179 lines
4.1 KiB
Go
179 lines
4.1 KiB
Go
package cli
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import (
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"fmt"
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"io"
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"os"
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"strings"
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)
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// OsExiter is the function used when the app exits. If not set defaults to os.Exit.
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var OsExiter = os.Exit
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// ErrWriter is used to write errors to the user. This can be anything
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// implementing the io.Writer interface and defaults to os.Stderr.
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var ErrWriter io.Writer = os.Stderr
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// MultiError is an error that wraps multiple errors.
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type MultiError interface {
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error
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Errors() []error
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}
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// newMultiError creates a new MultiError. Pass in one or more errors.
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func newMultiError(err ...error) MultiError {
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ret := multiError(err)
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return &ret
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}
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type multiError []error
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// Error implements the error interface.
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func (m *multiError) Error() string {
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errs := make([]string, len(*m))
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for i, err := range *m {
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errs[i] = err.Error()
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}
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return strings.Join(errs, "\n")
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}
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// Errors returns a copy of the errors slice
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func (m *multiError) Errors() []error {
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errs := make([]error, len(*m))
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for _, err := range *m {
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errs = append(errs, err)
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}
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return errs
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}
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type requiredFlagsErr interface {
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error
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getMissingFlags() []string
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}
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type errRequiredFlags struct {
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missingFlags []string
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}
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func (e *errRequiredFlags) Error() string {
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numberOfMissingFlags := len(e.missingFlags)
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if numberOfMissingFlags == 1 {
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return fmt.Sprintf("Required flag %q not set", e.missingFlags[0])
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}
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joinedMissingFlags := strings.Join(e.missingFlags, ", ")
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return fmt.Sprintf("Required flags %q not set", joinedMissingFlags)
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}
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func (e *errRequiredFlags) getMissingFlags() []string {
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return e.missingFlags
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}
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// ErrorFormatter is the interface that will suitably format the error output
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type ErrorFormatter interface {
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Format(s fmt.State, verb rune)
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}
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// ExitCoder is the interface checked by `App` and `Command` for a custom exit
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// code
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type ExitCoder interface {
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error
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ExitCode() int
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}
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type exitError struct {
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exitCode int
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err error
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}
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// NewExitError calls Exit to create a new ExitCoder.
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//
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// Deprecated: This function is a duplicate of Exit and will eventually be removed.
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func NewExitError(message interface{}, exitCode int) ExitCoder {
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return Exit(message, exitCode)
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}
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// Exit wraps a message and exit code into an error, which by default is
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// handled with a call to os.Exit during default error handling.
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//
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// This is the simplest way to trigger a non-zero exit code for an App without
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// having to call os.Exit manually. During testing, this behavior can be avoided
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// by overriding the ExitErrHandler function on an App or the package-global
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// OsExiter function.
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func Exit(message interface{}, exitCode int) ExitCoder {
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var err error
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switch e := message.(type) {
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case ErrorFormatter:
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err = fmt.Errorf("%+v", message)
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case error:
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err = e
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default:
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err = fmt.Errorf("%+v", message)
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}
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return &exitError{
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err: err,
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exitCode: exitCode,
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}
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}
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func (ee *exitError) Error() string {
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return ee.err.Error()
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}
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func (ee *exitError) ExitCode() int {
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return ee.exitCode
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}
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func (ee *exitError) Unwrap() error {
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return ee.err
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}
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// HandleExitCoder handles errors implementing ExitCoder by printing their
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// message and calling OsExiter with the given exit code.
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//
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// If the given error instead implements MultiError, each error will be checked
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// for the ExitCoder interface, and OsExiter will be called with the last exit
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// code found, or exit code 1 if no ExitCoder is found.
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//
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// This function is the default error-handling behavior for an App.
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func HandleExitCoder(err error) {
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if err == nil {
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return
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}
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if exitErr, ok := err.(ExitCoder); ok {
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if err.Error() != "" {
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if _, ok := exitErr.(ErrorFormatter); ok {
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_, _ = fmt.Fprintf(ErrWriter, "%+v\n", err)
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} else {
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_, _ = fmt.Fprintln(ErrWriter, err)
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}
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}
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OsExiter(exitErr.ExitCode())
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return
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}
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if multiErr, ok := err.(MultiError); ok {
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code := handleMultiError(multiErr)
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OsExiter(code)
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return
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}
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}
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func handleMultiError(multiErr MultiError) int {
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code := 1
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for _, merr := range multiErr.Errors() {
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if multiErr2, ok := merr.(MultiError); ok {
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code = handleMultiError(multiErr2)
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} else if merr != nil {
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fmt.Fprintln(ErrWriter, merr)
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if exitErr, ok := merr.(ExitCoder); ok {
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code = exitErr.ExitCode()
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}
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}
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}
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return code
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}
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