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chore: merge Fix/742 migrate doctest to jest (#749)

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* Remove QuickSelect doctest

There are more Jest test cases already.

* Remove AverageMedian doctest

Already migrated to jest

* Migrate doctest for BinaryExponentiationRecursive.js

(also remove inline "main" test method)

* Migrate doctest for EulersTotient.js

(also remove inline "main" test method)

* Migrate doctest for PrimeFactors.js

(also remove inline "main" test method)

* Migrate doctest for BogoSort.js

Re-write prototype-polluting helper methods, too.

(also remove inline test driver code)

* Migrate doctest for BeadSort.js

(also remove inline test driver code)

* Migrate doctest for BucketSort.js

(also remove inline test driver code)

* Migrate doctest for CocktailShakerSort.js

(also remove inline test driver code)

* Migrate doctest for MergeSort.js

(also remove inline test driver code)

* Migrate doctest for QuickSort.js

(also remove inline test driver code)

* Migrate doctest for ReverseString.js

(also remove inline test driver code)

* Migrate doctest for ReverseString.js

* Migrate doctest for ValidateEmail.js

* Migrate doctest for ConwaysGameOfLife.js

(remove the animate code, too)

* Remove TernarySearch doctest

Already migrated to jest

* Migrate doctest for BubbleSort.js

(also remove inline test driver code)

* Remove doctest from CI and from dependencies

relates to #742
fixes #586

* Migrate doctest for RgbHsvConversion.js

* Add --fix option to "standard" npm script

* Migrate doctest for BreadthFirstSearch.js

(also remove inline test driver code)

* Migrate doctest for BreadthFirstShortestPath.js

(also remove inline test driver code)

* Migrate doctest for EulerMethod.js

(also remove inline test driver code)

Move manual test-code for plotting stuff in the browser in a distinct file, too. Those "*.manual-test.js" files are excluded from the UpdateDirectory.mjs script, as well.

* Migrate doctest for Mandelbrot.js

(also remove inline test driver code & moved manual drawing test into a *.manual-test.js)

* Migrate doctest for FloodFill.js

* Migrate doctest for KochSnowflake.js

(also move manual drawing test into a *.manual-test.js)

