incrementPrerelease

Increments the prerelease portion of a version, according to the given scheme — the semantics npm version prerelease --preid <id> uses, not covered by increment (which only handles 'major' | 'minor' | 'patch').

'semver' (default):

• No current prerelease (a release version) → bumps patch and starts a new prerelease line at <prereleaseId>.0 (a prerelease of the version itself, e.g. 1.2.3, would already be released).
• Same prerelease type as the current version → increments its counter.
• Different prerelease type (e.g. alpha → beta) → resets the counter to 0.

Input prerelease can be any shape, but only the first two parts are considered; output is always normalized to <prereleaseId>.<number>. Build metadata, if any, is dropped — it’s tied to the specific build that produced the input version, not the new one. A leading v is preserved if present, matching increment’s behavior (parse/ stringify alone would strip it — see their docs).

'gentoo' — the same rules, but prereleaseId must be one of the five real Gentoo suffix types (alpha/beta/pre/rc/p), not a free-form string — Portage’s suffix vocabulary is fixed by spec, unlike SemVer’s arbitrary prerelease identifiers. No current prerelease suffix bumps the last numeric component instead of specifically patch, since Gentoo’s components array can be any length.

'debian' — throws: a Debian upstream version is free-form, with no prerelease counter to bump.

Available since v3.0.1

Import

import { incrementPrerelease } from '@helpers4/version';
// or, from the all-in-one package (same code, one install):
import { incrementPrerelease } from 'helpers4/version';

Signature

incrementPrerelease(version: string, prereleaseId: string, scheme?: VersionScheme): string

Parameters

Parameter	Type	Description
version	string	The version to increment
prereleaseId	string	The prerelease type/identifier (e.g. `‘alpha’`, `‘beta’`, `‘rc’`)
scheme	VersionScheme	Which version scheme to interpret `version` as. Defaults to `‘semver’`. (optional)

Returns

string — The version with an incremented or newly-started prerelease

Examples

Start a new alpha line

Bumping a release version starts a fresh prerelease at .0, one patch ahead.

incrementPrerelease('1.2.3', 'alpha')
// => '1.2.4-alpha.0'

Increment the same prerelease type

Bumping with the same prereleaseId increments its counter.

incrementPrerelease('1.2.4-alpha.0', 'alpha')
// => '1.2.4-alpha.1'

Switch prerelease type

Switching to a different prereleaseId resets the counter to 0, e.g. graduating from alpha to beta.

incrementPrerelease('1.2.4-alpha.3', 'beta')
// => '1.2.4-beta.0'

Increment a Gentoo/Portage prerelease

prereleaseId must be one of Gentoo’s fixed suffix types (alpha/beta/pre/rc/p), not a free-form string.

incrementPrerelease('1.2.3', 'alpha', 'gentoo')
// => '1.2.4_alpha'

Related Types

VersionScheme

Identifies which version scheme parse/compare should use to interpret a version string. Defaults to 'semver' everywhere it’s accepted.

type VersionScheme = 'semver' | 'gentoo' | 'debian'

Source

View source on GitHub