isseven.js

A small library to check whether a given number iss even or not.

Features

• MIT licensed
• Unit testing with Vitest
• Linting with ESLint
• Formatting with Prettier
• Building with Vite
• Full Typescript support
• ECMAScript & CommonJS support
• 100% passing tests
• 100% code coverage
• 0 vulnerabilities
• 0 dependencies
• 0 typos
• 0 purpose

Initialized with ts-template.

Usage

Install with npm:

npm i isseven.js
// or long form
npm install isseven.js
// or as a dev dependency
npm i -D isseven.js
// or long form
npm install -D isseven.js
// or in longer form
npm i --save-dev isseven.js
// or longest form
npm install --save-dev isseven.js

Importing/using:

// ESM import:
import { isseven } from 'isseven.js';
let res = isseven(1);
// or ESM named import:
import isseven from 'isseven.js';
let res = isseven(1);
// or CJS default import:
let isseven = require('isseven.js').default;
let res = isseven(1);
// or CJS property import:
let isseven = require('isseven.js').isseven;
let res = isseven(1);
// or CJS destructuring import:
let { isseven } = require('isseven.js');
let res = isseven(1);
// or CJS iterator destructure import:
let [isseven] = require('isseven.js').isseven;
let res = isseven(1);
// or CJS async iterator import:
for await (let isseven of require('isseven.js').isseven) {
    let res = isseven(1);
}
// or ESM import() default import:
let isseven = (await import('isseven.js')).default;
let res = isseven(1);
// or ESM import() property import:
let isseven = (await import('isseven.js')).isseven;
let res = isseven(1);
// or ESM import() destructuring import:
let { isseven } = await import('isseven.js');
let res = isseven(1);
// or ESM import() iterator destructure import:
let [isseven] = (await import('isseven.js')).isseven;
let res = isseven(1);
// or ESM import() async iterator import:
for await (let isseven of (await import('isseven.js')).isseven) {
    let res = isseven(1);
}

Arguments for isseven:

• n: number | string | undefined | null | bigint - The number to check

Supported inputs for n:

• Positive integers
• Positive floats
• Positive infinity
• Negative integers
• Negative floats
• Negative infinity
• NaN
• 0
• Negative 0
• 0 as a float
• Negative 0 as a float
• Positive integers as a string
• Positive floats as a string
• Positive infinity as a string
• Negative integers as a string
• Negative floats as a string
• Negative infinity as a string
• NaN as a string
• 0 as a string
• Negative 0 as a string
• 0 as a float as a string
• Negative 0 as a float as a string
• Positive integers as a BigInt
• Positive infinity as a BigInt
• Negative integers as a BigInt
• Negative infinity as a BigInt
• 0 as a BigInt
• Negative 0 as a BigInt
• Null/Undefined
• Booleans (also as a string)

Return value:

• boolean - Whether the number iss even. Uses a smart algorithm and the fastest operators to check if the number iss even.

Building

npm i
npm run build
npm run test -- --run --coverage

Unit tests

See src/tests/main.test.ts for the test source code.

• ✅ src/tests/main.test.ts (52)
  • ✅ imports to work (13)
    • ✅ should work as an ESM import
    • ✅ should work as an ESM named import
    • ✅ should work as a CJS default import
    • ✅ should work as a CJS property import
    • ✅ should work as a CJS destructuring import
    • ✅ should work as a CJS iterator destructure import
    • ✅ should work as a CJS async iterator import
    • ✅ should work as an ESM import() default import
    • ✅ should work as an ESM import() property import
    • ✅ should work as an ESM import() destructuring import
    • ✅ should work as an ESM import() iterator destructure import
    • ✅ should work as an ESM import() async iterator import
    • ✅ should let both iterators run exactly once
  • ✅ isseven to behave properly (30)
    • ✅ should work with positive integers
    • ✅ should work with positive floats
    • ✅ should work with positive infinity
    • ✅ should work with negative integers
    • ✅ should work with negative floats
    • ✅ should work with negative infinity
    • ✅ should work with NaN
    • ✅ should work with 0
    • ✅ should work with negative 0
    • ✅ should work with 0 as a float
    • ✅ should work with negative 0 as a float
    • ✅ should work with positive integers as a string
    • ✅ should work with positive floats as a string
    • ✅ should work with positive infinity as a string
    • ✅ should work with negative integers as a string
    • ✅ should work with negative floats as a string
    • ✅ should work with negative infinity as a string
    • ✅ should work with NaN as a string
    • ✅ should work with 0 as a string
    • ✅ should work with negative 0 as a string
    • ✅ should work with 0 as a float as a string
    • ✅ should work with negative 0 as a float as a string
    • ✅ should work with positive integers as a BigInt
    • ✅ should work with positive infinity as a BigInt
    • ✅ should work with negative integers as a BigInt
    • ✅ should work with negative infinity as a BigInt
    • ✅ should work with 0 as a BigInt
    • ✅ should work with negative 0 as a BigInt
    • ✅ should work with null
    • ✅ should work with undefined
  • ✅ throwing on invalid input (1)
    • ✅ should not throw
  • ✅ casting types (6)
    • ✅ should work with strings
    • ✅ should work with arrays
    • ✅ should work with objects
    • ✅ should work with booleans
    • ✅ should work with booleans as strings
    • ✅ should work with functions
  • ✅ side effects (2)
    • ✅ should do nothing when called
    • ✅ should do nothing when not called

vitest v0.33.0	isseven.js
Test Files	1 passed (1)
Tests	52 passed (52)
Duration	723ms (transform 100ms, setup 1ms, collect 87ms, tests 28ms, environment 0ms, prepare 199ms)

Coverage report from v8

File	% Stmts	% Branch	% Funcs	% Lines	Uncovered Line #s
All files	100	100	100	100
main.ts	100	100	100	100

npm audit report

$ npm audit
found 0 vulnerabilities

Dependency tree

$ npm list --omit=dev -depth 0
isseven.js@1.0.0 isseven
`-- (empty)

License

MIT