Expect, a core component of the Jest testing framework, provides the expect function, empowering developers to write expressive and reliable tests. Version 24.3.1 represents a minor update over the previous stable version, 24.3.0, indicating bug fixes or small improvements likely intended to enhance stability and reliability. Both versions share the same fundamental purpose: facilitating assertions in JavaScript tests within the Jest ecosystem. Key dependencies remain consistent, including @jest/types, ansi-styles, jest-get-type, jest-regex-util, and jest-message-util, underscoring the shared core functionality.
The most notable difference surfaces in the jest-matcher-utils dependency. Version 24.3.1 utilizes jest-matcher-utils@24.3.1 compared to version 24.3.0 which makes use of jest-matcher-utils@24.3.0, therefore potentially hinting at refined matcher utilities integrated into the newer version. Developers leveraging Expect directly might observe subtle enhancements related to matcher behavior and messaging. Furthermore, the unpackedSize differs slightly between the two versions. While both boast a file count of 42, version 24.3.1 exhibits 2760276 while version is slighlty lighter at 2732634. This difference, along with the new version of a dependency shows a number of under-the-hood optimizations. These updates are essential for ensuring the stability and accuracy of javascript testing and therefore improve user experiences and performance.
All the vulnerabilities related to the version 24.3.1 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.
