# Copilot Published articles for Copilot. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## Microsoft призвала пользователей Copilot Cowork внимательнее подтверждать действия ИИ DevFeed: [Microsoft призвала пользователей Copilot Cowork внимательнее подтверждать действия ИИ]() Original publisher: [Read original article]() Author: maybe\_elf Published: 2026-09-17T09:27:08Z Content type: news Language: ru Sources: [Tagir Valeev]() Topics: [Microsoft]() Tags: [copilot](), [copilot-cowork](), [microsoft](), [microsoft-365](), [tag-557abbaa7401](), [tag-64251c106897](), [tag-6d7842c9e760](), [tag-d96e238f1419](), [tag-e95ee8b94dca](), [tag-f7a9fbf01460]() ### AI overview Microsoft warned Copilot Cowork users that its AI agents can make mistakes, misinterpret instructions, or follow hidden malicious commands. The company emphasized that users remain responsible for actions performed on their behalf and described confirmation prompts that allow users or administrators to approve, pause, or cancel tasks. ### Source excerpt Microsoft недавно представила Copilot Cowork -- инструмент на базе ИИ-агентов, способный автоматизировать множество рабочих процессов, включая разработку приложений. Теперь компания предупредила пользователей о мерах предосторожности при работе с ним. Читать далее ## Improving Test Coverage in the Interview Coach Application with GitHub Copilot DevFeed: [Improving Test Coverage in the Interview Coach Application with GitHub Copilot]() Original publisher: [Read original article]() Author: Aaron Powell Published: 2026-09-15T16:00:21Z Content type: tutorial Language: en Sources: [Visual Studio Blog]() Topics: [test-coverage](), [Test coverage](), [GitHub Copilot](), [App](), [Visual Studio](), [Code]() Tags: [agent](), [analysis](), [code-coverage](), [copilot](), [github-copilot](), [productivity](), [projects](), [run](), [test](), [test-coverage](), [testing](), [tests](), [unit-tests](), [visual-studio]() ### AI overview This tutorial explains how to improve test coverage in the Interview Coach application by establishing a baseline, using GitHub Copilot's Test Agent to generate unit tests, and analyzing coverage across the solution. The article reports coverage increasing from 37% to 81%. ### Source excerpt Today I want to look at how we can improve on the test coverage that we have in the Interview Coach application. This application has some unit tests in it already, but I'm sure there is room for improvement. Defining our baseline Before we start writing tests, it's a good idea to have a baseline [...] The post Today I will... improve test coverage appeared first on Visual Studio Blog. ## Switching from Microsoft 365 to Google is unlikely to deliver significant savings, Gartner says DevFeed: [Switching from Microsoft 365 to Google is unlikely to deliver significant savings, Gartner says]() Original publisher: [Read original article]() Author: Simon Sharwood Published: 2026-09-15T07:23:34Z Content type: news Language: en Sources: [www.theregister.com - Articles]() Topics: [Google](), [Microsoft](), [Cloud]() Tags: [ai-and-ml](), [alternatives](), [cloud](), [copilot](), [gartner](), [gemini](), [google](), [google-workspace](), [microsoft](), [microsoft-365](), [saas]() ### AI overview The article reports that organizations switching from Microsoft 365 to Google are unlikely to save much money, according to Gartner. ### Source excerpt Nor are you likely to save much by making the move, says Gartner ## COBOL dev won .Net hackathon with help from AI - and their CIO loves it DevFeed: [COBOL dev won .Net hackathon with help from AI - and their CIO loves it]() Original publisher: [Read original article]() Author: Simon Sharwood Published: 2026-09-15T01:47:17Z Content type: news Language: en Sources: [www.theregister.com - Articles]() Topics: [AdventureX 2025](), [Artificial Intelligence](), [.NET](), [Development](), [coding]() Tags: [ai](), [ai-and-ml](), [australia](), [cobol](), [coding](), [copilot](), [dev](), [hackathon](), [mainframe](), [net](), [public-sector]() ### AI overview The article reports that a COBOL developer won a .NET hackathon with help from AI, a result praised by their CIO. The supplied summary also describes the Australia Taxation Office using Copilot practice to