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Version

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Overview

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Files

docs

comparison.md index.md ranges.md validation.md

tile.json

Version Validation

Validation functions for ensuring version strings conform to semver standards, with both permissive and strict validation modes.

Capabilities

validate Function

Permissive validation that accepts various version formats including wildcards and flexible patterns.

/**
 * Validate semver version strings.
 * @param version Version number to validate
 * @returns `true` if the version number is a valid semver version number, `false` otherwise.
 */
function validate(version: string): boolean;

Usage Examples:

import { validate } from "compare-versions";

// Standard semver versions
validate('1.0.0');              // true
validate('1.0.0-alpha.1');      // true
validate('1.0.0+build.123');    // true
validate('1.0.0-beta+exp.sha');  // true

// Flexible formats (accepted by permissive validate)
validate('1.0');                // true
validate('1');                  // true
validate('v1.0.0');             // true
validate('1.01.1');             // true (leading zeros)

// Wildcards and special patterns
validate('1.0.x');              // true
validate('1.0.*');              // true
validate('1.x.x');              // true

// Chromium-style 4-part versions
validate('25.0.1364.126');      // true

// Invalid versions
validate('foo');                // false
validate('1.0.0.0.0');          // false
validate('');                   // false
validate('1.0-rc.1');           // false (missing patch)

validateStrict Function

Strict validation that only accepts properly formatted semver versions according to semver.org specification.

/**
 * Validate semver version strings strictly. Will not accept wildcards and version ranges.
 * @param version Version number to validate
 * @returns `true` if the version number is a valid semver version number `false` otherwise
 */
function validateStrict(version: string): boolean;

Usage Examples:

import { validateStrict } from "compare-versions";

// Valid strict semver versions
validateStrict('1.0.0');                    // true
validateStrict('0.0.0');                    // true
validateStrict('1.0.0-alpha');              // true
validateStrict('1.0.0-alpha.1');            // true
validateStrict('1.0.0-0.3.7');              // true
validateStrict('1.0.0+20130313144700');     // true
validateStrict('1.0.0-beta+exp.sha.5114f85'); // true

// Invalid for strict validation (but may be valid for permissive)
validateStrict('1.0');                      // false (missing patch)
validateStrict('1');                        // false (missing minor and patch)
validateStrict('v1.0.0');                   // false (leading v)
validateStrict('1.01.0');                   // false (leading zero)
validateStrict('1.0.x');                    // false (wildcard)
validateStrict('1.0.*');                    // false (wildcard)

// Always invalid
validateStrict('foo');                      // false
validateStrict('');                         // false
validateStrict('1.0.0.0');                  // false (too many parts)

Validation Differences

Permissive vs Strict Comparison

Version String	`validate()`	`validateStrict()`	Notes
`1.0.0`	✅ true	✅ true	Perfect semver
`1.0.0-alpha`	✅ true	✅ true	Pre-release
`1.0.0+build`	✅ true	✅ true	Build metadata
`1.0`	✅ true	❌ false	Missing patch
`1`	✅ true	❌ false	Missing minor & patch
`v1.0.0`	✅ true	❌ false	Leading v
`1.01.0`	✅ true	❌ false	Leading zero
`1.0.x`	✅ true	❌ false	Wildcard
`25.0.1364.126`	✅ true	❌ false	4-part Chromium
`foo`	❌ false	❌ false	Invalid

When to Use Each

Use validate() when:

Processing user input that may be in various formats
Working with version strings from different sources
Need to accept common version variations
Building user-friendly interfaces

Use validateStrict() when:

Enforcing strict semver compliance
Validating versions for publication
Ensuring compatibility with strict semver tools
API validation where precision is required

Input Type Handling

Both validation functions handle type checking:

// Non-string inputs
validate(123);          // false
validate(null);         // false
validate(undefined);    // false
validate({});          // false

validateStrict(123);    // false
validateStrict(null);   // false
validateStrict(undefined); // false
validateStrict([]);     // false

Usage in Workflows

Form Validation

import { validate, validateStrict } from "compare-versions";

function validateVersionInput(version: string, strict: boolean = false) {
  const isValid = strict ? validateStrict(version) : validate(version);
  
  if (!isValid) {
    const message = strict 
      ? "Version must follow strict semver format (e.g., 1.0.0)"
      : "Version format is invalid";
    throw new Error(message);
  }
  
  return version;
}

// Usage
validateVersionInput("1.0.0", true);   // OK
validateVersionInput("1.0", false);    // OK
validateVersionInput("1.0", true);     // Error: Version must follow strict semver format

Pre-processing Pipeline

import { validate, validateStrict } from "compare-versions";

function processVersions(versions: string[]) {
  // Filter to only valid versions
  const validVersions = versions.filter(validate);
  
  // Separate strict vs flexible versions
  const strictVersions = validVersions.filter(validateStrict);
  const flexibleVersions = validVersions.filter(v => !validateStrict(v));
  
  return {
    valid: validVersions,
    strict: strictVersions,
    flexible: flexibleVersions
  };
}

// Usage
const result = processVersions(['1.0.0', '1.0', 'v2.0.0', 'invalid']);
// result.valid: ['1.0.0', '1.0', 'v2.0.0']
// result.strict: ['1.0.0']
// result.flexible: ['1.0', 'v2.0.0']

Regular Expression Details

The validation functions use different internal patterns:

validate(): Uses a permissive regex that accepts various formats and wildcards
validateStrict(): Uses the official semver.org regular expression pattern

Both functions ensure the input is a string and starts with a digit or 'v' before applying regex validation.