- Visual Studio and VS Code combine classic debugging tools with AI features like Copilot, IntelliCode and Copilot Chat to streamline bug fixing and test creation.
- Advanced breakpoint types, multi‑target sessions, profiling and Test Explorer integration make it easier to diagnose and optimize application behavior.
- AI assistants such as GitHub Copilot, DotRush and external multi‑agent platforms help generate tests, explain failures, propose fixes and review code at scale.
- Choosing the right mix of built‑in and third‑party AI tools lets teams enhance reliability, performance and security without abandoning familiar Visual Studio workflows.
Debugging and testing inside Visual Studio and Visual Studio Code have evolved from classic breakpoints and watch windows into an ecosystem powered by AI assistants, smart extensions and powerful profilers. Instead of spending hours stepping line by line, you can now lean on tools like GitHub Copilot, IntelliCode, Copilot Chat and a new wave of agentic code assistants (AI tools for debugging and development) that help you configure debuggers, write and run tests, profile performance and even iterate on fixes automatically.
If you work with C#, .NET, JavaScript, TypeScript or any other modern stack, there is a rich toolbox that blends the familiar Visual Studio debugger with AI‑driven guidance, automated test generation and code review. In this guide we are going to walk through how debugging works in Visual Studio Code and the full Visual Studio IDE, how AI plugs into those workflows, and which external assistants can supercharge debugging and testing without locking you into a single vendor.
Debugging basics in Visual Studio Code
Visual Studio Code ships with first‑class debugging support for JavaScript, TypeScript and Node.js (see Node.js tutorial for beginners), and can be extended to almost any language through marketplace extensions. The core workflow is still the same: configure a debug target, set breakpoints, start a session and inspect the program state as it runs.
The debugger user interface in VS Code is organized around the Run and Debug view, a compact toolbar, the debug console and the side bar panels for call stack, variables and watch expressions. Together they let you start and control sessions, jump between stack frames, and track the values that matter while your code pauses at breakpoints.
Before you can debug most projects you either rely on VS Code’s automatic configuration or define a dedicated launch.json file that describes how to run your app under the debugger. Simple scripts often run directly via F5, while complex backends, multi‑service apps or remote processes require explicit launch configurations and attach settings.
Starting a session is usually as straightforward as opening the file that contains your entry point and pressing F5 or choosing Run and Debug in the side bar. VS Code will ask which debugger to use (for example, Node, .NET, Python or C++) and will then open the DEBUG CONSOLE, switch the status bar color and show the currently active configuration so you always know what is running.
Once execution is paused, the debug toolbar appears with the standard controls to continue, pause, step over, step into, step out, restart or stop the program. If you are debugging several targets at once, such as a client and a server, the toolbar lets you choose which session is active so your step commands apply to the correct process.
Mastering breakpoints, logpoints and advanced debug features
Breakpoints are still the heart of any debugging workflow in VS Code, but the editor gives you far more than simple line breaks. You can click in the left margin to toggle a standard breakpoint, use F9 on the current line, or manage them centrally in the BREAKPOINTS section of the Run and Debug view.
Visual cues help you understand the state of each breakpoint at a glance: solid red circles mean active, muted gray circles indicate disabled, and hollow icons show breakpoints that could not be properly registered with the target debugger. For better visibility, you can even enable markers in the overview ruler so hot spots in your code stand out while you scroll.
Conditional breakpoints let you pause only when a specific expression is true, when a given hit count threshold is reached, or when another breakpoint has already fired. You add them by right‑clicking in the margin and choosing Add Conditional Breakpoint, then specifying the condition, hit count or trigger relationship you want.
Triggered breakpoints are especially useful for flaky failures that occur only after a certain precondition, such as a certain request sequence or a particular method being called first. You wire them up by selecting Add Triggered Breakpoint and linking them to the breakpoint that should enable them.
Inline breakpoints address the headache of minified or extremely dense lines of code by letting you attach a breakpoint to a specific column instead of just a line. Using Shift+F9 during a debug session you can place them exactly where you need, even if there are multiple statements on a single line, and they can also carry conditions if required.
Function and data breakpoints take things further by letting you stop when a named function is hit or when a particular variable is accessed, read or modified. Function breakpoints are entered from the BREAKPOINTS header with a function name, while data breakpoints are usually created from the VARIABLES view via commands like Break on Value Change or Break on Access.
Logpoints behave like ‘non‑breaking’ breakpoints: instead of stopping execution they print a custom message to the debug console whenever execution passes through. You can include expressions in curly braces inside the message template, so you get live insights similar to temporary logging without touching the source code.
Inspecting state: variables, watch expressions and the debug console
When your program is paused, VS Code gives you several ways to inspect and manipulate state so you can test hypotheses quickly. The VARIABLES section in the Run and Debug view lists locals, arguments and globals for the selected stack frame, while hovering over symbols in the editor pops up tooltips with their current values.
You can modify variables directly from the VARIABLES panel by choosing Set Value, which is handy for exploring how different inputs influence behavior without restarting the program. Copy Value and Copy as Expression make it easy to paste exact expressions into other places, especially into the WATCH list or debug console.
