Function normalizePostgreSQLCheckConstraint

backend/plugin/schema/differ.go:2272–2333

normalizePostgreSQLCheckConstraint normalizes PostgreSQL check constraint expressions for comparison

(expression string)

// normalizePostgreSQLCheckConstraint normalizes PostgreSQL check constraint expressions for comparison
func normalizePostgreSQLCheckConstraint(expression string) string {
	// Based on the test output, we need to normalize:
	// Sync: (order_date >= (CURRENT_DATE - '1 year'::interval))
	// Parser: order_date >= CURRENT_DATE - INTERVAL '1 year'
	// Both should normalize to the same canonical form

	expression = strings.TrimSpace(expression)

	// Step 1: Remove outer parentheses
	for strings.HasPrefix(expression, "(") && strings.HasSuffix(expression, ")") {
		// Only remove if they are balanced and wrapping the entire expression
		inner := expression[1 : len(expression)-1]
		parenCount := 0
		canRemove := true
		for _, ch := range inner {
			if ch == '(' {
				parenCount++
			} else if ch == ')' {
				parenCount--
				if parenCount < 0 {
					canRemove = false
					break
				}
			}
		}
		if canRemove && parenCount == 0 {
			expression = inner
		} else {
			break
		}
	}

	// Step 2: Normalize interval syntax
	// Convert ::interval to INTERVAL prefix
	expression = strings.ReplaceAll(expression, "'::interval", "'")

	// Step 3: Standardize to INTERVAL syntax
	if strings.Contains(expression, "CURRENT_DATE") && strings.Contains(expression, "'") && !strings.Contains(expression, "INTERVAL") {
		// Add INTERVAL prefix where needed
		expression = strings.ReplaceAll(expression, "CURRENT_DATE - '", "CURRENT_DATE - INTERVAL '")
		expression = strings.ReplaceAll(expression, "CURRENT_DATE + '", "CURRENT_DATE + INTERVAL '")
	}

	// Step 4: Remove extra parentheses around date arithmetic
	expression = strings.ReplaceAll(expression, "(CURRENT_DATE - INTERVAL", "CURRENT_DATE - INTERVAL")
	expression = strings.ReplaceAll(expression, "(CURRENT_DATE + INTERVAL", "CURRENT_DATE + INTERVAL")

	// Step 5: Clean up trailing parentheses after year'
	if strings.Contains(expression, "year'") && strings.Contains(expression, "INTERVAL") {
		expression = strings.ReplaceAll(expression, "year')", "year'")
	}

	// Step 6: Normalize timestamp literals and type casts
	// '2020-01-01 00:00:00'::timestamp without time zone -> '2020-01-01'::timestamp
	expression = strings.ReplaceAll(expression, " 00:00:00'::timestamp without time zone", "'::timestamp")

	// Step 7: Normalize numeric type casts
	// >= 0::numeric -> >= 0