npmpackage.info

Gathering detailed insights and metrics for nth-check

Other packages similar to nth-check

primelist

1.0.0

Fast prime lookup using precomputed data for rapid prime checks and nth prime retrieval.

Gathering detailed insights and metrics for nth-check

nth-check - 2.1.1 | npmpackage.info

nth-check

Parses and compiles CSS nth-checks to highly optimized functions.

2.1.1

BSD-2-Clause

TypeScript

41.56 kB

6.1

Installations

npm install nth-check

Developer Guide

BETA

Typescript

Yes

Module System

CommonJS, ESM

Node Version

18.2.0

NPM Version

8.9.0 Pull Requests

Open

4

Total

961

Closed

101

Merged

856

Issues

Open

1

Total

13

Closed

12

Releases

v2.1.1

Updated on May 23, 2022

v2.1.0

Updated on May 22, 2022

v2.0.1

Updated on Sep 16, 2021

v2.0.0

Updated on Dec 01, 2020

View All 4 releases

Languages

TypeScript

TypeScript (100%)

Developer

fb55

Download Statistics

Total Downloads

Last Day

Last Week

Last Month

Last Year

GitHub Statistics

BSD-2-Clause License

58 Stars

887 Commits

31 Forks

2 Watchers

5 Branches

6 Contributors

Updated on Jul 08, 2025

Sponsor this package

https://github.com/fb55/nth-check?sponsor=1

Maintainers

View All 6 Contributors

Package Meta Information

Latest Version

2.1.1

Package Id

nth-check@2.1.1

Unpacked Size

41.56 kB

Size

8.38 kB

File Count

NPM Version

8.9.0

Node Version

18.2.0

Total Downloads

Cumulative downloads

Total Downloads

NaN

Last Day

NaN

Compared to previous day

Last Week

NaN

Compared to previous week

Last Month

NaN

Compared to previous month

Last Year

NaN

Compared to previous year

Weekly Downloads

Monthly Downloads

Yearly Downloads

Dependencies

boolbase

Dev Dependencies

@types/boolbase @types/jest @types/node @typescript-eslint/eslint-plugin @typescript-eslint/parser eslint eslint-config-prettier jest prettier ts-jest typescript

nth-check

Parses and compiles CSS nth-checks to highly optimized functions.

About

This module can be used to parse & compile nth-checks, as they are found in CSS 3's nth-child() and nth-last-of-type(). It can be used to check if a given index matches a given nth-rule, or to generate a sequence of indices matching a given nth-rule.

nth-check focusses on speed, providing optimized functions for different kinds of nth-child formulas, while still following the spec.

API

1import nthCheck, { parse, compile } from "nth-check";

`nthCheck(formula)`

Parses and compiles a formula to a highly optimized function. Combination of parse and compile.

If the formula doesn't match any elements, it returns boolbase's falseFunc. Otherwise, a function accepting an index is returned, which returns whether or not the passed index matches the formula.

Note: The nth-rule starts counting at 1, the returned function at 0.

Example:

1const check = nthCheck("2n+3");
2
3check(0); // `false`
4check(1); // `false`
5check(2); // `true`
6check(3); // `false`
7check(4); // `true`
8check(5); // `false`
9check(6); // `true`

`parse(formula)`

Parses the expression, throws an Error if it fails. Otherwise, returns an array containing the integer step size and the integer offset of the nth rule.

Example:

1parse("2n+3"); // [2, 3]

`compile([a, b])`

Takes an array with two elements (as returned by .parse) and returns a highly optimized function.

Example:

1const check = compile([2, 3]);
2
3check(0); // `false`
4check(1); // `false`
5check(2); // `true`
6check(3); // `false`
7check(4); // `true`
8check(5); // `false`
9check(6); // `true`

`generate([a, b])`

Returns a function that produces a monotonously increasing sequence of indices.

If the sequence has an end, the returned function will return null after the last index in the sequence.

Example: An always increasing sequence

1const gen = nthCheck.generate([2, 3]);
2
3gen(); // `1`
4gen(); // `3`
5gen(); // `5`
6gen(); // `8`
7gen(); // `11`

Example: With an end value

1const gen = nthCheck.generate([-2, 5]);
2
3gen(); // 0
4gen(); // 2
5gen(); // 4
6gen(); // null

`sequence(formula)`

Parses and compiles a formula to a generator that produces a sequence of indices. Combination of parse and generate.