The WATCH section lets you track arbitrary expressions across steps and stack frames, keeping a focused list of the values that really matter for the bug you are chasing. You can filter variables by name or value with a dedicated keyboard shortcut so long lists remain manageable.
The Debug Console doubles as a REPL, enabling you to evaluate arbitrary expressions in the context of the selected frame. You get syntax coloring, indentation and language‑aware editing, plus multi‑line input using Shift+Enter, which is perfect for trying out fixes or calling helper functions on the fly.
Multi‑target debugging in VS Code kicks in when you run several debug sessions at once, for example a browser client and Node.js backend or different microservices. Each session appears as a top‑level item in the CALL STACK view, the toolbar shows which one is active, and all actions operate on the selected session until you switch.
Remote debugging and debugger extensions in VS Code
Remote debugging support in VS Code depends on the language‑specific extension you are using, with one notable built‑in exception: the Node.js debugger can attach to remote processes out of the box. For other runtimes like Python, .NET, Go or PHP you install the relevant debug extensions and follow their documentation for remote or container scenarios.
The Visual Studio Marketplace is packed with debugger extensions that add support for runtimes such as C#, C++, Python, PHP, Ruby, Go, PowerShell and more. Many of them integrate nicely with launch.json, support advanced features like data breakpoints, and even plug into container orchestrators or cloud debuggers.
If you need custom behavior, VS Code also allows you to build your own debugger extension, using the Debugger Extension documentation and sample projects as a starting point. This is particularly valuable for proprietary runtimes or internal frameworks where off‑the‑shelf tooling does not exist.
Debugging and testing in full Visual Studio with Test Explorer
Inside the full Visual Studio IDE, unit testing and debugging are tightly integrated via Test Explorer, which makes it easy to run and step through tests alongside the code under test. You simply set breakpoints in your test methods, choose the tests you care about in Test Explorer, and start a debugging session directly from there.
When you select Debug on one or more tests, Visual Studio launches the test runner under the debugger so you can move seamlessly between test code and implementation. This flow is ideal for TDD, for investigating failing tests or for validating complex edge cases where you want fine‑grained control.
Visual Studio 2022 expands this workflow with deep performance profiling for individual test methods, starting with version 17.8 where any relevant Performance Profiler tool can be attached to a test. You can right‑click a method in Test Explorer, select Profile, choose a profiler such as Instrumentation or CPU Usage, and analyze why a test is slow or memory‑hungry.
Profiling tests in isolation is extremely useful to confirm that micro‑optimizations actually pay off, as you can run the profiler, adjust the implementation and measure the impact in a tight loop. This keeps performance work grounded in real data instead of assumptions.
AI help for debugging tests with GitHub Copilot in Visual Studio
Recent Visual Studio releases introduce GitHub Copilot‑powered features that specifically target debugging and fixing failing tests. Starting with Visual Studio 2022 17.12 Preview 2, if you have an active Copilot subscription you can ask the IDE to explain or debug failed tests right from Test Explorer.
Two context‑aware commands appear when you right‑click a failing test: Explain failure with Copilot and Debug with Copilot. The first one gives you a natural‑language explanation of why the assertion failed based on the test output and code, while the second one drives a more interactive debugging flow.
When you choose to debug with Copilot, Visual Studio launches the Copilot Debugger Agent, which behaves much like an AI pair programmer focused specifically on the failing test. It proposes a hypothesis about the root cause, applies targeted edits, reruns the test under the debugger, and iterates as needed until the failure is resolved or further input is required.
Throughout this loop the agent also generates a detailed summary of what it changed and why, so you can review the diff, understand the reasoning and decide whether to keep or adjust the fix. You remain in control, but the heavy lifting of trial‑and‑error debugging is handled by the AI.
Another Copilot‑assisted debugging flow in Visual Studio provides a ‘debug plan’ for complex issues, automatically sets appropriate breakpoints and watch expressions, and kicks off a session for you. As the debugger pauses, Copilot inspects the live values, decides whether to continue stepping or propose a code change, and keeps the conversation going in Copilot Chat until you reach a passing state.
GitHub Copilot and Copilot Chat for daily debugging and testing
Beyond these specialized flows, GitHub Copilot in Visual Studio and VS Code continuously assists you while writing, debugging and testing code. It offers inline completions that can span entire lines or multi‑line blocks, often guessing the implementation of a method or the setup of a test just from a comment or function signature.
Copilot Chat adds an interactive side panel and inline Ask Copilot capability, letting you ask questions in plain English like “why is this exception thrown here?” or “write xUnit tests for this method with edge cases included”. The assistant responds with annotated code, explanations and often directly suggested test methods.
Because Copilot has access to the current file and surrounding context, its answers are usually more relevant than a generic web search, especially when you are navigating a large or unfamiliar codebase. You can refine the suggestions, request alternative approaches or ask it to focus purely on writing tests, on debugging or on profiling hints.
One of the underrated uses of Copilot Chat is having it analyze a stack trace, error log or profiler output and translate it into a clear sequence of steps to reproduce and fix. This shortens the gap between noticing a failure and forming a solid debugging strategy.
