feat: add fish and zsh completion support (#207)

Signed-off-by: Rui Chen <[email protected]>

internal/commands/completion/completion.go

@@ -23,9 +23,11 @@ import (
 
 var Command = &cli.Command{
 	Name:  "completion",
-	Usage: "Output shell completion code for bash and powershell",
+	Usage: "Output shell completion code for bash, zsh, fish, and powershell",
 	Subcommands: []*cli.Command{
 		bashCommand,
+		fishCommand,
+		zshCommand,
 		powershellCommand,
 	},
 }

internal/commands/completion/fish.go

@@ -0,0 +1,55 @@
+// Licensed to Apache Software Foundation (ASF) under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Apache Software Foundation (ASF) licenses this file to you 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 completion
+
+import (
+	"fmt"
+
+	"github.com/urfave/cli/v2"
+)
+
+var fishCommand = &cli.Command{
+	Name:      "fish",
+	Aliases:   []string{"f"},
+	Usage:     "Output shell completion code for fish",
+	ArgsUsage: "[parameters...]",
+	Action: func(ctx *cli.Context) error {
+		fmt.Print(fishScript)
+		return nil
+	},
+}
+
+const fishScript = `
+function __fish_swctl_complete
+    set -l command (commandline -cp)
+    set -l last_token (commandline -ct)
+
+    if test "$last_token" = ""
+        return
+    end
+
+    # Get completions using the auto-complete flag
+    set -l completions (eval "$command --auto_complete" 2> /dev/null)
+
+    for completion in $completions
+        echo -e "$completion\t(swctl suggestion)"
+    end
+end
+
+complete -c swctl -f -a "(__fish_swctl_complete)"
+`

internal/commands/completion/zsh.go

@@ -0,0 +1,51 @@
+// Licensed to Apache Software Foundation (ASF) under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Apache Software Foundation (ASF) licenses this file to you 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 completion
+
+import (
+	"fmt"
+
+	"github.com/urfave/cli/v2"
+)
+
+var zshCommand = &cli.Command{
+	Name:      "zsh",
+	Aliases:   []string{"z"},
+	Usage:     "Output shell completion code for zsh",
+	ArgsUsage: "[parameters...]",
+	Action: func(ctx *cli.Context) error {
+		fmt.Print(zshScript)
+		return nil
+	},
+}
+
+const zshScript = `
+#compdef swctl
+
+_cli_zsh_autocomplete() {
+    local -a completions
+    local word
+
+    word="${words[CURRENT]}"
+    completions=("${(@f)$( ${words[1,CURRENT-1]} --auto_complete )}")
+
+    _describe -t commands 'swctl commands' completions
+}
+
+compdef _cli_zsh_autocomplete swctl
+`