Example: An always increasing sequence

1const gen = nthCheck.sequence("2n+3");
2
3gen(); // `1`
4gen(); // `3`
5gen(); // `5`
6gen(); // `8`
7gen(); // `11`

Example: With an end value

1const gen = nthCheck.sequence("-2n+5");
2
3gen(); // 0
4gen(); // 2
5gen(); // 4
6gen(); // null

License: BSD-2-Clause

Security contact information

To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.

`nth-check` for enterprise

Available as part of the Tidelift Subscription

The maintainers of nth-check and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. Learn more.

High

7.5/10

Summary

Inefficient Regular Expression Complexity in nth-check

Affected Versions

< 2.0.1

Patched Versions

2.0.1

10

Maintained

Determines if the project is "actively maintained".

10

Binary-Artifacts

Determines if the project has generated executable (binary) artifacts in the source repository.

10

Dangerous-Workflow

Determines if the project's GitHub Action workflows avoid dangerous patterns.

10

License

Determines if the project has defined a license.

10

SAST

Determines if the project uses static code analysis.

7

Vulnerabilities

Determines if the project has open, known unfixed vulnerabilities.

4

Pinned-Dependencies

Determines if the project has declared and pinned the dependencies of its build process.

Reason

dependency not pinned by hash detected -- score normalized to 4

Details

Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/codeql-analysis.yml:23: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/codeql-analysis.yml/master?enable=pin
Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/codeql-analysis.yml:26: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/codeql-analysis.yml/master?enable=pin
Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/codeql-analysis.yml:31: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/codeql-analysis.yml/master?enable=pin
Warn: third-party GitHubAction not pinned by hash: .github/workflows/dependabot-automerge.yml:16: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/dependabot-automerge.yml/master?enable=pin
Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/nodejs-test.yml:21: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/nodejs-test.yml/master?enable=pin
Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/nodejs-test.yml:22: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/nodejs-test.yml/master?enable=pin
Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/nodejs-test.yml:46: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/nodejs-test.yml/master?enable=pin
Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/nodejs-test.yml:48: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/nodejs-test.yml/master?enable=pin
Warn: third-party GitHubAction not pinned by hash: .github/workflows/nodejs-test.yml:64: update your workflow using https://app.stepsecurity.io/secureworkflow/fb55/nth-check/nodejs-test.yml/master?enable=pin
Info: 0 out of 7 GitHub-owned GitHubAction dependencies pinned
Info: 0 out of 2 third-party GitHubAction dependencies pinned
Info: 2 out of 2 npmCommand dependencies pinned

0

Token-Permissions

Determines if the project's workflows follow the principle of least privilege.

0

CII-Best-Practices

Determines if the project has an OpenSSF (formerly CII) Best Practices Badge.

0

Security-Policy

Determines if the project has published a security policy.

0

Fuzzing

Determines if the project uses fuzzing.

Score

6.1

/10

Last Scanned on 2025-07-07

The Open Source Security Foundation is a cross-industry collaboration to improve the security of open source software (OSS). The Scorecard provides security health metrics for open source projects.

Learn More

Other packages similar to nth-check

Other packages similar to nth-check

nth-check

Installations

Developer Guide

Yes

CommonJS, ESM

18.2.0

8.9.0

Pull Requests

4

961

101

856

Issues

1

13

12

Releases

Languages

Developer

fb55

Download Statistics

GitHub Statistics

Sponsor this package

Maintainers

Package Meta Information

Total Downloads

NaN

Weekly Downloads

Monthly Downloads

Yearly Downloads

Dependencies

Dev Dependencies

nth-check

About

API

nthCheck(formula)

parse(formula)

compile([a, b])

generate([a, b])

sequence(formula)

Security contact information

nth-check for enterprise

10

10

10

10

10

7

4

0

0

0

0

6.1

/10

`nthCheck(formula)`

`parse(formula)`

`compile([a, b])`

`generate([a, b])`

`sequence(formula)`

`nth-check` for enterprise