Shell completions never ask for a login (fixes brew install)

cmd/completion_test.go

@@ -0,0 +1,58 @@
+package cmd
+
+import (
+	"context"
+	"io"
+	"path/filepath"
+	"testing"
+
+	"github.com/spf13/cobra"
+)
+
+// TestCompletionNeedsNoLogin runs the shell completion generator the way
+// Homebrew does at install time: no token anywhere, no config file yet.
+// Cobra binds the generator's writer on the first execution in a process,
+// so the script itself is not captured here; the refusal is what matters.
+func TestCompletionNeedsNoLogin(t *testing.T) {
+	t.Setenv("TAEL_CONFIG", filepath.Join(t.TempDir(), "tael.yaml"))
+	t.Setenv(envAPIToken, "")
+	t.Setenv(envBaseURL, "")
+	t.Setenv(envWorkspace, "")
+	resetFlags(rootCmd)
+
+	rootCmd.SetOut(io.Discard)
+	rootCmd.SetErr(io.Discard)
+	rootCmd.SetArgs([]string{"completion", "zsh"})
+	t.Cleanup(func() {
+		resetFlags(rootCmd)
+		rootCmd.SetOut(nil)
+		rootCmd.SetErr(nil)
+		rootCmd.SetArgs(nil)
+	})
+	if _, executeError := rootCmd.ExecuteContextC(context.Background()); executeError != nil {
+		t.Fatalf("tael completion zsh must not need a login, got: %v", executeError)
+	}
+}
+
+// TestCommandRequiresAuthExemptsOnlyTheRootCompletion pins the rule: the
+// `completion` command directly under the root and its shells are exempt;
+// a command that merely happens to be called completion elsewhere is not.
+func TestCommandRequiresAuthExemptsOnlyTheRootCompletion(t *testing.T) {
+	root := &cobra.Command{Use: "tael"}
+	completion := &cobra.Command{Use: "completion"}
+	zsh := &cobra.Command{Use: "zsh"}
+	root.AddCommand(completion)
+	completion.AddCommand(zsh)
+
+	apps := &cobra.Command{Use: "apps"}
+	nested := &cobra.Command{Use: "completion"}
+	root.AddCommand(apps)
+	apps.AddCommand(nested)
+
+	if commandRequiresAuth(completion) || commandRequiresAuth(zsh) {
+		t.Fatal("completion and its shells must not require a login")
+	}
+	if !commandRequiresAuth(apps) || !commandRequiresAuth(nested) {
+		t.Fatal("every other command still requires a login")
+	}
+}

cmd/root.go

@@ -156,6 +156,9 @@ func commandRequiresAuth(command *cobra.Command) bool {
 	case "help", cobra.ShellCompRequestCmd, cobra.ShellCompNoDescRequestCmd:
 		return false
 	}
+	if isShellCompletionCommand(command) {
+		return false
+	}
 	for current := command; current != nil; current = current.Parent() {
 		if current.Annotations == nil {
 			continue
@@ -166,3 +169,16 @@ func commandRequiresAuth(command *cobra.Command) bool {
 	}
 	return true
 }
+
+// isShellCompletionCommand reports whether the command is cobra's
+// `completion <shell>` generator or one of its shells. Cobra adds it at
+// execution time, so it cannot carry the annotation; Homebrew runs it while
+// installing, before anyone has logged in.
+func isShellCompletionCommand(command *cobra.Command) bool {
+	for current := command; current != nil; current = current.Parent() {
+		if current.Name() == "completion" && current.HasParent() && !current.Parent().HasParent() {
+			return true
+		}
+	}
+	return false
+}