Decode contents by default in workspace export command (#531)

## Changes

Also see #525.

The direct download flag has been removed in newer versions because of
the content type issue.

Instead, we can make the command decode the base64 output when the
output mode is text.

```
$ databricks workspace export /some/path/script.sh
#!/bin/bash
echo "this is a script"
```

## Tests

New integration test.

cmd/workspace/workspace/overrides.go

@@ -8,4 +8,7 @@ func init() {
 	{{header "ID"}}	{{header "Type"}}	{{header "Language"}}	{{header "Path"}}
 	{{range .}}{{green "%d" .ObjectId}}	{{blue "%s" .ObjectType}}	{{cyan "%s" .Language}}	{{.Path|cyan}}
 	{{end}}`)
+
+	// The export command prints the contents of the file to stdout by default.
+	exportCmd.Annotations["template"] = `{{.Content | b64_decode}}`
 }

internal/workspace_test.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"path"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -39,6 +40,26 @@ func TestWorkpaceGetStatusErrorWhenNoArguments(t *testing.T) {
 	assert.Equal(t, "accepts 1 arg(s), received 0", err.Error())
 }
 
+func TestWorkpaceExportPrintsContents(t *testing.T) {
+	t.Log(GetEnvOrSkipTest(t, "CLOUD_ENV"))
+
+	ctx := context.Background()
+	w := databricks.Must(databricks.NewWorkspaceClient())
+	tmpdir := temporaryWorkspaceDir(t, w)
+	f, err := filer.NewWorkspaceFilesClient(w, tmpdir)
+	require.NoError(t, err)
+
+	// Write file to workspace
+	contents := "#!/usr/bin/bash\necho hello, world\n"
+	err = f.Write(ctx, "file-a", strings.NewReader(contents))
+	require.NoError(t, err)
+
+	// Run export
+	stdout, stderr := RequireSuccessfulRun(t, "workspace", "export", path.Join(tmpdir, "file-a"))
+	assert.Equal(t, contents, stdout.String())
+	assert.Equal(t, "", stderr.String())
+}
+
 func setupWorkspaceImportExportTest(t *testing.T) (context.Context, filer.Filer, string) {
 	t.Log(GetEnvOrSkipTest(t, "CLOUD_ENV"))
 

libs/cmdio/render.go

@@ -1,6 +1,8 @@
 package cmdio
 
 import (
+	"bytes"
+	"encoding/base64"
 	"encoding/json"
 	"io"
 	"strings"
@@ -93,6 +95,27 @@ func renderTemplate(w io.Writer, tmpl string, v any) error {
 		"pretty_date": func(t time.Time) string {
 			return t.Format("2006-01-02T15:04:05Z")
 		},
+		"b64_encode": func(in string) (string, error) {
+			var out bytes.Buffer
+			enc := base64.NewEncoder(base64.StdEncoding, &out)
+			_, err := enc.Write([]byte(in))
+			if err != nil {
+				return "", err
+			}
+			err = enc.Close()
+			if err != nil {
+				return "", err
+			}
+			return out.String(), nil
+		},
+		"b64_decode": func(in string) (string, error) {
+			dec := base64.NewDecoder(base64.StdEncoding, strings.NewReader(in))
+			out, err := io.ReadAll(dec)
+			if err != nil {
+				return "", err
+			}
+			return string(out), nil
+		},
 	}).Parse(tmpl)
 	if err != nil {
 		return err