CSC/ECE 517 Fall 2015/oss M1504 JJD

M1504: Implement support for missing XMLHttpRequest APIs
XMLHttpRequest is one of the implemented API specifications of Servo that relies upon JavaScript and is used for making dynamic HTTP requests. The goal of the project was to implement support for less common but missing features of the XMLHttpRequest API for Servo.<ref>https://github.com/servo/servo/wiki/Implement-support-for-missing-XMLHttpRequest-APIs</ref>

Introduction

Servo

Servo <ref> https://github.com/servo/servo </ref> is a web browser layout engine written in Rust<ref>https://github.com/rust-lang/rust</ref> and is currently being developed by Mozilla Research. The aim of the project is to create a highly parallel environment that allows for many components be handled by fine-grained, isolated tasks.<ref>https://en.wikipedia.org/wiki/Servo_(layout_engine)</ref>

Rust

Rust is a multi-paradigm, compiled programming language that is a good language for creating highly safe systems. Rust and Servo have a symbiotic relationship as the development of servo has influenced the design of the language.

XMLHttpRequest

"XMLHttpRequest is a definition of an API that provides scripted client functionality for transferring data between a client and a server."<ref>https://xhr.spec.whatwg.org/</ref> XMLHttpRequest provides a way for data to be retrieved from a URL without having to retrieve the entire page. It supports protocols other than HTTP and can be used to retrieve any type of data.<ref>https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest</ref>

Implementation

The following steps were followed to meet the project requirements as per this github page.

Step 1

• compile Servo and ensure that it runs on tests/html/about-mozilla.html
• uncomment the overrideMimeType API in XMLHttpRequest.webidl (components/script/dom/webidls/XMLHttpRequest.webidl), and add a stub method that allows Servo to compile again to xmlhttprequest.rs(components/script/dom/xmlhttprequest.rs).
• run the tests via ./mach test-wpt tests/wpt/web-platform-tests/XMLHttpRequest/ and adjust the expectations for any that now pass (tests/wpt/metadata/XMLHttpRequest/)
• add new override_charset and override_mime_type fields to the XMLHttpRequest structure
• implement the overrideMimeType steps described in the xhr specifications
• update any tests that now pass

Pull Request

Here is our pull request. In the link you can see all code snippets changed due to implementing the above steps, as well as integration test progression information.

References

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