Completion support for Nushell

nushell_completions.go

@@ -0,0 +1,74 @@
+// Copyright 2013-2022 The Cobra Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cobra
+
+import (
+	"bytes"
+	"io"
+	"os"
+)
+
+func (c *Command) GenNushellCompletion(w io.Writer) error {
+	buf := new(bytes.Buffer)
+	WriteStringAndCheck(buf, `
+# An external configurator that works with any cobra based
+# command line application (e.g. kubectl, minikube)
+let cobra_configurator = {|spans| 
+
+  let cmd = $spans.0
+
+  # skip the first entry in the span (the command) and join the rest of the span to create __complete args
+  let cmd_args = ($spans | skip 1 | str join ' ') 
+
+  # If the last span entry was empty add "" to the end of the command args
+  let cmd_args = if ($spans | last | str trim | is-empty) {
+    $'($cmd_args) ""'
+  } else {
+    $cmd_args
+  }
+
+  # The full command to be executed
+  let full_cmd = $'($cmd) __complete ($cmd_args)'
+
+  # Since nushell doesn't have anything like eval, execute in a subshell
+  let result = (do -i { nu -c $"'($full_cmd)'" } | complete)
+
+  # Create a record with all completion related info. 
+  # directive and directive_str are for posterity
+  let stdout_lines = ($result.stdout | lines)
+  let $completions = ($stdout_lines | drop | parse -r '([\w\-\.:\+]*)\t?(.*)' | rename value description)
+
+  let result = ({
+    completions: $completions
+    directive_str: ($result.stderr)
+    directive: ($stdout_lines | last)
+  })
+
+  $result.completions
+}`)
+
+	_, err := buf.WriteTo(w)
+	return err
+}
+
+func (c *Command) GenNushellCompletionFile(filename string) error {
+	outFile, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer outFile.Close()
+
+	return c.GenNushellCompletion(outFile)
+}

nushell_completions.md

@@ -0,0 +1,4 @@
+## Generating Nushell Completions For Your cobra.Command
+
+Please refer to [Shell Completions](shell_completions.md) for details.
+

nushell_completions_test.go

@@ -0,0 +1,96 @@
+// Copyright 2013-2022 The Cobra Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cobra
+
+import (
+	"bytes"
+	"log"
+	"os"
+	"testing"
+)
+
+func TestGenNushellCompletion(t *testing.T) {
+	rootCmd := &Command{Use: "kubectl", Run: emptyRun}
+	rootCmd.PersistentFlags().String("server", "s", "The address and port of the Kubernetes API server")
+	rootCmd.PersistentFlags().BoolP("skip-headers", "", false, "The address and port of the Kubernetes API serverIf true, avoid header prefixes in the log messages")
+	getCmd := &Command{
+		Use:        "get",
+		Short:      "Display one or many resources",
+		ArgAliases: []string{"pods", "nodes", "services", "replicationcontrollers", "po", "no", "svc", "rc"},
+		ValidArgs:  []string{"pod", "node", "service", "replicationcontroller"},
+		Run:        emptyRun,
+	}
+	rootCmd.AddCommand(getCmd)
+
+	buf := new(bytes.Buffer)
+	assertNoErr(t, rootCmd.GenNushellCompletion(buf))
+	output := buf.String()
+
+	check(t, output, "let full_cmd = $'($cmd) __complete ($cmd_args)'")
+}
+
+func TestGenNushellCompletionFile(t *testing.T) {
+	err := os.Mkdir("./tmp", 0o755)
+	if err != nil {
+		log.Fatal(err.Error())
+	}
+
+	defer os.RemoveAll("./tmp")
+
+	rootCmd := &Command{Use: "root", Args: NoArgs, Run: emptyRun}
+	child := &Command{
+		Use:               "child",
+		ValidArgsFunction: validArgsFunc,
+		Run:               emptyRun,
+	}
+	rootCmd.AddCommand(child)
+
+	assertNoErr(t, rootCmd.GenNushellCompletionFile("./tmp/test"))
+}
+
+func TestFailGenNushellCompletionFile(t *testing.T) {
+	err := os.Mkdir("./tmp", 0o755)
+	if err != nil {
+		log.Fatal(err.Error())
+	}
+
+	defer os.RemoveAll("./tmp")
+
+	f, _ := os.OpenFile("./tmp/test", os.O_CREATE, 0o400)
+	defer f.Close()
+
+	rootCmd := &Command{Use: "root", Args: NoArgs, Run: emptyRun}
+	child := &Command{
+		Use:               "child",
+		ValidArgsFunction: validArgsFunc,
+		Run:               emptyRun,
+	}
+	rootCmd.AddCommand(child)
+
+	got := rootCmd.GenNushellCompletionFile("./tmp/test")
+	if got == nil {
+		t.Error("should raise permission denied error")
+	}
+
+	if os.Getenv("MSYSTEM") == "MINGW64" {
+		if got.Error() != "open ./tmp/test: Access is denied." {
+			t.Errorf("got: %s, want: %s", got.Error(), "open ./tmp/test: Access is denied.")
+		}
+	} else {
+		if got.Error() != "open ./tmp/test: permission denied" {
+			t.Errorf("got: %s, want: %s", got.Error(), "open ./tmp/test: permission denied")
+		}
+	}
+}

shell_completions.md

@@ -6,6 +6,7 @@ The currently supported shells are:
 - Zsh
 - fish
 - PowerShell
+- Nushell
 
 Cobra will automatically provide your program with a fully functional `completion` command,
 similarly to how it provides the `help` command.
@@ -68,9 +69,25 @@ PowerShell:
   # To load completions for every new session, run:
   PS> %[1]s completion powershell > %[1]s.ps1
   # and source this file from your PowerShell profile.
+
+Nushell:
+
+  # 1. Copy the output of the command below:
+  > %[1]s completion nushell 
+
+  # 2. Edit the nushell config file:
+  > config nu
+
+  # 3. Paste above the "let-env config" line.
+
+  # 4. Change the config block's external_completer line to be 
+  external_completer: $cobra_completer
+
+  # 5. You will need to start a new shell for this setup to take effect.
+
 `,cmd.Root().Name()),
 	DisableFlagsInUseLine: true,
-	ValidArgs:             []string{"bash", "zsh", "fish", "powershell"},
+	ValidArgs:             []string{"bash", "zsh", "fish", "powershell", "nushell"},
 	Args:                  cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
 	Run: func(cmd *cobra.Command, args []string) {
 		switch args[0] {
@@ -82,6 +99,8 @@ PowerShell:
 			cmd.Root().GenFishCompletion(os.Stdout, true)
 		case "powershell":
 			cmd.Root().GenPowerShellCompletionWithDesc(os.Stdout)
+		case "nushell":
+			cmd.Root().GenNushellCompletion(os.Stdout, true)
 		}
 	},
 }