Adds completion command

cmd/completion.go

@@ -0,0 +1,73 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+func CompletionCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "completion",
+		Short: "Generates autocompletions for bash and zsh",
+	}
+
+	cmd.AddCommand(
+		BashCompletionCmd(),
+		ZshCompletionCmd(),
+	)
+
+	return cmd
+}
+
+func BashCompletionCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "bash",
+		Short: "Generates autocompletions for bash",
+		Long: `Generates autocompletions for bash. To load them, run:
+
+. <(campaigner completion bash)
+
+To configure your bash shell to load completions for each session, add the above line to your ~/.bashrc`,
+		Run: bashCompletionCmdF,
+	}
+}
+
+func ZshCompletionCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "zsh",
+		Short: "Generates autocompletions for zsh",
+		Long: `Generates autocompletions for zsh. To load them, run:
+
+. <(campaigner completion zsh)
+
+To configure your zsh shell to load completions for each session, add the above line to your ~/.zshrc`,
+		Run: zshCompletionCmdF,
+	}
+}
+
+func getRoot(cmd *cobra.Command) *cobra.Command {
+	root := cmd
+	for {
+		if !root.HasParent() {
+			break
+		}
+		root = root.Parent()
+	}
+	return root
+}
+
+func bashCompletionCmdF(cmd *cobra.Command, args []string) {
+	root := getRoot(cmd)
+	if err := root.GenBashCompletion(os.Stdout); err != nil {
+		ErrorAndExit(cmd, fmt.Errorf("unable to generate completions: %w", err))
+	}
+}
+
+func zshCompletionCmdF(cmd *cobra.Command, args []string) {
+	root := getRoot(cmd)
+	if err := root.GenZshCompletion(os.Stdout); err != nil {
+		ErrorAndExit(cmd, fmt.Errorf("unable to generate completions: %w", err))
+	}
+}

cmd/root.go

@@ -53,6 +53,7 @@ func RootCmd() *cobra.Command {
 		PullCmd(),
 		SyncCmd(),
 		ReportCmd(),
+		CompletionCmd(),
 	)
 
 	return cmd