In this post, we\u2019ll walk through two real-world scenarios using the eShopLite<\/a> sample solution:<\/p>\n As developers, we know unit tests are critical to maintainable software. But let\u2019s be honest: writing unit tests is not always the most exciting part of the job (I know, that’s maybe just me). That\u2019s where GitHub Copilot Coding Agent can help.<\/p>\n We start by asking Copilot to analyze the solution and identify gaps in the test coverage.<\/p>\n Prompt used:<\/strong><\/p>\n Copilot provides a structured proposal with clear rationales and expected outcomes. This helps developers quickly validate whether the suggested tests align with project requirements.<\/p>\n Once we are satisfied with the list, we instruct Copilot to create a GitHub Issue that contains all the details of the missing unit tests.<\/p>\n Prompt used:<\/strong><\/p>\n \ud83d\udc49 Example issue: #47 Implement missing Unit Tests<\/a><\/p>\n <\/i>Note<\/strong><\/p>In order to create the issue, we use the GitHub MCP Server tools with Copilot.<\/div><\/p>\n The last step is to assign the issue to the Copilot Coding Agent. From here, Copilot automatically generates the tests, opens a pull request, and awaits human review.<\/p>\n Prompt used:<\/strong><\/p>\n \ud83d\udc49 Example PR: #48 Add Unit Tests<\/a><\/p>\n This workflow reduces the manual burden of writing boilerplate tests and helps ensure consistent test quality across the solution.<\/p>\n The second scenario demonstrates how Copilot Coding Agent can go beyond testing and actually implement new functionality. Instead of jumping directly into code, we start with a Product Requirements Document (PRD)<\/strong>.<\/p>\n We ask Copilot to draft a PRD that captures the intent and requirements of adding a mock payment service.<\/p>\n Prompt used:<\/strong><\/p>\n The generated PRD is not just filler text; it provides actionable details like endpoints, environment variables, and acceptance criteria. This ensures that both developers and stakeholders are aligned before any code is written.<\/p>\n Once the PRD is approved, we pass it to Copilot Coding Agent to implement the desired features.<\/p>\n Copilot creates the code changes, updates configurations, and even generates UI elements where needed. It will also use MCP tools, like Playwright, to capture screenshots and validate the end-to-end experience.<\/p>\n \ud83d\udc49 Example PR: #49 Implement Mock Payment Server<\/a><\/p>\n This shows the real potential: using AI to bridge documentation, planning, and execution<\/strong>. Copilot doesn\u2019t just help you type faster\u2014it helps you ship features faster.<\/p>\n GitHub Copilot Coding Agent represents a shift in how .NET developers can approach productivity.<\/p>\n Instead of replacing developers, it augments their workflow, automating repetitive steps and letting humans focus on creativity, design, and review.<\/p>\n If you\u2019re working with .NET and haven\u2019t tried Copilot Coding Agent yet, now is the perfect time to experiment. And remember, you can customize how the Coding Agent works in your repo with AGENTS.md custom instructions\u2014see the Copilot Coding Agent changelog announcement<\/a>.<\/p>\n <\/i>Caution<\/strong><\/p>While Copilot can successfully implement missing unit tests and even generate new features, it is critical to carefully review the generated code before merging. Human oversight ensures code quality, security, and alignment with project standards.<\/div><\/p>\n See how GitHub Copilot Coding Agent automates unit tests and ships features from a PRD in a real .NET sample, so you can focus on design and review.<\/p>\n","protected":false},"author":120281,"featured_media":57934,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[685,7781,756],"tags":[568,7869],"class_list":["post-57933","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dotnet","category-ai","category-csharp","tag-ai","tag-github-copilot"],"acf":[],"blog_post_summary":" See how GitHub Copilot Coding Agent automates unit tests and ships features from a PRD in a real .NET sample, so you can focus on design and review.<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts\/57933","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/users\/120281"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/comments?post=57933"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts\/57933\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/media\/57934"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/media?parent=57933"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/categories?post=57933"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/tags?post=57933"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
\nScenario 1: Automating Unit Tests with Copilot<\/h3>\n
Step 1 \u2013 Identify Missing Unit Tests<\/h4>\n
Analyze the current solution and propose unit tests to add in the scenario \r\n[scenarios\\01-SemanticSearch].\r\nMake a list of tests where each element has title, description, rationale, \r\naffectedFiles (paths), testMethodName, testCases (objects with name, arrange, \r\nact, assert, optional expected), dependencies (to mock), priority \r\n(High|Medium|Low), and complexity (Small|Medium|Large).\r\nKeep suggestions actionable and use repo-relative file paths.<\/code><\/pre>\n![\"Identify](\"https:\/\/devblogs.microsoft.com\/dotnet\/wp-content\/uploads\/sites\/10\/2025\/09\/10-identifymissingunittests.png\")
<\/p>\nStep 2 \u2013 Review Suggested Tests<\/h4>\n
![\"Suggested](\"https:\/\/devblogs.microsoft.com\/dotnet\/wp-content\/uploads\/sites\/10\/2025\/09\/12-unittest-done.png\")
<\/p>\nStep 3 \u2013 Create GitHub Issue<\/h4>\n
Given the current list of missing unit tests, create a new GitHub issue titled \r\n\"Implement missing Unit Tests\".\r\nThe new GitHub issue content should describe each missing test to be implemented later.\r\nShow the ID and URL of the new created Issue in the current repository.<\/code><\/pre>\n![\"Generated](\"https:\/\/devblogs.microsoft.com\/dotnet\/wp-content\/uploads\/sites\/10\/2025\/09\/15-generate-ghissue.png\")
<\/p>\nStep 4 \u2013 Assign to Copilot Coding Agent<\/h4>\n
assign the new issue to @copilot<\/code><\/pre>\n
\nScenario 2: Implementing a Feature with a Mock Payment Server<\/h3>\n
Step 1 \u2013 Generate PRD<\/h4>\n
Create a new Markdown file named `04-PRD_Add_Payment_Mock_Server.md` containing a \r\nProduct Requirements Document (PRD) titled \"PRD: Add Mock Payment Server \/ Payment \r\nService to eShopLite\".\r\nKeep the document business-focused and concise. Include sections: Purpose, Scope, \r\nKey success criteria, Quick checklist, Assumptions, High-level design overview, API \r\ncontract summary, Data model summary, Implementation notes, Configuration & local \r\ndefaults, Security & privacy notes, Testing & validation, Acceptance criteria, \r\nRollout plan, and Appendix with example request\/response JSON.<\/code><\/pre>\nStep 2 \u2013 Implement PRD<\/h4>\n
![\"PRD](\"https:\/\/devblogs.microsoft.com\/dotnet\/wp-content\/uploads\/sites\/10\/2025\/09\/20-implementPRD.png\")
<\/p>\n![\"Payment](\"https:\/\/devblogs.microsoft.com\/dotnet\/wp-content\/uploads\/sites\/10\/2025\/09\/25-paymentPRIncludeScreenShots.png\")
<\/p>\n
\nSummary<\/h2>\n
\n
\nReferences<\/h2>\n
\n