Added new area calculators (#428)

Maths/Area.js

@@ -0,0 +1,99 @@
+/*
+  Calculate the area of various shapes
+
+  Calculate the Surface Area of a Cube.
+  Example: surfaceAreaCube(1) will return 6
+  More about: https://en.wikipedia.org/wiki/Area#Surface_area
+ */
+const surfaceAreaCube = (sideLength) => {
+  validateNumericParam(sideLength, 'sideLength')
+  return (6.0 * sideLength ** 2.0)
+}
+
+/*
+  Calculate the Surface Area of a Sphere.
+  Wikipedia reference: https://en.wikipedia.org/wiki/Sphere
+  return 4 * pi * r^2
+*/
+const surfaceAreaSphere = (radius) => {
+  validateNumericParam(radius, 'radius')
+  return (4.0 * Math.PI * radius ** 2.0)
+}
+
+/*
+  Calculate the area of a rectangle
+  Wikipedia reference: https://en.wikipedia.org/wiki/Area#Quadrilateral_area
+  return width * length
+*/
+const areaRectangle = (length, width) => {
+  validateNumericParam(length, 'Length')
+  validateNumericParam(width, 'Width')
+  return (width * length)
+}
+
+/*
+  Calculate the area of a square
+*/
+const areaSquare = (sideLength) => {
+  validateNumericParam(sideLength, 'side length')
+  return (sideLength ** 2)
+}
+
+/*
+  Calculate the area of a triangle
+  Wikipedia reference: https://en.wikipedia.org/wiki/Area#Triangle_area
+  return base * height / 2
+*/
+const areaTriangle = (base, height) => {
+  validateNumericParam(base, 'Base')
+  validateNumericParam(height, 'Height')
+  return (base * height) / 2.0
+}
+
+/*
+  Calculate the area of a parallelogram
+  Wikipedia reference: https://en.wikipedia.org/wiki/Area#Dissection,_parallelograms,_and_triangles
+*/
+const areaParallelogram = (base, height) => {
+  validateNumericParam(base, 'Base')
+  validateNumericParam(height, 'Height')
+  return (base * height)
+}
+
+/*
+  Calculate the area of a trapezium
+*/
+const areaTrapezium = (base1, base2, height) => {
+  validateNumericParam(base1, 'Base One')
+  validateNumericParam(base2, 'Base Two')
+  validateNumericParam(height, 'Height')
+  return 1.0 / 2.0 * (base1 + base2) * height
+}
+
+/*
+  Calculate the area of a circle
+*/
+const areaCircle = (radius) => {
+  validateNumericParam(radius, 'Radius')
+  return (Math.PI * radius ** 2)
+}
+
+/*
+  Calculate the area of a rhombus
+  Wikipedia reference: https://en.wikipedia.org/wiki/Rhombus
+*/
+const areaRhombus = (diagonal1, diagonal2) => {
+  validateNumericParam(diagonal1, 'diagonal one')
+  validateNumericParam(diagonal2, 'diagonal two')
+  return (1 / 2 * diagonal1 * diagonal2)
+}
+
+const validateNumericParam = (param, paramName = 'param') => {
+  if (typeof param !== 'number') {
+    throw new TypeError('The ' + paramName + ' should be type Number')
+  } else if (param < 0) {
+    throw new Error('The ' + paramName + ' only accepts non-negative values')
+  }
+}
+
+export { surfaceAreaCube, surfaceAreaSphere, areaRectangle, areaSquare, areaTriangle, areaParallelogram, areaTrapezium, areaCircle, areaRhombus }

