fix: Run expect tests on Windows with conpty pseudo-terminal (#276)

This brings together a bunch of random, partially implemented packages for support of the new(ish) Windows [`conpty`](https://devblogs.microsoft.com/commandline/windows-command-line-introducing-the-windows-pseudo-console-conpty/) API - such that we can leverage the `expect` style of CLI tests, but in a way that works in Linux/OSX `pty`s and Windows `conpty`.

These include:
- Vendoring the `go-expect` library from Netflix w/ some tweaks to work cross-platform
- Vendoring the `pty` cross-platform implementation from [waypoint-plugin-sdk](https://github.com/hashicorp/waypoint-plugin-sdk/tree/b55c787a65ff9b7d2b32cfae80681b78f8f2275e/internal/pkg/pty)
- Vendoring the `conpty` Windows-specific implementation from [waypoint-plugin-sdk](https://github.com/hashicorp/waypoint-plugin-sdk/tree/b55c787a65ff9b7d2b32cfae80681b78f8f2275e/internal/pkg/conpty)
- Adjusting the `pty` interface to work with `go-expect` + the cross-plat version

There were several limitations with the current packages:
- `go-expect` requires the same `os.File` (TTY) for input / output, but `conhost` requires separate file handles
- `conpty` does not handle input, only output
- The cross-platform `pty` didn't expose the full set of primitives needed for `console`

Therefore, the following changes were made:
- Handling of `stdin` was added to the `conpty` interface
- We weren't using the full extent of the `go-expect` interface, so some portions were removed (ie, exec'ing a process) to simplify our implementation and make it easier to extend cross-platform
- Instead of `console` exposing just a `Tty`, it exposes an `InTty` and `OutTty`, to help encapsulate the difference on Windows (on Linux, these point to the same pipe)

Future improvements:
- The `isatty` implementation doesn't support accurate detection of `conhost` pty's without an associated process. In lieu of a more robust check, I've added a `--force-tty` flag intended for test case use - that forces the CLI to run in tty mode.
- It seems the windows implementation doesn't support setting a deadline. This is needed for the expect.Timeout API, but isn't used by us yet.

Fixes #241

cli/clitest/clitest.go

@@ -2,16 +2,13 @@ package clitest
 
 import (
 	"archive/tar"
-	"bufio"
 	"bytes"
 	"errors"
 	"io"
 	"os"
 	"path/filepath"
-	"regexp"
 	"testing"
 
-	"github.com/Netflix/go-expect"
 	"github.com/spf13/cobra"
 	"github.com/stretchr/testify/require"
 
@@ -21,12 +18,6 @@ import (
 	"github.com/coder/coder/provisioner/echo"
 )
 
-var (
-	// Used to ensure terminal output doesn't have anything crazy!
-	// See: https://stackoverflow.com/a/29497680
-	stripAnsi = regexp.MustCompile("[\u001B\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\u0007)|(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))")
-)
-
 // New creates a CLI instance with a configuration pointed to a
 // temporary testing directory.
 func New(t *testing.T, args ...string) (*cobra.Command, config.Root) {
@@ -55,31 +46,6 @@ func CreateProjectVersionSource(t *testing.T, responses *echo.Responses) string
 	return directory
 }
 
-// NewConsole creates a new TTY bound to the command provided.
-// All ANSI escape codes are stripped to provide clean output.
-func NewConsole(t *testing.T, cmd *cobra.Command) *expect.Console {
-	reader, writer := io.Pipe()
-	scanner := bufio.NewScanner(reader)
-	t.Cleanup(func() {
-		_ = reader.Close()
-		_ = writer.Close()
-	})
-	go func() {
-		for scanner.Scan() {
-			if scanner.Err() != nil {
-				return
-			}
-			t.Log(stripAnsi.ReplaceAllString(scanner.Text(), ""))
-		}
-	}()
-
-	console, err := expect.NewConsole(expect.WithStdout(writer))
-	require.NoError(t, err)
-	cmd.SetIn(console.Tty())
-	cmd.SetOut(console.Tty())
-	return console
-}
-
 func extractTar(t *testing.T, data []byte, directory string) {
 	reader := tar.NewReader(bytes.NewBuffer(data))
 	for {

cli/clitest/clitest_test.go

@@ -1,5 +1,3 @@
-//go:build !windows
-
 package clitest_test
 
 import (
@@ -7,6 +5,7 @@ import (
 
 	"github.com/coder/coder/cli/clitest"
 	"github.com/coder/coder/coderd/coderdtest"
+	"github.com/coder/coder/expect"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/goleak"
 )
@@ -21,7 +20,7 @@ func TestCli(t *testing.T) {
 	client := coderdtest.New(t)
 	cmd, config := clitest.New(t)
 	clitest.SetupConfig(t, client, config)
-	console := clitest.NewConsole(t, cmd)
+	console := expect.NewTestConsole(t, cmd)
 	go func() {
 		err := cmd.Execute()
 		require.NoError(t, err)