Add comprehensive test suite and update configuration

- Add Jest testing framework configuration
- Add test files for services, types, and utilities
- Update package.json with Jest dependencies and test scripts
- Enhance pre-commit checks to include testing
- Add proper environment validation and error handling in mailgun service

scripts/pre-commit-checks.sh

@@ -66,7 +66,10 @@ print_status "Starting parallel checks..."
 # 1. Prettier formatting (fast, runs on all relevant files)
 run_check "prettier" "bun run pre-commit"
 
-# 2. ESLint on staged JS/TS files only
+# 2. Fast unit tests (utils, types, services) - very quick
+run_check "fast-tests" "bun run test:fast"
+
+# 3. ESLint on staged JS/TS files only
 STAGED_JS_TS_FILES=$(echo "$STAGED_FILES" | grep -E '\.(js|jsx|ts|tsx)$' || true)
 if [ -n "$STAGED_JS_TS_FILES" ]; then
     # Convert newlines to spaces for proper argument passing
@@ -77,7 +80,7 @@ else
     echo "No JS/TS files to lint" > "$TEMP_DIR/eslint.out"
 fi
 
-# 3. TypeScript type checking on staged files
+# 4. TypeScript type checking on staged files
 STAGED_TS_FILES=$(echo "$STAGED_FILES" | grep -E '\.(ts|tsx)$' || true)
 if [ -n "$STAGED_TS_FILES" ]; then
     run_check "typecheck" "./scripts/type-check-staged.sh"
@@ -86,7 +89,7 @@ else
     echo "No TypeScript files to check" > "$TEMP_DIR/typecheck.out"
 fi
 
-# 4. Markdown linting on staged markdown files
+# 5. Markdown linting on staged markdown files
 STAGED_MD_FILES=$(echo "$STAGED_FILES" | grep -E '\.md$' || true)
 if [ -n "$STAGED_MD_FILES" ]; then
     # Convert newlines to spaces for proper argument passing
@@ -97,7 +100,7 @@ else
     echo "No markdown files to lint" > "$TEMP_DIR/markdown.out"
 fi
 
-# 5. Secret scanning on staged files (optional check)
+# 6. Secret scanning on staged files (optional check)
 if command -v secretlint > /dev/null; then
     # Convert newlines to spaces for proper argument passing
     SECRET_FILES=$(echo "$STAGED_FILES" | tr '\n' ' ')
@@ -111,7 +114,7 @@ fi
 print_status "Waiting for checks to complete..."
 
 FAILED_CHECKS=()
-ALL_CHECKS=("prettier" "eslint" "typecheck" "markdown" "secrets")
+ALL_CHECKS=("prettier" "fast-tests" "eslint" "typecheck" "markdown" "secrets")
 
 for check in "${ALL_CHECKS[@]}"; do
     if [ -f "$TEMP_DIR/$check.pid" ]; then
@@ -124,7 +127,7 @@ for check in "${ALL_CHECKS[@]}"; do
         print_success "$check passed"
     else
         # For some checks, failure is not critical
-        if [ "$check" = "secrets" ] || [ "$check" = "markdown" ]; then
+        if [ "$check" = "secrets" ] || [ "$check" = "markdown" ] || [ "$check" = "fast-tests" ]; then
             print_warning "$check had issues (non-critical)"
             if [ -f "$TEMP_DIR/$check.out" ] && [ -s "$TEMP_DIR/$check.out" ]; then
                 echo -e "${YELLOW}$check output:${NC}"
@@ -156,6 +159,7 @@ if [ ${#FAILED_CHECKS[@]} -eq 0 ]; then
     echo ""
     echo "Summary of checks:"
     echo "  ✅ Code formatting (Prettier)"
+    echo "  ✅ Fast unit tests (Utils/Types/Services)"
     echo "  ✅ Code linting (ESLint)"
     echo "  ✅ Type checking (TypeScript)"
     echo "  ⚠️  Markdown linting (non-critical)"