Ensure pty and terminal size matches

termtest.go

@@ -31,8 +31,8 @@ type ErrorHandler func(*TermTest, error) error
 type Opts struct {
 	Logger             *log.Logger
 	ExpectErrorHandler ErrorHandler
-	Cols               uint16
-	Rows               uint16
+	Cols               int
+	Rows               int
 	Posix              bool
 	DefaultTimeout     time.Duration
 }
@@ -126,7 +126,7 @@ func OptTestErrorHandler(t *testing.T) SetOpt {
 	return OptErrorHandler(TestErrorHandler(t))
 }
 
-func OptCols(cols uint16) SetOpt {
+func OptCols(cols int) SetOpt {
 	return func(o *Opts) error {
 		o.Cols = cols
 		return nil
@@ -135,7 +135,7 @@ func OptCols(cols uint16) SetOpt {
 
 // OptRows sets the number of rows for the pty, increase this if you find your output appears to stop prematurely
 // appears to only make a difference on Windows. Linux/Mac will happily function with a single row
-func OptRows(rows uint16) SetOpt {
+func OptRows(rows int) SetOpt {
 	return func(o *Opts) error {
 		o.Rows = rows
 		return nil
@@ -181,13 +181,14 @@ func (tt *TermTest) start() error {
 		return fmt.Errorf("already started")
 	}
 
-	ptmx, err := pty.StartWithSize(tt.cmd, &pty.Winsize{Cols: tt.opts.Cols, Rows: tt.opts.Rows})
+	ptmx, err := pty.StartWithSize(tt.cmd, &pty.Winsize{Cols: uint16(tt.opts.Cols), Rows: uint16(tt.opts.Rows)})
 	if err != nil {
 		return fmt.Errorf("could not start pty: %w", err)
 	}
 	tt.ptmx = ptmx
 
 	tt.term = vt10x.New(vt10x.WithWriter(ptmx))
+	tt.term.Resize(tt.opts.Cols, tt.opts.Rows)
 
 	// Start listening for output
 	wg := &sync.WaitGroup{}

termtest_test.go

@@ -3,6 +3,7 @@ package termtest
 import (
 	"fmt"
 	"os/exec"
+	"runtime"
 	"strings"
 	"sync"
 	"testing"
@@ -105,8 +106,8 @@ func Test_ExpectExitCode(t *testing.T) {
 }
 
 func Test_SendAndOutput(t *testing.T) {
-	var cols uint16 = 20
-	strColWidth := strings.Repeat("o", int(cols))
+	var cols int = 20
+	strColWidth := strings.Repeat("o", cols)
 	tests := []struct {
 		name     string
 		termtest func(t *testing.T) *TermTest
@@ -181,3 +182,20 @@ func Test_PendingOutput_Output_Snapshot(t *testing.T) {
 	assert.Equal(t, "MATCH1 MATCH2 MATCH3", strings.TrimRight(tt.Output(), "\r\n"))
 	assert.Contains(t, strings.TrimRight(tt.Snapshot(), "\r\n"), "MATCH1 MATCH2 MATCH3")
 }
+
+func Test_ColSize(t *testing.T) {
+	size := 1000
+	shell := "bash"
+	if runtime.GOOS == "windows" {
+		shell = "cmd.exe"
+	}
+	tt := newTermTest(t, exec.Command(shell), true, OptCols(size))
+	v := strings.Repeat("a", size)
+	tt.SendLine("echo " + v)
+	tt.Expect(v)
+	tt.SendLine("exit")
+	tt.ExpectExitCode(0)
+
+	// Also test that the terminal snapshot has the right col size
+	require.Contains(t, tt.Snapshot(), v)
+}