IntelliCode: AI‑driven IntelliSense that helps prevent bugs
Microsoft IntelliCode complements Copilot by enhancing IntelliSense with AI‑ranked suggestions and whole‑line completions based on patterns learned from thousands of public repositories. Instead of showing all possible members alphabetically, IntelliCode pushes the most likely and most correct ones to the top, marked with a star icon.
This context‑aware ranking subtly improves debugging because you are less likely to pick the wrong overload or property when wiring up code, which in turn reduces the number of runtime issues you have to chase later. It’s like having a silent reviewer nudging you toward the APIs and patterns that are commonly used correctly.
IntelliCode can also detect when you are making the same edit in several places and proposes an automatic repeated‑edits fix so you do not miss a location and introduce inconsistent behavior. That is especially relevant in bug‑fixing sessions where a pattern must be updated across many files.
Since IntelliCode runs locally in the Visual Studio environment, it does not need to ship your code to external services for ranking suggestions, improving privacy while still providing intelligent completions. It supports languages such as C#, XAML, C++, JavaScript, TypeScript and Visual Basic in the Visual Studio IDE.
DotRush: lightweight C# debugging, testing and profiling in VS Code
For developers who love VS Code but need a powerful C# experience, DotRush is an open‑source extension that brings debugging, testing and profiling capabilities similar to the full Visual Studio environment. It is lightweight, fast and works not only in VS Code but also in compatible forks, Neovim and Zed.
DotRush offers the standard IntelliSense set (auto‑completion, go to definition, find references, refactoring, renaming) alongside a built‑in decompiler that can show actual C# code for assemblies, including core System libraries. That alone is a strong debugging ally when you need to understand framework behavior.
The extension analyzes all target frameworks in a multi‑targeted project at once, so you can see errors for .NET Framework and .NET Core without switching context. This saves time when debugging cross‑platform code because incompatibilities show up immediately.
DotRush uses VSDBG for VS Code and NetCoreDbg for other editors, and your existing launch.json files from the classic C# extension are fully compatible. You can simply press F5, pick .NET Core Debugger and let the extension build and launch the project for debugging without complex setup.
You can choose a startup project by right‑clicking its file or folder and marking it as Startup Project, mirroring the behavior of full Visual Studio and making multi‑project solutions easier to debug. DotRush also respects Properties\LaunchSettings.json when starting a debug session, even with NetCoreDbg.
On top of this, DotRush includes Unity and Godot debugging support, a built‑in Test Explorer for NUnit and xUnit, and .NET profiling tools that can trace execution or capture heap dumps. Profiling sessions can be launched alongside the debugger or attached to existing processes, with reports stored in the project directory for later inspection.
The broader landscape of AI coding assistants for debugging and testing
Visual Studio’s built‑in AI is only part of the story; there is an entire ecosystem of external AI coding assistants that integrate with VS Code, JetBrains and other environments to help with debugging, testing and code quality. These tools vary widely in focus, from pure autocomplete to full multi‑agent code review platforms.
Platforms like Qodo center on code quality across the whole SDLC, with specialized agents for generating code and tests, improving test coverage and performing AI‑driven pull request reviews. They integrate with IDEs, terminals and CI pipelines to keep code, tests and review comments aligned with organizational standards.
Other assistants such as GitHub Copilot (outside Visual Studio), Tabnine, Replit’s AI, Amazon Q Developer, AskCodi, Sourcegraph Cody, DeepCode AI, Figstack, CodeGeeX and CodeGPT each bring their own strengths to debugging and testing. Some focus on real‑time syntax suggestions and refactoring, others on security scanning, code explanation, cross‑language translation or automated test creation.
Agent‑oriented tools like Cline, Augment Code, Gemini CLI and Qwen3‑Coder push the idea further by planning multi‑step tasks, editing files, running terminal commands and iterating on feedback almost like a junior engineer operating under your supervision. This can be particularly powerful for repetitive debugging chores or bulk refactoring that would otherwise be tedious.
When evaluating these assistants for debugging scenarios, it is worth considering factors like language coverage, IDE integration, privacy and on‑prem options, ability to understand large codebases, and how well they handle test generation, security checks and performance hints. Enterprise teams often care as much about governance and compliance as about raw AI capability.
AI coding assistants are not a replacement for solid debugging skills or thoughtful test design, but they are rapidly becoming essential companions that handle boilerplate, surface non‑obvious issues and keep you focused on the parts of the problem that really require human judgment. Used well, they shorten feedback loops and make Visual Studio and VS Code feel far more responsive to how you actually work.
Bringing all of this together, modern debugging and testing in Visual Studio is less about memorizing every shortcut and more about orchestrating classic tools (breakpoints, watch windows, profilers) with AI helpers like Copilot, IntelliCode, DotRush and external agents so that configuration, diagnosis and iteration flow almost continuously as you code. Once you get comfortable combining the debugger UI with AI‑assisted analysis, test generation and performance profiling, the effort needed to track down bugs, understand failures and keep your test suite healthy drops dramatically.
