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9ba4920
Prepare 3rd blog post for summer of code summary posts (2025)
ktoso Nov 4, 2025
e91be3f
Merge branch 'main' into gsoc-2025-post-3-lsp-documentation
ktoso Nov 4, 2025
4932cee
Update _posts/2025-11-NN-swift-gsoc-2025-highlight-3-vscode-swift-lsp…
ktoso Nov 5, 2025
4dfba61
Update _posts/2025-11-NN-swift-gsoc-2025-highlight-3-vscode-swift-lsp…
ktoso Nov 5, 2025
6198c6b
Move post to Developer Tools category
ktoso Nov 5, 2025
b212f41
Apply suggestions from code review
ktoso Nov 5, 2025
a1d2dc6
Merge branch 'main' into gsoc-2025-post-3-lsp-documentation
ktoso Nov 6, 2025
dd65345
rename file and move the link to full version
ktoso Nov 6, 2025
88cf42e
Surround author with quotes
ktoso Nov 6, 2025
1dc4223
Update _posts/2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp…
davelester Nov 10, 2025
2629cbe
Update _data/authors.yml
davelester Nov 10, 2025
199a105
Update 2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp-docume…
ktoso Nov 11, 2025
524663c
Update 2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp-docume…
ktoso Nov 11, 2025
749537e
Update 2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp-docume…
ktoso Nov 11, 2025
96e71dd
Update 2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp-docume…
ktoso Nov 11, 2025
8ca01b2
Update 2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp-docume…
ktoso Nov 11, 2025
b3ecc39
Update 2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp-docume…
ktoso Nov 11, 2025
7a4e3b6
Update 2025-11-12-swift-gsoc-2025-highlight-3-vscode-swift-lsp-docume…
ktoso Nov 11, 2025
db683f8
add instructions on how to try it out
ktoso Nov 11, 2025
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6 changes: 6 additions & 0 deletions _data/authors.yml
Original file line number Diff line number Diff line change
Expand Up @@ -560,6 +560,12 @@ mitchellallison:
github: mitchellallison
about: "Mitchell Allison works on Distributed Systems in Swift at Apple."

ahmedelrefaey:
name: Ahmed Elrefaey
email: a7med.mahmoud2004@gmail.com
github: a7medev
about: "Ahmed is a software developer at Luciq. During Google Summer of Code 2025, he worked on improving the display of Swift documentation during code completion in SourceKit-LSP and VS Code."

priyambada:
name: Priyambada Roul
email: priyaroul99@gmail.com
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@@ -0,0 +1,72 @@
---
layout: new-layouts/post
published: true
date: 2025-11-12 10:00:00
title: "Swift GSoC 2025 highlight: Improved code completion for Swift"
author: [ahmedelrefaey, hamish, ktoso]
category: "Developer Tools"
---

Another successful year of Swift participation in [Google Summer of Code](https://summerofcode.withgoogle.com) recently came to an end, and we'd like to shine some light on the projects and work accomplished!

Summer of Code is an annual program, organized by Google, which provides hands-on experience for newcomers contributing
to open source projects.

In this series of four blog posts, we'll highlight each of the Summer of Code contributors and their projects.
You can navigate between the posts using these convenient links:


- [Bringing Swiftly support to VS Code](/blog/gsoc-2025-showcase-swiftly-support-in-vscode/)
- [Extending Swift-Java Interoperability](/blog/gsoc-2025-showcase-swift-java/)
- Improved code completion for Swift _(this post)_
- Improved console output for Swift Testing _(coming soon)_

Each GSoC contributor has shared a writeup about their project and experience in the program on the forums. The first project we're featuring on the blog brought Swiftly support to Visual Studio Code, contributed by Priyambada Roul.
To learn more, you can read the [full post on the Swift forums](https://forums.swift.org/t/gsoc-2025-bringing-swiftly-support-to-vs-code/81886).

Summer of Code is an annual program, organized by Google, which provides hands-on experience for newcomers contributing
to open source projects. Participants usually are students, but do not have to be.

The third project we're featuring on the Swift blog improved how documentation is displayed by SourceKit-LSP and IDEs which make use of it, such as VS Code, contributed by Ahmed Elrefaey. To learn more, you can read the [full post on the Swift forums](https://forums.swift.org/t/gsoc-2025-improve-the-display-of-documentation-during-code-completion-in-sourcekit-lsp/81976)!


---

## Improve the display of documentation during code completion in SourceKit-LSP

Hi everyone!

This is Ahmed Elrefaey. I’m excited to share with you an update on my GSoC project which improved the display of documentation during code completion for Swift. I worked on improvements to [SourceKit-LSP](https://github.com/swiftlang/sourcekit-lsp), which is an implementation of the [Language Server Protocol](https://microsoft.github.io/language-server-protocol/) (LSP) for Swift and C-based languages. My GSoC project was mentored by Hamish Knight.

### Project Goals

The aim of this project is to enhance how documentation is displayed in SourceKit-LSP during code completion by:

1. Showing the full documentation for a code completion item instead of the first paragraph only, which we call “brief documentation”.
2. Implementing Language Server Protocol’s [signature help](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_signatureHelp) request showing the user which overloads are available, along with their corresponding documentation.

Editors that support the Language Server Protocol all benefit from these improvements to SourceKit-LSP, bringing these features to editors like VS Code, Neovim, IntelliJ IDEA, Vim, and more.
### Progress

During this summer, we have made great progress on this project that I want to share with you.

We have successfully implemented full documentation comment retrieval for completion items by lazily retrieving the full documentation comment upon request to avoid having to fetch all documentation comments at once.

Here’s what SourceKit-LSP currently provides in VS Code (brief documentation):

![Brief documentation demo in VS Code.|690x412](/assets/images/gsoc-25/brief.gif)

And here’s how it looks with full documentation:

![Full documentation demo in VS Code.|690x412](/assets/images/gsoc-25/full.gif)

We have also implemented a large portion of signature help support, showing the available overloads and their corresponding documentation while editing.
We reused the existing argument completion logic to determine the overloads and refactored the code completion item description implementation to reuse it in signature help.

Here’s a quick demo of signature help in VS Code.

![Signature help demo in VS Code.|690x441](/assets/images/gsoc-25/output.gif)
To try this out in VS Code for yourself, you can [download a main development snapshot from swift.org](https://swift.org/download). If using Swiftly you can run `swiftly install main-snapshot`. Then, in VS Code you can pick "Select Toolchain" from the Command Palette and select the newly downloaded toolchain.
### Closing Thoughts

I'm incredibly grateful for this opportunity to contribute to the Swift project, and I really learned a lot from this experience. I'd like to thank my mentor, Hamish Knight, for his unwavering support and guidance throughout this summer. I’d also like to thank Alex Hoppen, Rintaro Ishizaki, and Ben Barham for their valuable feedback during code review.
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