feat: add next-code-point-index string package

[steff456]

Part of #1062

Description

What is the purpose of this pull request?

This pull request:

• Adds @stdlib/string/next-code-point-index

Related Issues

Does this pull request have any related issues?

This pull request:

Part of #1062

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

This PR depends on the package @stdlib/string/num-code-points available in #1097

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

---

@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point	$\color{green}162/162$ $\color{green}+100.00\%$	$\color{green}22/22$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}162/162$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point	$\color{green}162/162$ $\color{green}+100.00\%$	$\color{green}22/22$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}162/162$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{green}161/161$ $\color{green}+100.00\%$	$\color{green}22/22$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}161/161$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{green}160/160$ $\color{green}+100.00\%$	$\color{green}22/22$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}160/160$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{green}159/159$ $\color{green}+100.00\%$	$\color{green}22/22$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}159/159$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{green}154/154$ $\color{green}+100.00\%$	$\color{green}22/22$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}154/154$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[kgryte]

@steff456 Thanks for working on this. There are a few discrepancies among return values. And I left a question regarding what should happen for unpaired surrogates.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{green}154/154$ $\color{green}+100.00\%$	$\color{green}22/22$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}154/154$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{green}157/157$ $\color{green}+100.00\%$	$\color{green}25/25$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}157/157$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{green}157/157$ $\color{green}+100.00\%$	$\color{green}26/26$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}157/157$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[kgryte]

Suggested change

	out = nextCodePointIndex( '𐒻𐓟𐒻𐓟', 1 );
	t.strictEqual( out, 3, 'returns expected value' );
	out = nextCodePointIndex( '𐒻𐓟𐒻𐓟', 0 );
	t.strictEqual( out, 2, 'returns expected value' );

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/next-code-point-index	$\color{red}149/151$ $\color{green}+98.68\%$	$\color{red}19/20$ $\color{green}+95.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{red}149/151$ $\color{green}+98.68\%$

The above coverage report was generated for the changes in this PR.

[kgryte]

LGTM.