feat: some unit tests for some more utility functions. (#12)

src/math.js

@@ -0,0 +1,19 @@
+/**
+ * Maps a number between a certain range offset by minAllowed.
+ *
+ * @param {number} n The number to map to a range.
+ * @param {number} minAllowed The minimum allowed for the range.
+ * @param {number} maxAllowed The maximum allowed for the range.
+ * @param {number} min The minimum value for the number.
+ * @param {number} max The maximum value for the number.
+ * @return {number} A number within the projected range.
+ */
+export function mapBetween(n, minAllowed, maxAllowed, min, max) {
+  // TODO: This function has been refactored and moved into this file as is
+  // It has yet to be checked for accuracy and validation has to be added.
+  const numerator = ((maxAllowed - minAllowed) * (n - min));
+  const denominator = (max - min);
+  return (
+    numerator / denominator + minAllowed
+  );
+}

src/math.test.js

@@ -0,0 +1,26 @@
+import { mapBetween } from './math';
+
+describe('mapBetween', () => {
+  test('should map the number within the allowable range', () => {
+    expect(mapBetween(4, 0, 5, 1, 3)).toEqual(7.5);
+
+    expect(mapBetween(4, 2, 5, 1, 3)).toEqual(6.5);
+    expect(mapBetween(4, 0, 4, 1, 3)).toEqual(6);
+    expect(mapBetween(4, 0, 5, 4, 3)).toEqual(0);
+  });
+
+  test('should map the number within the allowable range', () => {
+    expect(mapBetween(1, 0, 5, 1, 3)).toEqual(0);
+    expect(mapBetween(2, 0, 5, 1, 3)).toEqual(2.5);
+    expect(mapBetween(3, 0, 5, 1, 3)).toEqual(5);
+    expect(mapBetween(4, 0, 5, 1, 3)).toEqual(7.5);
+    expect(mapBetween(5, 0, 5, 1, 3)).toEqual(10);
+  });
+
+  // FIXME: Are we sure this function maps a number within an allowable range correctly?
+  test('should map the number within the allowable range (bad cases?)', () => {
+    expect(mapBetween(-2, 0, 5, 1, 3)).toEqual(-7.5);
+    expect(mapBetween(-1, 0, 5, 1, 3)).toEqual(-5);
+    expect(mapBetween(0, 0, 5, 1, 3)).toEqual(-2.5);
+  });
+});

src/radial_gauge.js

@@ -2,6 +2,8 @@ import React, {useEffect} from 'react';
 import * as d3 from 'd3';
 import SSF from 'ssf';
 // import { configs } from 'eslint-plugin-prettier';
+import {mapBetween} from './math';
+import {getLabel} from './string';
 
 const RadialGauge = props => {
   useEffect(() => {
@@ -10,12 +12,6 @@ const RadialGauge = props => {
   return <div className="viz" />;
 };
 
-function mapBetween(currentNum, minAllowed, maxAllowed, min, max) {
-  return (
-    ((maxAllowed - minAllowed) * (currentNum - min)) / (max - min) + minAllowed
-  );
-}
-
 function wrap(text, width) {
   text.each(function () {
     var text = d3.select(this),
@@ -51,20 +47,6 @@ function wrap(text, width) {
   });
 }
 
-function getLabel(rule, value, label, override) {
-  // console.log(rule, value, label, override)
-  label = override === '' ? label : override;
-  if (rule === 'value') {
-    return `${value}`;
-  } else if (rule === 'label') {
-    return `${label}`;
-  } else if (rule === 'both') {
-    return `${value} ${label}`;
-  } else if (rule === 'none') {
-    return ``;
-  }
-}
-
 const drawRadial = props => {
   let limiting_aspect = props.w < props.h ? 'vw' : 'vh';
   let radius = 0.4 * Math.min(props.w, props.h);

src/string.js

@@ -16,3 +16,27 @@ export function trimSpecialCharacters(
 ) {
   return str.replace(pattern, '$1$2');
 }
+
+/**
+ * Determines the label given a rule, a value, an existing label and an override.
+ *
+ * @param {string} rule The rule to match.
+ * @param {string} value The value to be used if the rule is mean to use a value.
+ * @param {string} label The label if the rule is meant to use a label.
+ * @param {string} override An override for the label.
+ * @return {string} The label based on the rule.
+ */
+export function getLabel(rule, value, label, override) {
+  label = override || label;
+  switch(rule) {
+    case 'value':
+      return `${value}`;
+    case 'label':
+      return `${label}`;
+    case 'both':
+      return `${value} ${label}`;
+    case 'none':
+    default:
+      return ``;
+  }
+}

src/string.test.js

@@ -1,4 +1,4 @@
-import {trimSpecialCharacters} from './string';
+import {getLabel, trimSpecialCharacters} from './string';
 
 describe('trimSpecialCharacters', () => {
   test('should trim leading special characters', () => {
@@ -14,3 +14,25 @@ describe('trimSpecialCharacters', () => {
     expect(trimSpecialCharacters('')).toBe('');
   });
 });
+
+describe('getLabel', () => {
+  test('should return the label if the rule specifies so', () => {
+    expect(getLabel('label', 'foo', 'labelle', '')).toEqual('labelle');
+  });
+  test('should return the label override if the rule specifies so and one has been provided', () => {
+    expect(getLabel('label', 'foo', 'labelle', null)).toEqual('labelle');
+    expect(getLabel('label', 'foo', 'labelle', undefined)).toEqual('labelle');
+    expect(getLabel('label', 'foo', 'labelle', '')).toEqual('labelle');
+    expect(getLabel('label', 'foo', 'labelle', 'foobar')).toEqual('foobar');
+  });
+  test('should return the value if the rule specifies so', () => {
+    expect(getLabel('value', 'foo', 'labelle', '')).toEqual('foo');
+  });
+  test('should return the both value and label if the rule specifies so', () => {
+    expect(getLabel('both', 'foo', 'labelle', '')).toEqual('foo labelle');
+  });
+  test('should return empty string otherwise', () => {
+    expect(getLabel('none', 'foo', 'labelle', '')).toEqual('');
+    expect(getLabel('', 'foo', 'labelle', '')).toEqual('');
+  });
+});