develop skills for future AI work. ### Source excerpt Australia Taxation Office sees footling with Copilot as a way to develop 'muscles' for real AI work ## AI SDK harness layer now supports native subscription authentication DevFeed: [AI SDK harness layer now supports native subscription authentication]() Original publisher: [Read original article]() Author: Felix Arntz Published: 2026-09-14T21:28:00Z Content type: release Language: en Sources: [Vercel News]() Topics: [vercel ai sdk](), [Authentication](), [OAuth](), [codex](), [Claude Code]() Tags: [ai](), [authentication](), [claude-code](), [codex](), [coding-agents](), [copilot](), [cursor](), [gateway](), [oauth](), [opencode](), [sdk]() ### AI overview The AI SDK harness layer now supports authenticating supported coding-agent harnesses through their native subscriptions. It uses explicit provider credentials when available, otherwise falls back to a host-native subscription without requiring code or configuration changes. ### Source excerpt The AI SDK harness layer now supports authenticating harnesses through their native subscriptions, where the underlying harness supports them. The harness layer runs different coding agents through the same HarnessAgent interface, so you can switch agents without changing your application code. No code changes or new settings are required. The direct authentication mode uses explicit provider environment credentials when they are present, and otherwise a native subscription found on the host. The default auto mode does the same when no AI Gateway credentials are set. The ai-gateway mode never reads native subscriptions. Native subscription credentials stay on the host. Just like with API keys, credentials are resolved at the host boundary. OAuth access tokens are refreshed there as needed. Where the sandbox supports it, the harness receives placeholder credentials and the real token is injected into outbound requests on the host. Native subscriptions work across harness adapters wherever the harness itself supports subscription login. These include Claude Code, Cline, Codex, Cursor, fx, GitHub Copilot, Grok Build, OpenCode, and Pi. Read the harness documentation to learn more. Read more ## C++ in the Age of AI: Visual Studio at CppCon 2026 DevFeed: [C++ in the Age of AI: Visual Studio at CppCon 2026]() Original publisher: [Read original article]() Author: Augustin Popa Published: 2026-09-14T19:34:43Z Content type: article Language: en Sources: [C++ Team Blog]() Topics: [C++](), [Visual Studio](), [GitHub Copilot](), [Visual Studio 2026](), [build performance](), [MSVC](), [debugging](), [Optimization](), [Refactoring](), [Artificial Intelligence]() Tags: [ai](), [build-optimization](), [build-performance](), [c-plus-plus](), [copilot](), [cppcon](), [debugging](), [github-copilot](), [msvc](), [visual-studio](), [visual-studio-2026]() ### AI overview This companion reading guide covers how Visual Studio 2026 is evolving C++ development with improved code navigation, build and runtime performance, language feature support, debugging, modernization, refactoring, and AI-assisted workflows using GitHub Copilot. ### Source excerpt At CppCon 2026, we shared how Visual Studio is evolving to help you work more effectively with large C++ codebases, improve build and runtime performance, adopt the latest language features, and incorporate AI into your existing workflows. This post is a companion reading guide for our session, C++ in the Age of AI: How Visual [...] The post C++ in the Age of AI: Visual Studio at CppCon 2026 appeared first on C++ Team Blog. ## What's New for C++ Developers in Visual Studio 2026 (18.7 - 18.10) DevFeed: [What's New for C++ Developers in Visual Studio 2026 (18.7 - 18.10)]() Original publisher: [Read original article]() Author: Augustin Popa Published: 2026-09-14T06:38:16Z Content type: article Language: en Sources: [C++ Team Blog]() Topics: [Visual Studio 2026](), [C++](), [GitHub Copilot](), [MSVC](), [AI-assisted coding](), [CMake](), [Git](), [Submodules]() Tags: [2026](), [build-optimization](), [c-plus-plus](), [cmake](), [copilot](), [git](), [modernization](), [msvc](), [submodules](), [testing](), [tools](), [visual-studio](), [visual-studio-2026]() ### AI overview This Microsoft C++ Team Blog post recaps Visual Studio 2026 versions 18.7 through 18.10 for C++ developers. It covers C++ reliability fixes, GitHub Copilot modernization for upgrading MSBuild and CMake projects to newer MSVC Build Tools, improved code navigation, discoverable MSVC Build Tools installations, Git worktrees and submodules in the IDE, and debugging improvements. ### Source excerpt Over the past few months, we have continued shipping monthly Visual Studio 2026 releases, delivering improvements across all stages of the development cycle. In this blog post, we'll recap everything that changed from version 18.7 through 18.10 (released this month) that is relevant for C++ developers. This includes new tools for maintaining and navigating C++ [...] The post What's New for C++ Developers in Visual Studio 2026 (18.7 - 18.10) appeared first on C++ Team Blog. ## Microsoft at CppCon 2026 DevFeed: [Microsoft at CppCon 2026]() Original publisher: [Read original article]() Author: Augustin Popa Published: 2026-09-14T00:16:42Z Content type: news Language: en Sources: [C++ Team Blog]() Topics: [C++](), [Microsoft](), [Visual Studio](), [Visual Studio 2026](), [GitHub Copilot](), [MSVC](), [Visual Studio Code](), [Artificial Intelligence](), [Optimization](), [CMake]() Tags: [ai](), [c-plus-plus](), [cmake](), [copilot](), [cppcon](), [github-copilot](), [microsoft](), [msvc](), [optimization](), [safety](), [survey](), [visual-studio](), [visual-studio-2026]() ### AI overview Microsoft's CppCon 2026 sessions cover modern C++ development, including AI-assisted workflows, MSVC, Visual Studio, Visual Studio Code, compiler optimization, C++ safety, and stricter compiler warnings. The article also provides conference logistics, speaker sessions, and a survey invitation. ### Source excerpt Microsoft will be at CppCon 2026 in Aurora, Colorado, which is taking place from September 14 through 18. Join us for talks from Microsoft speakers and colleagues across the C++ community and visit the Microsoft booth Monday through Thursday to meet the team and discuss the tools, technologies, and challenges that matter to you. If [...] The post Microsoft at CppCon 2026 appeared first on C++ Team Blog. ## AI Can Help Write an Article, but It Can't Stand Behind It DevFeed: [AI Can Help Write an Article, but It Can't Stand Behind It]() Original publisher: [Read original article]() Author: Raluca Budiu Published: 2026-09-11T17:00:00Z Content type: article Language: en Sources: [NN/g latest articles and announcements]() Topics: [Artificial Intelligence](), [Generative AI](), [User experience (UX)](), [Microsoft]() Tags: [ai](), [ai-authored](), [ai-content](), [ai-editing](), [ai-writing](), [article](), [copilot](), [genai](), [generative-ai](), [microsoft](), [ux](), [writing]() ### AI overview The article explains that NN/G uses AI during its editorial process for writing clarity, formatting, and critique, while humans retain editorial judgment and responsibility for published content. It describes a rigorous review cycle involving topic selection, multiple revisions, and checks for logical coherence, UX accuracy, and copy. AI tools such as Copilot in Microsoft Word and Grammarly help make writing more concise and clear, especially for authors who are not professional writers or speak English as a second language. ### Source excerpt NN/G uses AI for clarity, formatting, and critique, but humans retain editorial judgment and responsibility for every article. ## GitHub Copilot is now available in the AI SDK harness layer DevFeed: [GitHub Copilot is now available in the AI SDK harness layer]() Original publisher: [Read original article]() Author: Felix Arntz Published: 2026-09-10T17:39:00Z Content type: release Language: en Sources: [Vercel News]() Topics: [GitHub Copilot](), [vercel ai sdk](), [AI-assisted coding](), [cursor]() Tags: [agent](), [ai](), [claude](), [claude-code](), [code](), [codex](), [coding](), [copilot](), [cursor](), [github](), [github-copilot]() ### AI overview The AI SDK harness layer adds official GitHub Copilot support through an adapter, allowing applications to run Copilot and other coding agents through the same HarnessAgent interface. ### Source excerpt The AI SDK harness layer now supports GitHub Copilot through the