Levn is a JavaScript library that parses short human-entered text into JavaScript values according to an expected type (using type information for casting and validation). It is useful for turning config file values and command line arguments written in a concise notation into correctly typed values, including support for arrays, objects, tuples, dates, and regular expressions.
Project status
- Maintenance status: Evidence suggests the repo is not actively maintained today, with the last listed upstream push on 2023-07-18 and the most recent published updates only shown up to 0.4.1 (2020-04-04).
- Update cadence: The observed update cadence is historically bursty (2013 to 2015 several updates, then 2014 to 2020), and there is a multi-year gap between the latest shown update (2020) and today (2026), indicating no steady release stream.
AI summary generated
Recent updates
0.4.1
Release 0.4.1 is a small update with no release notes provided. The code changes are limited to version metadata, a fix in string unescaping logic for single-quoted literals, and additional test coverage for those cases.
0.4.0
Version 0.4.0 updates Levn’s internals (LiveScript and dependency upgrades) and changes how String values are parsed and cast when the expected type is exactly [String] with explicit mode disabled. No release notes were provided, so the behavioral changes below are effectively undocumented.
Breaking0.3.0
Release 0.3.0 was published on 2015-12-29, but no release notes were provided by the publisher. As a result, there is not enough documented information to identify new features, breaking changes, bug fixes, security updates, or migration steps for developers.
0.2.5
Release 0.2.5 only includes a version bump in the published package metadata and a small but behaviorally significant change in the object casting logic. No release notes were provided, so the notable behavioral differences come entirely from the code diff and test additions.
0.2.4
Release 0.2.4 contains no publisher-provided release notes. The code changes focus on the internal string parsing logic and dependency bumps, with accompanying test updates that indicate altered parsing behavior for previously failing inputs.
Features0.2.3
Release 0.2.3 is a small update that bumps the package version string across the JS and LiveScript sources and README. The only functional code change adjusts how escaped single quotes are escaped when parsing implicit string values.
0.2.2
Release 0.2.2 appears to be a small update with no published release notes. The code changes focus on how Levn tokenizes and unescapes string literals and how it parses regular expression literals and their flags, plus some metadata and build/test adjustments.
Breaking0.2.1
Release 0.2.1 contains a small set of parsing-related code changes focused on how string, date, and regexp literals are recognized. The provided release notes contain no listed changes, so the behavioral impact must be inferred from the code diff. The largest change is in string parsing when the expected type is exactly String, where inputs are now wrapped/escaped differently.
0.2.0
Release 0.2.0 (2013-10-29) contains changes to the parsing and casting logic, including updated tokenization and special handling for expected String types. There are no published release notes for this version, so behavior changes must be inferred from the code diff and updated tests.
BreakingFeatures0.1.0
Release 0.1.0 was published on 2013-10-03, but no release notes were provided by the publisher. Because the release notes are missing, there is no documented information about new features, bug fixes, security updates, or breaking changes to evaluate for upgrade impact.