command: parameter autocomplete for "terraform workspace ..."

Shell tab completion for all of the subcommands under
"terraform workspace", providing the appropriate kind of auto-complete for
each argument, along with completion for for any flags.

command/workspace_delete.go

@@ -8,6 +8,7 @@ import (
 	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/state"
 	"github.com/mitchellh/cli"
+	"github.com/posener/complete"
 )
 
 type WorkspaceDeleteCommand struct {
@@ -156,6 +157,21 @@ func (c *WorkspaceDeleteCommand) Run(args []string) int {
 
 	return 0
 }
+
+func (c *WorkspaceDeleteCommand) AutocompleteArgs() complete.Predictor {
+	return completePredictSequence{
+		complete.PredictNothing, // the "select" subcommand itself (already matched)
+		c.completePredictWorkspaceName(),
+		complete.PredictDirs(""),
+	}
+}
+
+func (c *WorkspaceDeleteCommand) AutocompleteFlags() complete.Flags {
+	return complete.Flags{
+		"-force": complete.PredictNothing,
+	}
+}
+
 func (c *WorkspaceDeleteCommand) Help() string {
 	helpText := `
 Usage: terraform workspace delete [OPTIONS] NAME [DIR]

command/workspace_list.go

@@ -4,6 +4,8 @@ import (
 	"bytes"
 	"fmt"
 	"strings"
+
+	"github.com/posener/complete"
 )
 
 type WorkspaceListCommand struct {
@@ -75,6 +77,14 @@ func (c *WorkspaceListCommand) Run(args []string) int {
 	return 0
 }
 
+func (c *WorkspaceListCommand) AutocompleteArgs() complete.Predictor {
+	return complete.PredictDirs("")
+}
+
+func (c *WorkspaceListCommand) AutocompleteFlags() complete.Flags {
+	return nil
+}
+
 func (c *WorkspaceListCommand) Help() string {
 	helpText := `
 Usage: terraform workspace list [DIR]

command/workspace_new.go

@@ -10,6 +10,7 @@ import (
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/cli"
+	"github.com/posener/complete"
 )
 
 type WorkspaceNewCommand struct {
@@ -156,6 +157,20 @@ func (c *WorkspaceNewCommand) Run(args []string) int {
 	return 0
 }
 
+func (c *WorkspaceNewCommand) AutocompleteArgs() complete.Predictor {
+	return completePredictSequence{
+		complete.PredictNothing, // the "new" subcommand itself (already matched)
+		complete.PredictAnything,
+		complete.PredictDirs(""),
+	}
+}
+
+func (c *WorkspaceNewCommand) AutocompleteFlags() complete.Flags {
+	return complete.Flags{
+		"-state": complete.PredictFiles("*.tfstate"),
+	}
+}
+
 func (c *WorkspaceNewCommand) Help() string {
 	helpText := `
 Usage: terraform workspace new [OPTIONS] NAME [DIR]

command/workspace_select.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/mitchellh/cli"
+	"github.com/posener/complete"
 )
 
 type WorkspaceSelectCommand struct {
@@ -103,6 +104,18 @@ func (c *WorkspaceSelectCommand) Run(args []string) int {
 	return 0
 }
 
+func (c *WorkspaceSelectCommand) AutocompleteArgs() complete.Predictor {
+	return completePredictSequence{
+		complete.PredictNothing, // the "select" subcommand itself (already matched)
+		c.completePredictWorkspaceName(),
+		complete.PredictDirs(""),
+	}
+}
+
+func (c *WorkspaceSelectCommand) AutocompleteFlags() complete.Flags {
+	return nil
+}
+
 func (c *WorkspaceSelectCommand) Help() string {
 	helpText := `
 Usage: terraform workspace select NAME [DIR]

command/workspace_show.go

@@ -2,6 +2,8 @@ package command
 
 import (
 	"strings"
+
+	"github.com/posener/complete"
 )
 
 type WorkspaceShowCommand struct {
@@ -26,6 +28,14 @@ func (c *WorkspaceShowCommand) Run(args []string) int {
 	return 0
 }
 
+func (c *WorkspaceShowCommand) AutocompleteArgs() complete.Predictor {
+	return complete.PredictNothing
+}
+
+func (c *WorkspaceShowCommand) AutocompleteFlags() complete.Flags {
+	return nil
+}
+
 func (c *WorkspaceShowCommand) Help() string {
 	helpText := `
 Usage: terraform workspace show