official @ai-sdk/harness-github-copilot adapter. The harness layer lets your application run different coding agents through the same HarnessAgent interface, so you can switch agents without changing your application code. Pass githubCopilot to HarnessAgent: Under the hood, the adapter uses @ai-sdk/harness-acp to connect GitHub Copilot to HarnessAgent through the Agent Client Protocol (ACP). Supported harnesses now include, in addition to GitHub Copilot, Claude Code, Cline, Codex, Cursor, Deep Agents, fx, Grok Build, OpenCode, and Pi, with more coming soon. Read the GitHub Copilot harness documentation to get started. Read more ## Detect and disrupt AI-themed attacks with Microsoft Defender DevFeed: [Detect and disrupt AI-themed attacks with Microsoft Defender]() Original publisher: [Read original article]() Author: Rob Lefferts Published: 2026-09-10T16:00:00Z Content type: article Language: en Sources: [Microsoft Security Blog]() Topics: [Malware](), [Threat Research](), [spoofing](), [Microsoft]() Tags: [adversary-in-the-middle-aitm](), [ai](), [attacks](), [chatgpt](), [claude](), [copilot](), [credential-theft](), [deepseek](), [defender](), [github](), [malware](), [microsoft](), [phishing](), [security](), [social-engineering]() ### AI overview Microsoft describes AI-themed phishing, malvertising, credential theft, and malware campaigns that impersonate popular AI services and tools. It argues that attackers are exploiting trust and urgency around AI brands rather than compromising the referenced services. ### Source excerpt See how Microsoft Defender detects and disrupts AI-themed phishing, malware, and multi-stage attacks across the attack chain. The post Detect and disrupt AI-themed attacks with Microsoft Defender appeared first on Microsoft Security Blog. ## AI uprising postponed after Copilot falls off the web DevFeed: [AI uprising postponed after Copilot falls off the web]() Original publisher: [Read original article]() Author: Richard Speed Published: 2026-09-10T10:30:50Z Content type: news Language: en Sources: [www.theregister.com - Articles]() Topics: [AI Chat]() Tags: [ai](), [ai-and-ml](), [copilot](), [microsoft](), [microsoft-365](), [outage](), [resilience](), [web]() ### AI overview Copilot's chatbot was unavailable for 100 minutes because of Error 1016, while a separate resilience drill also affected suggestions. ### Source excerpt Error 1016 kept the chatbot quiet for 100 minutes while a separate resilience drill swallowed suggestion pills ## Today I will... find hidden latency across a distributed .NET application DevFeed: [Today I will... find hidden latency across a distributed .NET application]() Original publisher: [Read original article]() Author: Justin Yoo Published: 2026-09-08T16:00:22Z Content type: tutorial Language: en Sources: [Visual Studio Blog]() Topics: [.NET](), [Processes](), [GitHub Copilot]() Tags: [copilot](), [github-copilot](), [github-copilot-profiler-agent](), [latency](), [net](), [performance](), [processes](), [productivity](), [profile](), [visual-studio](), [visual-studio-2026](), [visual-studio-profiler]() ### AI overview A Visual Studio profiling walkthrough for finding hidden latency in a distributed .NET application by isolating the process responsible for a slow interaction and determining whether it is computing or waiting. ### Source excerpt When a distributed application feels slow, the user sees one delay. The code behind that delay may run across a web frontend, backend services, databases, and external APIs. If you profile only the frontend while the backend is slow, the profiler can show that the frontend is healthy without revealing the actual bottleneck. This article [...] The post Today I will... find hidden latency across a distributed .NET application appeared first on Visual Studio Blog. ## GitHub Copilot app for Beginners: Run several agents at once DevFeed: [GitHub Copilot app for Beginners: Run several agents at once]() Original publisher: [Read original article]() Author: Kayla Cinnamon Published: 2026-09-03T16:00:00Z Content type: tutorial Language: en Sources: [GitHub Engineering]() Topics: [AI Chat]() Tags: [agents](), [ai](), [ai-agents](), [ai-ml](), [copilot](), [developer](), [developer-tools](), [development](), [git](), [github](), [github-copilot](), [github-copilot-app](), [github-copilot-app-for-beginners]() ### AI