Convert Unicode Escapes to Readable Text Convert Unicode escape sequences (\uXXXX) back to readable text.

The unicodeUnescape function employs a two-step replacement process to convert Unicode escape sequences into human-readable characters. It first targets the extended syntax \u{XXXXX} using a regex pattern that captures one or more hexadecimal digits within curly braces, then utilizes String.fromCodePoint() in conjunction with parseInt(hex, 16) to obtain the corresponding code point. This approach allows it to correctly handle Unicode characters that require multiple code units, such as those represented by surrogate pairs.

In the second step, it uses another regex pattern to match the standard \uXXXX syntax, capturing exactly four hexadecimal digits and using String.fromCharCode() in conjunction with parseInt(hex, 16) to produce the desired character. The use of React's useCallback hook ensures that this function is only recreated when necessary, optimizing performance by minimizing unnecessary re-renders. During execution, if an invalid Unicode escape sequence is encountered, it catches the error and returns a specific error message indicating the presence of an invalid sequence.

The tool processes input client-side using TypeScript, compiled to JavaScript for browser execution, which enables it to operate without server requests or exposing sensitive data. This client-side processing relies on the TextToolLayout component from the React library, allowing for efficient handling of user input and output within a structured interface. By preserving non-matching text as-is, the tool maintains the original formatting of the input string, facilitating easier identification and correction of issues in code or configuration files that contain Unicode escape sequences.