std/semver/is_semver.ts

// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
import { ANY, INVALID } from "./constants.ts";
import type { SemVer } from "./types.ts";
import { isValidNumber, isValidString } from "./_shared.ts";

/**
 * Checks to see if value is a valid SemVer object. It does a check
 * into each field including prerelease and build.
 *
 * Some invalid SemVer sentinels can still return true such as ANY and INVALID.
 * An object which has the same value as a sentinel but isn't reference equal
 * will still fail.
 *
 * Objects which are valid SemVer objects but have _extra_ fields are still
 * considered SemVer objects and this will return true.
 *
 * A type assertion is added to the value.
 * @param value The value to check to see if its a valid SemVer object
 * @returns True if value is a valid SemVer otherwise false
 */
export function isSemVer(value: unknown): value is SemVer {
  if (value === null || value === undefined) return false;
  if (Array.isArray(value)) return false;
  if (typeof value !== "object") return false;
  if (value === INVALID) return true;
  if (value === ANY) return true;

  const {
    major,
    minor,
    patch,
    build = [],
    prerelease = [],
  } = value as Record<string, unknown>;
  return (
    isValidNumber(major) &&
    isValidNumber(minor) &&
    isValidNumber(patch) &&
    Array.isArray(prerelease) &&
    prerelease.every((v) => isValidString(v) || isValidNumber(v)) &&
    Array.isArray(build) &&
    build.every(isValidString)
  );
}