Registry / serialization / to-regex-range

to-regex-range

library5.0.1jsnpmunverified

to-regex-range is a utility library that generates a regex-compatible source string for matching numeric ranges. It simplifies the complex task of creating regular expressions for ranges like '1 to 50' or '0001 to 5555', which can quickly become unwieldy to write manually. The current stable version is 5.0.1. While a specific release cadence isn't published, the library maintains a stable API. Key differentiators include its convenience in abstracting complex regex logic, extensive test validation (over 2.78 million assertions), and optimizations that produce smaller, efficient regular expressions by reducing duplicate sequences and utilizing fragment caching. It handles zero-padding and negative numbers, making it robust for various validation or parsing scenarios.

serialization

npm install to-regex-range

github ↗package ↗

INSTALL

IMPORT

SIG · TO-REGEX-RANGE

to-regex-range

serializationjavascriptv5.0.1

Install

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Import

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Disk

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Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

toRegexRange

✓ import toRegexRange from 'to-regex-range';

✗ import { toRegexRange } from 'to-regex-range';

The library primarily uses CommonJS `module.exports = function...`, so it's a default import in ESM contexts. Named import will likely result in `undefined`.

toRegexRange

✓ const toRegexRange = require('to-regex-range');

This is the original and most direct way to import the library in Node.js CommonJS environments, as shown in its documentation.

toRegexRange

✓ import toRegexRange = require('to-regex-range');

For TypeScript projects configured with CommonJS module resolution or needing explicit CJS import syntax for older libraries.

Demonstrates generating a regex string for a numeric range, creating a RegExp object, and testing various numbers. Also shows how to use options like `relaxZeros` for specific padding requirements.

import toRegexRange from 'to-regex-range'; // Generate a regex source string for numbers 1 to 100 const rangeSource = toRegexRange(1, 100); console.log(`Generated regex source: ${rangeSource}`); // Expected output: Generated regex source: [1-9]|[1-9][0-9]|100 // Create a RegExp object from the source, adding start/end anchors const regex = new RegExp(`^${rangeSource}$`); console.log(`Testing '5': ${regex.test('5')}`); // true console.log(`Testing '50': ${regex.test('50')}`); // true console.log(`Testing '100': ${regex.test('100')}`); // true console.log(`Testing '0': ${regex.test('0')}`); // false console.log(`Testing '101': ${regex.test('101')}`); // false console.log(`Testing '05' (zero-padded, not matched by default): ${regex.test('05')}`); // false // Example with zero-padding option for 001 to 010 const zeroPaddedSource = toRegexRange('001', '010', { relaxZeros: false }); const zeroPaddedRegex = new RegExp(`^${zeroPaddedSource}$`); console.log(`\nGenerated zero-padded regex source: ${zeroPaddedSource}`); console.log(`Testing '005': ${zeroPaddedRegex.test('005')}`); // true console.log(`Testing '010': ${zeroPaddedRegex.test('010')}`); // true

Debug

Known issues

gotchaThe `toRegexRange` function returns a regular expression *source string*, not a `RegExp` object. Developers must pass this string to `new RegExp()` themselves to create a usable regular expression.

fix

Always wrap the output in `new RegExp()`: `const regex = new RegExp(toRegexRange(min, max));`

affects: >=1.0.0

gotchaWhen using the generated regex, it's often crucial to add `^` (start of string) and `$` (end of string) anchors to ensure the regex matches the entire input string, rather than just a substring. Without anchors, `new RegExp(toRegexRange('1', '5')).test('030')` would return `true` because '3' is in the range.

fix

Apply anchors to the generated source: `const regex = new RegExp(`^${toRegexRange(min, max)}$`);`

affects: >=1.0.0

gotchaBy default, `to-regex-range` relaxes matching for leading zeros when ranges are zero-padded (e.g., `toRegexRange('-0010', '0010')`). If strict zero-padding is required, the `relaxZeros: false` option must be used.

fix

For strict zero-padding, pass `{ relaxZeros: false }` in the options object: `toRegexRange('001', '010', { relaxZeros: false });`

affects: >=2.0.0

gotchaThe library does not support 'steps' or 'increments' for ranges (e.g., matching only even numbers within a range). It generates a regex for every number within the min/max boundary.

fix

For stepped ranges, additional filtering or a different approach is needed after matching the broad range, or a custom regex must be constructed manually.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: toRegexRange is not a function

Attempting a named import in an ESM module when the library exports a default function (CommonJS `module.exports`).

fix

Use a default import: `import toRegexRange from 'to-regex-range';` or CommonJS `const toRegexRange = require('to-regex-range');`

Regex unexpectedly matches substrings, not entire numbers.

Forgetting to apply `^` and `$` anchors to the generated regex string before creating the `RegExp` object.

fix

Ensure the generated source is wrapped with anchors: `const regex = new RegExp(`^${toRegexRange(min, max)}$`);`

Regex does not match zero-padded numbers when expected, or matches non-zero-padded numbers when strict padding is desired.

Incorrect use or understanding of the `relaxZeros` option, which defaults to `true` to allow flexible zero-padding matching.

fix

Adjust the `relaxZeros` option in the options object, typically setting `relaxZeros: false` for strict zero-padding: `toRegexRange('001', '010', { relaxZeros: false });`

Upgrade

Version history

5.0.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

5 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/micromatch/to-regex-range ↗

packagehttps://www.npmjs.com/package/to-regex-range ↗