chore: change cli error message handling (#9952)

* chore: add command to easily visualize different errors

* chore: add verbose error printing in cli

cli/errors.go

@@ -0,0 +1,105 @@
+package cli
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os"
+
+	"github.com/coder/coder/v2/cli/clibase"
+	"github.com/coder/coder/v2/codersdk"
+	"golang.org/x/xerrors"
+)
+
+func (RootCmd) errorExample() *clibase.Cmd {
+	errorCmd := func(use string, err error) *clibase.Cmd {
+		return &clibase.Cmd{
+			Use: use,
+			Handler: func(inv *clibase.Invocation) error {
+				return err
+			},
+		}
+	}
+
+	// Make an api error
+	recorder := httptest.NewRecorder()
+	recorder.WriteHeader(http.StatusBadRequest)
+	resp := recorder.Result()
+	_ = resp.Body.Close()
+	resp.Request, _ = http.NewRequest(http.MethodPost, "http://example.com", nil)
+	apiError := codersdk.ReadBodyAsError(resp)
+	//nolint:errorlint,forcetypeassert
+	apiError.(*codersdk.Error).Response = codersdk.Response{
+		Message: "Top level sdk error message.",
+		Detail:  "magic dust unavailable, please try again later",
+		Validations: []codersdk.ValidationError{
+			{
+				Field:  "region",
+				Detail: "magic dust is not available in your region",
+			},
+		},
+	}
+	//nolint:errorlint,forcetypeassert
+	apiError.(*codersdk.Error).Helper = "Have you tried turning it off and on again?"
+
+	// Some flags
+	var magicWord clibase.String
+
+	cmd := &clibase.Cmd{
+		Use:   "example-error",
+		Short: "Shows what different error messages look like",
+		Long: "This command is pretty pointless, but without it testing errors is" +
+			"difficult to visually inspect. Error message formatting is inherently" +
+			"visual, so we need a way to quickly see what they look like.",
+		Handler: func(inv *clibase.Invocation) error {
+			return inv.Command.HelpHandler(inv)
+		},
+		Children: []*clibase.Cmd{
+			// Typical codersdk api error
+			errorCmd("api", apiError),
+
+			// Typical cli error
+			errorCmd("cmd", xerrors.Errorf("some error: %w", errorWithStackTrace())),
+
+			// A multi-error
+			{
+				Use: "multi-error",
+				Handler: func(inv *clibase.Invocation) error {
+					// Closing the stdin file descriptor will cause the next close
+					// to fail. This is joined to the returned Command error.
+					if f, ok := inv.Stdin.(*os.File); ok {
+						_ = f.Close()
+					}
+
+					return xerrors.Errorf("some error: %w", errorWithStackTrace())
+				},
+			},
+
+			{
+				Use: "validation",
+				Options: clibase.OptionSet{
+					clibase.Option{
+						Name:        "magic-word",
+						Description: "Take a good guess.",
+						Required:    true,
+						Flag:        "magic-word",
+						Default:     "",
+						Value: clibase.Validate(&magicWord, func(value *clibase.String) error {
+							return xerrors.Errorf("magic word is incorrect")
+						}),
+					},
+				},
+				Handler: func(i *clibase.Invocation) error {
+					_, _ = fmt.Fprint(i.Stdout, "Try setting the --magic-word flag\n")
+					return nil
+				},
+			},
+		},
+	}
+
+	return cmd
+}
+
+func errorWithStackTrace() error {
+	return xerrors.Errorf("function decided not to work, and it never will")
+}