Expect version 24.7.0 and 24.6.0 are both iterations of the assertion library integral to Jest, designed to make testing JavaScript code more readable and reliable. Both versions export the core expect function, the cornerstone of Jest's assertion capabilities, and are thoroughly documented on the Jest website. Key among similarities, both rely on ansi-styles and @types/ansi-styles for terminal styling and highlighting differences.
However, comparing the dependency declarations highlights the key changes. Version 24.7.0 introduces updates to several internal Jest utilities. Specifically, @jest/types, jest-message-util, and jest-matcher-utils jump from version 24.6.0 to 24.7.0. These suggest improvements and fixes within Jest's internal type definitions, message construction, and matcher utilities, potentially impacting error reporting and overall testing precision. While seemingly minor, these adjustments contribute to a more robust and developer-friendly testing experience. The size of the unpacked package is also slightly decreased on version 24.7.0. Ultimately, version 24.7.0 presents a somewhat updated version of the package with dependency upgrades and a slightly smaller package size that make it a little more appealing to developers.
All the vulnerabilities related to the version 24.7.0 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.