overview A beginner tutorial on using the GitHub Copilot app to run several AI agent sessions in parallel. It explains that sessions are isolated through separate Git worktrees and retain their own context, then demonstrates concurrent feature work, accessibility review, and testing. ### Source excerpt Learn how to run parallel agents in the GitHub Copilot app, and experience the moment it stops feeling scary and starts feeling powerful. The post GitHub Copilot app for Beginners: Run several agents at once appeared first on The GitHub Blog. ## Why Short AI Coding Prompts Can Cost You More Time DevFeed: [Why Short AI Coding Prompts Can Cost You More Time]() Original publisher: [Read original article]() Author: Dean Hume Published: 2026-09-03T09:17:56Z Content type: opinion Language: en Sources: [Dean Hume]() Topics: [Prompt Engineering](), [ai-coding](), [GitHub Copilot](), [Artificial Intelligence](), [Agent Harness](), [GitHub Copilot CLI](), [Testing]() Tags: [agent-harness](), [ai](), [ai-coding](), [coding](), [copilot](), [github-copilot](), [prompt](), [testing]() ### AI overview This opinion article connects GitHub Copilot team's findings about compressing tool output with everyday AI coding prompts. It argues that optimizing a visible step, such as shortening a response or prompt, can increase total time and cost when missing details force follow-up questions, reruns, or recovery work. It recommends giving coding assistants the full problem and relevant source material, and treating instruction files carefully because rewriting guidance can change agent behavior. ### Source excerpt Ever tried to save time by keeping a prompt short - only to spend the next ten minutes answering follow-up questions because the AI didn't have what it needed? Yeah, me too. I recently came across a really interesting post from the GitHub Copilot team about making ## Visual Studio Code 1.136 DevFeed: [Visual Studio Code 1.136]() Original publisher: [Read original article]() Author: Visual Studio Code Team Published: 2026-09-02T17:00:00Z Content type: release Language: en Sources: [Visual Studio Code - Code Editing. Redefined.]() Topics: [AI Bots]() Tags: [agents](), [claude](), [copilot](), [pull-request](), [release](), [vs-code]() ### AI overview Visual Studio Code 1.136 adds agent-focused workflows for completing pull requests and working across multi-root workspaces and related chats. ### Source excerpt Learn what is new in Visual Studio Code 1.136 Read the full article ## Today I will... review GitHub PRs DevFeed: [Today I will... review GitHub PRs]() Original publisher: [Read original article]() Author: Aaron Powell Published: 2026-09-01T16:00:27Z Content type: tutorial Language: en Sources: [Visual Studio Blog]() Topics: [Pull Request](), [GitHub](), [GitHub Copilot](), [Syntax Highlighting]() Tags: [copilot](), [git](), [github](), [productivity](), [pull-requests](), [review](), [tooling](), [visual-studio](), [visual-studio-2026]() ### AI overview A tutorial on reviewing GitHub pull requests from Visual Studio. It covers opening PRs, examining diffs, adding buffered inline comments, approving or merging, and using Copilot during review. ### Source excerpt Today I will show you how we can tackle one of the most common tasks when working in a development team or managing an open-source project, and that is working with Pull Requests. While we're going to be using the GitHub tooling within Visual Studio for this, the approach would be very similar with Azure [...] The post Today I will... review GitHub PRs appeared first on Visual Studio Blog. ## GitHub Copilot app for Beginners: Automate Dependabot pull request triage DevFeed: [GitHub Copilot app for Beginners: Automate Dependabot pull request triage]() Original publisher: [Read original article]() Author: Christopher Harrison Published: 2026-08-26T20:12:53Z Content type: tutorial Language: en Sources: [GitHub Engineering]() Topics: [GitHub Copilot app](), [pull-requests](), [Automation](), [GitHub Copilot](), [GitHub](), [Vulnerabilities]() Tags: [ai-ml](), [automation](), [copilot](), [developer](), [github](), [github-copilot](), [github-copilot-app](), [github-copilot-app-for-beginners](), [pull-request](), [workflow]() ### AI