fix: help flags preprocessing for -h and -help (#707)

Author: dlevy-msft-sql

cmd/sqlcmd/sqlcmd.go

@@ -295,6 +295,8 @@ func Execute(version string) {
 // We need to rewrite the arguments to add -i and -v in front of each space-delimited value to be Cobra-friendly.
 // For flags like -r we need to inject the default value if the user omits it
 func convertOsArgs(args []string) (cargs []string) {
+	args = preprocessHelpFlags(args)
+
 	flag := ""
 	first := true
 	for i, a := range args {
@@ -324,6 +326,31 @@ func convertOsArgs(args []string) (cargs []string) {
 	return
 }
 
+// preprocessHelpFlags converts -h (without number) and -help to help flags.
+// -h with a number is left alone for header count backward compatibility.
+func preprocessHelpFlags(args []string) []string {
+	result := make([]string, 0, len(args))
+	for i := 0; i < len(args); i++ {
+		arg := args[i]
+		if arg == "-help" {
+			result = append(result, "--help")
+			continue
+		}
+		if arg == "-h" {
+			if i+1 < len(args) {
+				if _, err := strconv.Atoi(args[i+1]); err == nil {
+					result = append(result, arg) // -h <number> for headers
+					continue
+				}
+			}
+			result = append(result, "-?")
+			continue
+		}
+		result = append(result, arg)
+	}
+	return result
+}
+
 // If args[i] is the given flag and args[i+1] is another flag, returns the value to append after the flag
 func checkDefaultValue(args []string, i int) (val string) {
 	flags := map[rune]string{

cmd/sqlcmd/sqlcmd_test.go

@@ -593,6 +593,30 @@ func TestConvertOsArgs(t *testing.T) {
 	}
 }
 
+func TestPreprocessHelpFlags(t *testing.T) {
+	type test struct {
+		name     string
+		in       []string
+		expected []string
+	}
+
+	tests := []test{
+		{"empty args", []string{}, []string{}},
+		{"-help to --help", []string{"-help"}, []string{"--help"}},
+		{"-h alone to -?", []string{"-h"}, []string{"-?"}},
+		{"-h with number stays", []string{"-h", "5"}, []string{"-h", "5"}},
+		{"-h with flag becomes -?", []string{"-h", "-S"}, []string{"-?", "-S"}},
+		{"mixed args", []string{"-S", "server", "-h", "-Q", "select 1"}, []string{"-S", "server", "-?", "-Q", "select 1"}},
+		{"preserve -h N in context", []string{"-S", "srv", "-h", "10", "-Q", "x"}, []string{"-S", "srv", "-h", "10", "-Q", "x"}},
+	}
+	for _, c := range tests {
+		t.Run(c.name, func(t *testing.T) {
+			actual := preprocessHelpFlags(c.in)
+			assert.Equal(t, c.expected, actual, "Incorrect preprocessed args")
+		})
+	}
+}
+
 func TestEncryptionOptions(t *testing.T) {
 	type test struct {
 		input  string