* Update npm lockfile

* Update README and COMMITTING with a few bits & bobs regarding testing & code quality
This commit is contained in:
Roland Hummel
2021-10-07 09:03:38 +02:00
committed by GitHub
parent 6eeb989930
commit b13b12e88c
53 changed files with 882 additions and 13514 deletions
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108
Recursive/KochSnowflake.js
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@ -1,34 +1,20 @@
/**
* The Koch snowflake is a fractal curve and one of the earliest fractals to have been described.
* The Koch snowflake can be built up iteratively, in a sequence of stages. The first stage is an
* equilateral triangle, and each successive stage is formed by adding outward bends to each side of
* the previous stage, making smaller equilateral triangles. This can be achieved through the
* following steps for each line: 1. divide the line segment into three segments of equal length. 2.
* draw an equilateral triangle that has the middle segment from step 1 as its base and points
* outward. 3. remove the line segment that is the base of the triangle from step 2. (description
* adapted from https://en.wikipedia.org/wiki/Koch_snowflake ) (for a more detailed explanation and
* an implementation in the Processing language, see
* https://natureofcode.com/book/chapter-8-fractals/ #84-the-koch-curve-and-the-arraylist-technique
* ).
*
* The Koch snowflake can be built up iteratively, in a sequence of stages. The first stage is an equilateral triangle,
* and each successive stage is formed by adding outward bends to each side of the previous stage, making smaller
* equilateral triangles. This can be achieved through the following steps for each line:
* 1. divide the line segment into three segments of equal length.
* 2. draw an equilateral triangle that has the middle segment from step 1 as its base and points outward.
* 3. remove the line segment that is the base of the triangle from step 2.
*
* (description adapted from https://en.wikipedia.org/wiki/Koch_snowflake)
* (for a more detailed explanation and an implementation in the Processing language, see
* https://natureofcode.com/book/chapter-8-fractals/ #84-the-koch-curve-and-the-arraylist-technique).
*/
/*
Doctests
Test iterate-method
> iterate([new Vector2(0, 0), new Vector2(1, 0)], 1)[0];
{"x": 0, "y": 0}
> iterate([new Vector2(0, 0), new Vector2(1, 0)], 1)[1];
{"x": 1/3, "y": 0}
> iterate([new Vector2(0, 0), new Vector2(1, 0)], 1)[2];
{"x": 1/2, "y": Math.sin(Math.PI / 3) / 3}
> iterate([new Vector2(0, 0), new Vector2(1, 0)], 1)[3];
{"x": 2/3, "y": 0}
> iterate([new Vector2(0, 0), new Vector2(1, 0)], 1)[4];
{"x": 1, "y": 0}
*/
/** Class to handle the vector calculations. */
class Vector2 {
export class Vector2 {
constructor (x, y) {
this.x = x
this.y = y
@ -87,66 +73,15 @@ class Vector2 {
}
/**
* Method to render the Koch snowflake to a canvas.
* Go through the number of iterations determined by the argument "steps".
*
* @param canvasWidth The width of the canvas.
* @param steps The number of iterations.
* @returns The canvas of the rendered Koch snowflake.
*/
function getKochSnowflake (canvasWidth = 600, steps = 5) {
if (canvasWidth <= 0) {
throw new Error('canvasWidth should be greater than zero')
}
const offsetX = canvasWidth / 10.0
const offsetY = canvasWidth / 3.7
const vector1 = new Vector2(offsetX, offsetY)
const vector2 =
new Vector2(canvasWidth / 2, Math.sin(Math.PI / 3) * canvasWidth * 0.8 + offsetY)
const vector3 = new Vector2(canvasWidth - offsetX, offsetY)
const initialVectors = []
initialVectors.push(vector1)
initialVectors.push(vector2)
initialVectors.push(vector3)
initialVectors.push(vector1)
const vectors = iterate(initialVectors, steps)
return drawToCanvas(vectors, canvasWidth, canvasWidth)
}
/**
* Utility-method to render the Koch snowflake to a canvas.
*
* @param vectors The vectors defining the edges to be rendered.
* @param canvasWidth The width of the canvas.
* @param canvasHeight The height of the canvas.
* @returns The canvas of the rendered edges.
*/
function drawToCanvas (vectors, canvasWidth, canvasHeight) {
const canvas = document.createElement('canvas')
canvas.width = canvasWidth
canvas.height = canvasHeight
// Draw the edges
const ctx = canvas.getContext('2d')
ctx.beginPath()
ctx.moveTo(vectors[0].x, vectors[0].y)
for (let i = 1; i < vectors.length; i++) {
ctx.lineTo(vectors[i].x, vectors[i].y)
}
ctx.stroke()
return canvas
}
/**
* Go through the number of iterations determined by the argument "steps". Be careful with high
* values (above 5) since the time to calculate increases exponentially.
* Be careful with high values (above 5) since the time to calculate increases exponentially.
*
* @param initialVectors The vectors composing the shape to which the algorithm is applied.
* @param steps The number of iterations.
* @returns The transformed vectors after the iteration-steps.
*/
function iterate (initialVectors, steps) {
export function iterate (initialVectors, steps) {
let vectors = initialVectors
for (let i = 0; i < steps; i++) {
vectors = iterationStep(vectors)
@ -156,9 +91,10 @@ function iterate (initialVectors, steps) {
}
/**
* Loops through each pair of adjacent vectors. Each line between two adjacent vectors is divided
* into 4 segments by adding 3 additional vectors in-between the original two vectors. The vector
* in the middle is constructed through a 60 degree rotation so it is bent outwards.
* Loops through each pair of adjacent vectors.
*
* Each line between two adjacent vectors is divided into 4 segments by adding 3 additional vectors in-between the
* original two vectors. The vector in the middle is constructed through a 60 degree rotation so it is bent outwards.
*
* @param vectors The vectors composing the shape to which the algorithm is applied.
* @returns The transformed vectors after the iteration-step.
@ -178,9 +114,3 @@ function iterationStep (vectors) {
newVectors.push(vectors[vectors.length - 1])
return newVectors
}
// plot the results if the script is executed in a browser with a window-object
if (typeof window !== 'undefined') {
const canvas = getKochSnowflake()
document.body.append(canvas)
}