overview Learn how to create a daily automation in the GitHub Copilot app to triage Dependabot pull requests. The automation reviews open pull requests, groups updates by risk, checks CI status, and returns a summary highlighting changes ready to merge or requiring closer attention. ### Source excerpt Managing library updates can be tedious at times. Learn how the GitHub Copilot app can handle this type of repetitive task. The post GitHub Copilot app for Beginners: Automate Dependabot pull request triage appeared first on The GitHub Blog. ## Visual Studio Code 1.135 DevFeed: [Visual Studio Code 1.135]() Original publisher: [Read original article]() Author: Visual Studio Code Team Published: 2026-08-26T17:00:00Z Content type: release Language: en Sources: [Visual Studio Code - Code Editing. Redefined.]() Topics: [AI-assisted coding](), [AI Chat](), [SDKs]() Tags: [agents](), [claude](), [copilot](), [github-copilot](), [release](), [vs-code]() ### AI overview Visual Studio Code 1.135 adds support for continuing recent Copilot or Claude agent sessions from other applications, an experimental Rubber Duck second-opinion feature, streamlined Agents-window controls, and per-model chat token usage details. ### Source excerpt Learn what's new in Visual Studio Code 1.135 Read the full article ## The Visual Studio Debugger Agentic Workflow Gets a Test-Driven Upgrade DevFeed: [The Visual Studio Debugger Agentic Workflow Gets a Test-Driven Upgrade]() Original publisher: [Read original article]() Author: Harshada Hole Published: 2026-08-26T16:00:47Z Content type: article Language: en Sources: [Visual Studio Blog]() Topics: [debugging](), [AI-assisted coding]() Tags: [agent](), [agentic](), [bug](), [copilot](), [debugger](), [debugging](), [debugging-and-diagnostics](), [devops](), [diagnostics](), [github](), [visual-studio](), [visual-studio-2026](), [workflow]() ### AI overview Visual Studio Debugger Agent adds a test-driven investigation workflow that creates or identifies a focused failing test, debugs it to find the root cause, and reruns it to validate a fix. It is intended for issues without reliable manual reproduction steps when supported test infrastructure is available. ### Source excerpt A few months ago, we introduced a new guided agentic workflow in the Visual Studio Debugger Agent designed to help you move from a bug report to a verified fix without spending your morning guessing where to begin. If you missed that announcement, check out Stop Hunting Bugs: Meet the New Visual Studio Debugger Agent [...] The post The Visual Studio Debugger Agentic Workflow Gets a Test-Driven Upgrade appeared first on Visual Studio Blog. ## Visual Studio August Update - Work Smarter Across Models and Branches DevFeed: [Visual Studio August Update - Work Smarter Across Models and Branches]() Original publisher: [Read original article]() Author: Mark Downie Published: 2026-08-25T16:00:00Z Content type: release Language: en Sources: [Visual Studio Blog]() Topics: [Visual Studio 2026](), [GitHub Copilot](), [Language models](), [AI-assisted coding]() Tags: [agents](), [copilot](), [git](), [github-copilot](), [models](), [update](), [visual-studio]() ### AI overview Visual Studio 2026's August update adds adjustable Copilot model thinking effort, organization-level custom agents, and Copilot usage access. It also improves Git workflows with worktrees and submodule support. ### Source excerpt Tune Copilot model thinking effort, share custom agents across your organization, track usage, and simplify complex Git workflows with worktrees and submodule support. The post Visual Studio August Update - Work Smarter Across Models and Branches appeared first on Visual Studio Blog. ## Today I will... Modernize a .NET application DevFeed: [Today I will... Modernize a .NET application]() Original publisher: [Read original article]() Author: Matt Soucoup, Pablo Lopes Published: 2026-08-21T17:00:45Z Content type: tutorial Language: en Sources: [Visual Studio Blog]() Topics: [.NET]() Tags: [copilot](), [github-copilot](), [modernization](), [net](), [net-framework](), [tooling](), [visual-studio]() ### AI overview A tutorial on using GitHub Copilot modernization tooling in