feat: Add Length Conversion (TheAlgorithms#1390)

Author: 0APOCALYPSE0

Conversions/LengthConversion.js

@@ -0,0 +1,38 @@
+/**
+ * Converts a length from one unit to another.
+ *
+ * @param {number} length - The length to convert.
+ * @param {string} fromUnit - The unit to convert from (e.g., "km", "m", "cm").
+ * @param {string} toUnit - The unit to convert to (e.g., "km", "m", "cm").
+ * @returns {number} The converted length.
+ * @throws {Error} If the units are invalid or not found in the conversion dictionary.
+ */
+
+const lengthConversion = (length, fromUnit, toUnit) => {
+  // Define a dictionary to map units to meters
+  const meters = {
+    mm: 0.001,
+    cm: 0.01,
+    m: 1,
+    km: 1000,
+    inch: 0.0254,
+    ft: 0.3048,
+    yd: 0.9144,
+    mi: 1609.34
+  }
+
+  // Check if the units are in the dictionary, otherwise, throw an error
+  if (!(fromUnit in meters) || !(toUnit in meters)) {
+    throw new Error('Invalid units')
+  }
+
+  // Perform the conversion
+  const metersFrom = length * meters[fromUnit]
+  const convertedLength = metersFrom / meters[toUnit]
+
+  return convertedLength
+}
+
+export {
+  lengthConversion
+}

Conversions/test/LengthConversion.test.js

@@ -0,0 +1,53 @@
+import { lengthConversion } from '../LengthConversion.js'
+
+describe('LengthConversion', () => {
+  it.each`
+    length | fromUnit | toUnit   | expected
+    ${10}  | ${'km'}  | ${'m'}   | ${10000}
+    ${100} | ${'m'}   | ${'km'}  | ${0.1}
+    ${5}   | ${'cm'}  | ${'mm'}  | ${50}
+    ${12}  | ${'ft'}  | ${'inch'}| ${144.00000000000003}
+  `(
+    'converts $length $fromUnit to $toUnit',
+    ({ length, fromUnit, toUnit, expected }) => {
+      try {
+        const result = lengthConversion(length, fromUnit, toUnit)
+        expect(result).toBe(expected)
+      } catch (error) {
+        expect(error).toBeUndefined()
+      }
+    }
+  )
+
+  it.each`
+    length | fromUnit | toUnit   | expected
+    ${10}  | ${'m'}   | ${'km'}  | ${0.01}
+    ${1000}| ${'mm'}  | ${'cm'}  | ${100}
+    ${1}   | ${'inch'}| ${'ft'}  | ${0.08333333333}
+  `(
+    'converts $length $fromUnit to $toUnit (vice versa)',
+    ({ length, fromUnit, toUnit, expected }) => {
+      try {
+        const result = lengthConversion(length, fromUnit, toUnit)
+        expect(result).toBeCloseTo(expected, 10) // Close comparison due to floating-point precision
+      } catch (error) {
+        expect(error).toBeUndefined()
+      }
+    }
+  )
+
+  it.each`
+    length | fromUnit | toUnit     | expectedError
+    ${10}  | ${'km'}  | ${'invalid'} | ${'Invalid units'}
+    ${5}   | ${'invalid'} | ${'m'}    | ${'Invalid units'}
+  `(
+    'returns error message for invalid units: $fromUnit to $toUnit',
+    ({ length, fromUnit, toUnit, expectedError }) => {
+      try {
+        lengthConversion(length, fromUnit, toUnit)
+      } catch (error) {
+        expect(error.message).toBe(expectedError)
+      }
+    }
+  )
+})