Fix substitution of quoted variables

testcli.go failed before the fix and passes after it.
Also includes a fix to testcli.go itself.

stmt/stmt.go

@@ -228,6 +228,7 @@ parse:
 				z, ok, _ := unquote(v.Name, true)
 				if v.Defined = ok || v.Quote == '?'; v.Defined {
 					b.r, b.rlen = v.Substitute(b.r, z, ok)
+					i-- // account for removal of the :
 				}
 				if b.Len != 0 {
 					v.I += b.Len + 1

testcli.go

@@ -12,6 +12,7 @@ import (
 	"log"
 	"os"
 	"regexp"
+	"strings"
 	"time"
 
 	gexpect "github.com/google/goexpect"
@@ -127,9 +128,17 @@ func (test Test) do(ctx context.Context, binpath string, timeout time.Duration)
 		return err
 	}
 	for _, line := range bytes.Split(buf, []byte{'\n'}) {
+		// give time to usql to react to sent commands so statements are close to their results in output
+		// this helps link failures to the statement that caused them
+		time.Sleep(100 * time.Millisecond)
 		if err := exp.Send(string(line) + "\n"); err != nil {
 			return err
 		}
+		if strings.TrimSpace(string(line)) == "\\q" {
+			break
+			// don't send any lines after quit command e.g. trailing empty lines
+			// Send() fails if the command has stopped
+		}
 	}
 	select {
 	case <-ctx.Done():