🎀 new package: @does/percent

Author: omrilotan

packages/percent/.gitattributes

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+* text eol=lf

packages/percent/.npmignore

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+.*
+*.log
+spec.js

packages/percent/.npmrc

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+package-lock=false
+access=public

packages/percent/README.md

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+# percent [![](https://img.shields.io/npm/v/@does/percent.svg)](https://www.npmjs.com/package/@does/percent) [![](https://img.shields.io/badge/source--000000.svg?logo=github&style=social)](https://github.com/omrilotan/mono/tree/master/packages/percent)
+
+## A round percentage of a number from the whole
+
+```
+const percent = require('@does/percent');
+
+// percent(part, whole):
+
+percent(150, 200) // 75
+percent(200, 150) // 133
+```

packages/percent/index.js

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+/**
+ * Calculate one part's percentage of the whole
+ * @param  {Number} part
+ * @param  {Number} whole
+ * @return {Number}
+ */
+module.exports = (part, whole) => {
+	if (part === 0 || whole === 0) {
+		return part === whole ? 0 : part > whole ? 100 : 0;
+	}
+
+	return Math.round((part / whole) * 100);
+};

packages/percent/package.json

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+{
+  "name": "@does/percent",
+  "version": "0.0.0",
+  "description": "Calculate one part's percentage of the whole",
+  "keywords": [
+    "percent",
+    "percentage",
+    "calculate"
+  ],
+  "author": "omrilotan",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/omrilotan/mono.git"
+  },
+  "homepage": "https://omrilotan.com/mono/percent/"
+}

packages/percent/spec.js

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+const percent = require('.');
+
+describe('percent', () => {
+	it('Should calculate the percentage', () => {
+		expect(percent(150, 200)).to.equal(75);
+		expect(percent(250, 200)).to.equal(125);
+	});
+	it('Should return 0 when part is 0', () => {
+		expect(percent(0, 200)).to.equal(0);
+	});
+	it('Should return 1000 when whole is 0', () => {
+		expect(percent(200, 0)).to.equal(100);
+	});
+	it('Should return 0 when both are 0', () => {
+		expect(percent(0, 0)).to.equal(0);
+	});
+	it('Should return a whole number', () => {
+		expect(percent(201, 200)).to.equal(100);
+	});
+	it('Should round correctly', () => {
+		expect(percent(234183, 234194)).to.equal(100);
+	});
+});