Expect, a core component of the Jest testing framework, provides a robust and versatile assertion library for JavaScript. Version 24.4.0 refines the previous stable release, 24.3.1, offering subtle yet impactful improvements. Both versions export the foundational expect function, essential for writing clear and concise tests, thoroughly documented on Jest's website.
The primary difference lies in the dependency on jest-matcher-utils. Version 24.4.0 updates this dependency to version 24.4.0, while 24.3.1 relies on version 24.3.1. This seemingly small version bump in jest-matcher-utils likely contains enhancements, bug fixes, or performance improvements within Jest's internal matcher utilities. While the direct impact on developers using expect might not be immediately apparent, staying current with this dependency ensures access to the latest refinements in Jest's assertion mechanisms, potentially leading to more reliable and accurate test results.
Both versions share identical dependencies on @jest/types, ansi-styles, jest-get-type, jest-regex-util, and jest-message-util. They also share the same development dependency, @types/ansi-styles, license, and repository information. The unpacked size of version 24.4.0 is marginally larger, suggesting additions to the codebase and the release date shifted 4 days after. Developers leveraging Expect directly or indirectly through Jest benefit from the consistent API and feature set across these versions, with 24.4.0 offering the latest under-the-hood refinements for enhanced testing capabilities.
All the vulnerabilities related to the version 24.4.0 of the package
Regular Expression Denial of Service (ReDoS) in micromatch
The NPM package micromatch prior to version 4.0.8 is vulnerable to Regular Expression Denial of Service (ReDoS). The vulnerability occurs in micromatch.braces() in index.js because the pattern .* will greedily match anything. By passing a malicious payload, the pattern matching will keep backtracking to the input while it doesn't find the closing bracket. As the input size increases, the consumption time will also increase until it causes the application to hang or slow down. There was a merged fix but further testing shows the issue persisted prior to https://github.com/micromatch/micromatch/pull/266. This issue should be mitigated by using a safe pattern that won't start backtracking the regular expression due to greedy matching.
Uncontrolled resource consumption in braces
The NPM package braces fails to limit the number of characters it can handle, which could lead to Memory Exhaustion. In lib/parse.js, if a malicious user sends "imbalanced braces" as input, the parsing will enter a loop, which will cause the program to start allocating heap memory without freeing it at any moment of the loop. Eventually, the JavaScript heap limit is reached, and the program will crash.