Visual Studio to upgrade a .NET Framework application to .NET 10. It describes Guided mode, which pauses at assessment, planning, and execution checkpoints for review and source-control records. ### Source excerpt Today I will modernize a .NET Framework application to .NET 10 using the GitHub Copilot modernization tooling built-in to Visual Studio. The tooling helps us upgrade applications running on legacy versions of .NET and also migrate them to Azure. Today we're going to focus on the upgrade portion. And, the tooling will do [...] The post Today I will... Modernize a .NET application appeared first on Visual Studio Blog. ## Visual Studio Code 1.134 DevFeed: [Visual Studio Code 1.134]() Original publisher: [Read original article]() Author: Visual Studio Code Team Published: 2026-08-19T17:00:00Z Content type: release Language: en Sources: [Visual Studio Code - Code Editing. Redefined.]() Topics: [Visual Studio Code](), [GitHub Copilot](), [AI-assisted coding](), [SDKs](), [Processes]() Tags: [agents](), [copilot](), [github-copilot](), [html](), [release](), [vs-code]() ### AI overview Visual Studio Code 1.134 adds side-by-side chat organization, prompt navigation and search, local HTML preview, and an agent host that can connect an agent session across multiple VS Code windows. ### Source excerpt Learn what's new in Visual Studio Code 1.134 Read the full article ## Benchmarks Are Free Now DevFeed: [Benchmarks Are Free Now]() Original publisher: [Read original article]() Author: Daniel Doubrovkine (dblock@dblock.org) Published: 2026-08-15T00:00:00Z Content type: article Language: en Sources: [Daniel Doubrovkine]() Topics: [Ruby](), [Benchmark](), [Polymorphism](), [GitHub Copilot CLI]() Tags: [ai](), [benchmarks](), [caching](), [cli](), [copilot](), [open-source](), [performance](), [ruby]() ### AI overview A Ruby enum inheritance fix was correct but made subclass lookups about five times slower because merged enum hashes were rebuilt on every call. Benchmarks generated with Copilot CLI exposed the regression, and memoization restored subclass performance to the base-class level. Additional benchmarks quantified the gem's small overhead for hash-backed lookups and much larger overhead for exhaustive matching. ### Source excerpt My previous post walked through four bugs in ruby-enum, a gem I maintain, all stemming from the fact that class-level instance variables aren't inherited by subclasses. The third fix, #59, made keys, key?, value?, key, value, to_h, parse and each walk up superclass and merge in a parent's enums, so a subclass would see everything its ancestors defined. It was correct, fully tested, and shipped. It also made every one of those methods roughly 5x slower on any subclass. def _enum_hash if superclass < Ruby::Enum superclass.send(:_enum_hash).merge(_own_enum_hash) else _own_enum_hash end end This recomputes the merged hash, walking the entire ancestor chain, on every single call. There's no caching. A one-level subclass calling .value pays for building a brand new hash, on top of the superclass doing the same, every time. The test suite didn't notice because tests check correctness, not speed, and correctness was fine. I only found this because I asked Copilot CLI to add a benchmark script comparing lookups at different inheritance depths, mostly out of curiosity about how the "Benchmarks" section of the README would read next to the new feature. It took one prompt and about a minute to get a working script: class Colors include Ruby::Enum define :RED, 'red' define :GREEN, 'green' end class SubColors < Colors define :BLUE, 'blue' end class SubSubColors < SubColors define :YELLOW, 'yellow' end benchmark('base class (no inheritance)', n) { Colors.value(:RED) } benchmark('subclass (1 level)', n) { SubColors.value(:RED) } benchmark('sub-subclass (2 levels)', n) { SubSubColors.value(:RED) } The first run told the story immediately: a 1-level subclass's .value calls took roughly 5x as long as the base class, and a 2-level subclass was worse still. Nobody had written this benchmark before merging #59 because writing a throwaway benchmark script used to feel like more ceremony than it was worth for a one-off performance check. Now it's a single sentence to an agent, and the scri [Next page]()