Maths/Area.test.js

@@ -0,0 +1,99 @@
+import * as area from './Area'
+
+describe('Testing surfaceAreaCube calculations', () => {
+  it('with natural number', () => {
+    const surfaceAreaOfOne = area.surfaceAreaCube(1.2)
+    const surfaceAreaOfThree = area.surfaceAreaCube(3)
+    expect(surfaceAreaOfOne).toBe(8.64)
+    expect(surfaceAreaOfThree).toBe(54)
+  })
+  it('with negative argument, expect throw', () => {
+    expect(() => area.surfaceAreaCube(-1)).toThrow()
+  })
+  it('with non-numeric argument, expect throw', () => {
+    expect(() => area.surfaceAreaCube('199')).toThrow()
+  })
+})
+describe('Testing surfaceAreaSphere calculations', () => {
+  it('with correct value', () => {
+    const calculateArea = area.surfaceAreaSphere(5)
+    const expected = 314.1592653589793
+    expect(calculateArea).toBe(expected)
+  })
+  it('with negative value, expect throw', () => {
+    expect(() => area.surfaceAreaSphere(-1)).toThrow()
+  })
+})
+describe('Testing areaRectangle calculations', () => {
+  it('with correct args', () => {
+    const areaRectangle = area.areaRectangle(2.5, 2)
+    expect(areaRectangle).toBe(5.0)
+  })
+  it('with incorrect args, expect throw', () => {
+    expect(() => area.areaRectangle(-1, 20)).toThrow()
+    expect(() => area.areaRectangle('1', 0)).toThrow()
+    expect(() => area.areaRectangle(23, -1)).toThrow()
+    expect(() => area.areaRectangle(23, 'zero')).toThrow()
+  })
+})
+describe('Testing areaSquare calculations', () => {
+  it('with correct args', () => {
+    const areaSquare = area.areaSquare(2.5)
+    expect(areaSquare).toBe(6.25)
+  })
+  it('with incorrect side length, expect throw', () => {
+    expect(() => area.areaSquare(-1)).toThrow()
+    expect(() => area.areaSquare('zero')).toThrow()
+  })
+})
+describe('Testing areaTriangle calculations', () => {
+  it('with correct args', () => {
+    const areaTriangle = area.areaTriangle(1.66, 3.44)
+    expect(areaTriangle).toBe(2.8552)
+  })
+  it('with incorrect base and height, expect throw', () => {
+    expect(() => area.areaTriangle(-1, 1)).toThrow()
+    expect(() => area.areaTriangle(9, 'zero')).toThrow()
+  })
+})
+describe('Testing areaParallelogram calculations', () => {
+  it('with correct args', () => {
+    const areaParallelogram = area.areaParallelogram(1.66, 3.44)
+    expect(areaParallelogram).toBe(5.7104)
+  })
+  it('with incorrect base and height, expect throw', () => {
+    expect(() => area.areaParallelogram(-1, 1)).toThrow()
+    expect(() => area.areaParallelogram(9, 'zero')).toThrow()
+  })
+})
+describe('Testing areaTrapezium calculations', () => {
+  it('with correct args', () => {
+    const areaTrapezium = area.areaTrapezium(1.66, 2.41, 4.1)
+    expect(areaTrapezium).toBe(8.3435)
+  })
+  it('with incorrect bases and height, expect throw', () => {
+    expect(() => area.areaTrapezium(-1, 1, 0)).toThrow()
+    expect(() => area.areaTrapezium(9, 'zero', 2)).toThrow()
+    expect(() => area.areaTrapezium(9, 1, 'seven')).toThrow()
+  })
+})
+describe('Testing areaCircle calculations', () => {
+  it('with correct args', () => {
+    const areaCircle = area.areaCircle(3.456)
+    expect(areaCircle).toBe(37.52298159254666)
+  })
+  it('with incorrect diagonal, expect throw', () => {
+    expect(() => area.areaCircle(-1)).toThrow()
+    expect(() => area.areaCircle('zero')).toThrow()
+  })
+})
+describe('Testing areaRhombus calculations', () => {
+  it('with correct args', () => {
+    const areaRhombus = area.areaRhombus(2.5, 2.0)
+    expect(areaRhombus).toBe(2.5)
+  })
+  it('with incorrect diagonals, expect throw', () => {
+    expect(() => area.areaRhombus(7, -1)).toThrow()
+    expect(() => area.areaRhombus('zero', 2)).toThrow()
+  })
+})