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

* 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

Recursive/KochSnowflake.manual-test.js

@@ -0,0 +1,58 @@
+import { Vector2, iterate } from './KochSnowflake'
+
+/**
+ * Method to render the Koch snowflake to a canvas.
+ *
+ * @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
+}
+
+// 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)
+}