SQL Server GO batch splitter in Go — line-by-line, case-insensitive, dodges the 'GOPHER' trap

split-go-batches.go

// split-go-batches.go — line-by-line GO batch splitter for SQL Server clients.
//
// GO is not a SQL Server keyword. It's a client convention. If you write your
// own SQL Server tooling (like I did with a Go-based DBA diagnostic agent),
// you need to split on GO before sending each batch over TDS. The naive regex
// on substring "GO" breaks on strings like 'GOPHER'. This version matches GO
// only when it's on its own line, case-insensitive, with whitespace trimmed.
//
// Written up in: https://www.linkedin.com/in/fernando-possebon
//
// Test cases that justify the exact-match approach:
//   - Input containing `SELECT 'GOPHER' AS animal` — must NOT split
//   - Input with `go`, `Go`, and `GO` on their own lines — must all split
//   - Input with trailing `GO  ` (trailing whitespace) — must split
package main

import "strings"

func splitGoBatches(input string) []string {
	lines := strings.Split(input, "\n")
	var batches []string
	var current []string

	for _, line := range lines {
		trimmed := strings.TrimSpace(line)
		if strings.EqualFold(trimmed, "GO") {
			batch := strings.TrimSpace(strings.Join(current, "\n"))
			if batch != "" {
				batches = append(batches, batch)
			}
			current = nil
			continue
		}
		current = append(current, line)
	}

	if last := strings.TrimSpace(strings.Join(current, "\n")); last != "" {
		batches = append(batches, last)
	}
	return batches
}