Add file-based Copilot instructions for backend, frontend, and tests

[Copilot]

Implements area-specific GitHub Copilot guidance using file-based instructions that activate automatically based on file patterns.

Implementation

.github/instructions/backend.instructions.md

• Pattern: backend/**/*.java
• Spring Boot: REST conventions, JPA patterns, circuit breaker with Resilience4j
• H2-primary architecture, Feign client configuration, actuator patterns

.github/instructions/frontend.instructions.md

• Pattern: frontend/**/*.{jsx,tsx,js,ts}
• Vite build patterns, Material-UI theming (Navy #003366, Teal #008080)
• React Query for server state, React Router v6, component organization

.github/instructions/tests.instructions.md

• Pattern: tests/**/*.{js,ts}
• Playwright: role-based locators, auto-waiting patterns, POM guidelines
• Multi-viewport testing, fixture synchronization with H2 seed data

COPILOT_INSTRUCTIONS.md

• Documentation: pattern-matching system, non-overlapping applyTo rules
• Repo-specific customizations, integration with existing instructions

Structure

Each instruction file uses YAML frontmatter for pattern matching:

---
name: 'Backend Java Development'
description: 'Guidelines for Spring Boot backend development'
applyTo: 'backend/**/*.java'
---

All instructions adapted from github/awesome-copilot templates with Three Rivers Bank project-specific customizations.

Original prompt

Overview

Implement file-based instructions for the agentic-devops-demo monorepo to provide area-specific Copilot guidance for Java backend, React frontend, and Playwright tests.

Context

This repository has the following structure:

• backend/: Java Spring Boot application (Maven-based)
• frontend/: React + Vite application with Material-UI
• tests/: Playwright E2E tests
• docker/: Docker configuration

Reference issue: #24

Tasks

1. Create .github/instructions/ directory structure

Create the directory .github/instructions/ if it doesn't exist.

2. Backend Java Instructions (.github/instructions/backend.instructions.md)

Create a file-based instruction for the Java backend based on the reference: https://github.com/github/awesome-copilot/blob/main/instructions/java.instructions.md

Requirements:

• YAML frontmatter with:
  • name: 'Backend Java Development'
  • description: 'Guidelines for Spring Boot backend development'
  • applyTo: 'backend/**/*.java'
• Reference the source instruction file in a comment at the top
• Adapt the generic Java guidelines for Spring Boot specifics:
  • Emphasize REST API conventions
  • Include Spring Boot annotations best practices
  • Add Spring Data JPA patterns
  • Include actuator and health check guidance
• Document any local customizations clearly

3. Frontend React Instructions (.github/instructions/frontend.instructions.md)

Create a file-based instruction for the React frontend based on the reference: https://github.com/github/awesome-copilot/blob/main/instructions/reactjs.instructions.md

Requirements:

• YAML frontmatter with:
  • name: 'Frontend React Development'
  • description: 'Guidelines for React + Vite + Material-UI development'
  • applyTo: 'frontend/**/*.{jsx,tsx,js,ts}'
• Reference the source instruction file in a comment at the top
• Adapt the generic React guidelines for this project:
  • Vite-specific patterns
  • Material-UI component usage
  • React Query patterns (already used in the project)
  • Theme customization guidelines
• Document any local customizations clearly

4. Test Instructions (.github/instructions/tests.instructions.md)

Create a file-based instruction for Playwright tests

Requirements:

• YAML frontmatter with:
  • name: 'E2E Test Development'
  • description: 'Guidelines for Playwright E2E tests'
  • applyTo: 'tests/**/*.{js,ts}'
• Reference relevant testing best practices from github/awesome-copilot
• Include:
  • Playwright test structure patterns
  • Page Object Model recommendations
  • Test naming conventions
  • Assertions and locator best practices
  • Configuration guidance

5. Documentation

Update or create a COPILOT_INSTRUCTIONS.md file in the root that:

• Lists all file-based instructions
• Explains the pattern-matching approach
• References the source materials from github/awesome-copilot
• Documents any repo-specific customizations

Acceptance Criteria

• Three instruction files created in .github/instructions/
• Each file has proper YAML frontmatter with name, description, and applyTo fields
• Each file clearly references the github/awesome-copilot baseline it's based on
• applyTo patterns are specific and non-overlapping
• Backend instructions cover Spring Boot patterns
• Frontend instructions cover Vite + Material-UI patterns
• Test instructions cover Playwright patterns
• Documentation file explains the instruction structure

References

• File-Based Instructions Guide: https://github.com/Norman-Norman-Norman/customize-your-repo/blob/main/docs/part-2-2-file-based-instructions.md
• Java Instructions Template: https://github.com/github/awesome-copilot/blob/main/instructions/java.instructions.md
• React Instructions Template: https://github.com/github/awesome-copilot/blob/main/instructions/reactjs.instructions.md
• Issue Implement and Track File-Based Instructions for This Repository (with cross-repo references) #24: Implement and Track File-Based Instructions for This Repository (with cross-repo references) #24

This pull request was created from Copilot chat.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.