Monday, September 21, 2020

Last year we released therobots.txt parser and matcher that we use in our production systems to the open source world. Since then, we've seen people build new tools with it,contribute to the open source library (effectively improving our production systems- thanks!), and release new language versions likegolang andrust, which make it easier for developers to build new tools.

With the intern season ending here at Google, we wanted to highlight two new releases related to robots.txt that were made possible by two interns working on the Search Open Sourcing team,Andreea Dutulescu andIan Dolzhanskii.

Robots.txt Specification Test

First, we are releasing atesting framework for robots.txt parser developers, created by Andreea. The project provides a testing tool that can validate whether a robots.txt parser follows the Robots Exclusion Protocol, or to what extent. Currently there is no official and thorough way to assess the correctness of a parser, so Andreea built a tool that can be used to create robots.txt parsers that are following the protocol.

Java robots.txt parser and matcher

Second, we are releasing an officialJava port of the C++ robots.txt parser, created by Ian. Java is the3rd most popular programming language on GitHub and it's extensively used at Google as well, so no wonder it's been the most requested language port. The parser is a 1-to-1 translation of the C++ parser in terms of functions and behavior, and it's been thoroughly tested for parity against a large corpora of robots.txt rules. Teams are already planning to use the Java robots.txt parser in Google production systems, and we hope that you'll find it useful, too.

As usual, we welcome your contributions to these projects. If you built something with theC++ robots.txt parser or with these new releases, let us know so we can potentially help you spread the word! If you found a bug, help us fix it by opening an issue on GitHub or directly contributing with a pull request. If you have questions or comments about these projects, catch us onTwitter!

It was our genuine pleasure to host Andreea and Ian, and we're sad that their internship is ending. Their contributions help make the Internet a better place and we hope that we can welcome them back to Google in the future.

Posted byEdu Pereda andGary Illyes, Google Search Open Sourcing team