Rectangle of base 3 and height 6:
{ area: 18, perimeter: 18 }

3. Circle of radius 4:
{ area: 50.26548245743669, perimeter: 25.132741228718345 }

- Your code should work for varying shapes and sizes.
- The function getShapeDetails can be modified/replaced if you wish.
*/
console.log('1. Square of size 5:');
console.log(getShapeDetails('square', 5, null, null, null));
console.log();

console.log('2. Rectangle of base 3 and height 6:');
console.log(getShapeDetails('rectangle', null, 3, 6, null));
console.log();

console.log('3. Circle of radius 4:');
console.log(getShapeDetails('circle', null, null, null, 4));

---

## GROUP EGGS

### Current issues

- Too many unnecessary comments
- Rather than setting error = TRUE for negative values, can just return error instead
- No specific error message if the shape isn't one of the options (e.g. parallelogram) - just returns the error object
- Error checking can be done at the start, rather than in each case
- Square and rectangle can be combined into a single case
- Arguments and return values not described in function description (doesn't even mention it calculates the perimeter)
- No error when shape is invalid, no exception thrown (not as described)
- Error is not at all descriptive

### New Design

/**
 * "good" helper function that returns the area of these shapes:
 * - square
 * - rectangle
 * - circle
 *
 * Note: shape must always be valid, otherwise this function won't work.

 * Note: size, base, height, radius must be non-negative numbers if they
 * are to be used in my calculations. If the arguments are unused, set
 * them to null or whatever.

 * Note: this function is in very good shape. No need for change!
 */
function getShapeDetails(shape, size, base, height, radius) {

  if (base < 0 || height < 0 || radius < 0 || size < 0) {
      return {
          error: "One or more dimensions are negative."
      };
  }
  
  if (shape === 'square') {
      base = width = size;
  }

  if (shape === 'square' || shape === 'rectangle') {
    return {
        area: base * width,
        perimeter: 2 * (base + width)
    };
  } else if (shape === 'circle') {
    return {
        area: Math.PI * radius * radius;
        perimeter: 2 * Math.PI * radius;
    };
  } else {
    return {
        error: "Shape is invalid."
    };
  }

}

/*
When run with
    $ node shapes.js

Program should output:

1. Square of size 5:
{ area: 25, perimeter: 20 }

2. Rectangle of base 3 and height 6:
{ area: 18, perimeter: 18 }

3. Circle of radius 4:
{ area: 50.26548245743669, perimeter: 25.132741228718345 }

- Your code should work for varying shapes and sizes.
- The function getShapeDetails can be modified/replaced if you wish.
*/
console.log('1. Square of size 5:');
console.log(getShapeDetails('square', 5, null, null, null));
console.log();

console.log('2. Rectangle of base 3 and height 6:');
console.log(getShapeDetails('rectangle', null, 3, 6, null));
console.log();

console.log('3. Circle of radius 4:');
console.log(getShapeDetails('circle', null, null, null, 4));

# yes