feat: add coding style guidelines and testing guidelines to copilot instructions

Signed-off-by: Vladislav Polyakov <[email protected]>

Author: polRk

.github/copilot-instructions.md

@@ -0,0 +1,34 @@
+# Coding Style Guidelines
+
+## Variable Declarations
+
+- Always use `let` instead of `const` for variable declarations, even if the variable is not reassigned
+- This applies to all JavaScript and TypeScript code
+
+## Code Formatting
+
+- Use tabs for indentation (tabWidth: 4)
+- Use single quotes for strings
+- No semicolons at the end of statements (semi: false)
+- Maximum line length: 120 characters
+- Use trailing comma in ES5 style
+- Include spaces inside curly braces (bracketSpacing: true)
+
+## TypeScript Preferences
+
+- Use `#` prefix for private fields
+- Prefer explicit types when possible
+
+## JSON Preferences
+
+- Use double quotes for keys and string values
+- No trailing commas
+- Always include whitespace after colons
+
+# Testing Guidelines
+
+- Write tests for all new features and bug fixes
+- Use a vitest testing framework
+- Aim for high test coverage, but prioritize critical paths
+- Include both unit tests and integration tests
+- Use concise and clear test names that reflect the behavior being tested

.vscode/settings.json

@@ -10,4 +10,5 @@
     },
     "vitest.rootConfig": "./vitest.config.ts",
     "vitest.workspaceConfig": "./vitest.config.ts",
+    "github.copilot.chat.codeGeneration.useInstructionFiles": true
 }