feat: custom error codes (#1114)

errors/errors.go

@@ -0,0 +1,40 @@
+package errors
+
+import "errors"
+
+// General exit codes
+const (
+	CodeOk      int = iota // Used when the program exits without errors
+	CodeUnknown            // Used when no other exit code is appropriate
+)
+
+// Taskfile related exit codes
+const (
+	CodeTaskfileNotFound int = iota + 100
+	CodeTaskfileAlreadyExists
+	CodeTaskfileInvalid
+)
+
+// Task related exit codes
+const (
+	CodeTaskNotFound int = iota + 200
+	CodeTaskRunError
+	CodeTaskInternal
+	CodeTaskNameConflict
+	CodeTaskCalledTooManyTimes
+)
+
+// TaskError extends the standard error interface with a Code method. This code will
+// be used as the exit code of the program which allows the user to distinguish
+// between different types of errors.
+type TaskError interface {
+	error
+	Code() int
+}
+
+// New returns an error that formats as the given text. Each call to New returns
+// a distinct error value even if the text is identical. This wraps the standard
+// errors.New function so that we don't need to alias that package.
+func New(text string) error {
+	return errors.New(text)
+}

errors/errors_task.go

@@ -0,0 +1,100 @@
+package errors
+
+import (
+	"fmt"
+	"strings"
+
+	"mvdan.cc/sh/v3/interp"
+)
+
+// TaskNotFoundError is returned when the specified task is not found in the
+// Taskfile.
+type TaskNotFoundError struct {
+	TaskName   string
+	DidYouMean string
+}
+
+func (err *TaskNotFoundError) Error() string {
+	if err.DidYouMean != "" {
+		return fmt.Sprintf(
+			`task: Task %q does not exist. Did you mean %q?`,
+			err.TaskName,
+			err.DidYouMean,
+		)
+	}
+
+	return fmt.Sprintf(`task: Task %q does not exist`, err.TaskName)
+}
+
+func (err *TaskNotFoundError) Code() int {
+	return CodeTaskNotFound
+}
+
+// TaskRunError is returned when a command in a task returns a non-zero exit
+// code.
+type TaskRunError struct {
+	TaskName string
+	Err      error
+}
+
+func (err *TaskRunError) Error() string {
+	return fmt.Sprintf(`task: Failed to run task %q: %v`, err.TaskName, err.Err)
+}
+
+func (err *TaskRunError) Code() int {
+	return CodeTaskRunError
+}
+
+func (err *TaskRunError) TaskExitCode() int {
+	if c, ok := interp.IsExitStatus(err.Err); ok {
+		return int(c)
+	}
+	return err.Code()
+}
+
+// TaskInternalError when the user attempts to invoke a task that is internal.
+type TaskInternalError struct {
+	TaskName string
+}
+
+func (err *TaskInternalError) Error() string {
+	return fmt.Sprintf(`task: Task "%s" is internal`, err.TaskName)
+}
+
+func (err *TaskInternalError) Code() int {
+	return CodeTaskInternal
+}
+
+// TaskNameConflictError is returned when multiple tasks with the same name or
+// alias are found.
+type TaskNameConflictError struct {
+	AliasName string
+	TaskNames []string
+}
+
+func (err *TaskNameConflictError) Error() string {
+	return fmt.Sprintf(`task: Multiple tasks (%s) with alias %q found`, strings.Join(err.TaskNames, ", "), err.AliasName)
+}
+
+func (err *TaskNameConflictError) Code() int {
+	return CodeTaskNameConflict
+}
+
+// TaskCalledTooManyTimesError is returned when the maximum task call limit is
+// exceeded. This is to prevent infinite loops and cyclic dependencies.
+type TaskCalledTooManyTimesError struct {
+	TaskName        string
+	MaximumTaskCall int
+}
+
+func (err *TaskCalledTooManyTimesError) Error() string {
+	return fmt.Sprintf(
+		`task: maximum task call exceeded (%d) for task %q: probably an cyclic dep or infinite loop`,
+		err.MaximumTaskCall,
+		err.TaskName,
+	)
+}
+
+func (err *TaskCalledTooManyTimesError) Code() int {
+	return CodeTaskCalledTooManyTimes
+}

errors/errors_taskfile.go

@@ -0,0 +1,51 @@
+package errors
+
+import (
+	"fmt"
+)
+
+// TaskfileNotFoundError is returned when no appropriate Taskfile is found when
+// searching the filesystem.
+type TaskfileNotFoundError struct {
+	Dir  string
+	Walk bool
+}
+
+func (err TaskfileNotFoundError) Error() string {
+	var walkText string
+	if err.Walk {
+		walkText = " (or any of the parent directories)"
+	}
+	return fmt.Sprintf(`task: No Taskfile found in "%s"%s. Use "task --init" to create a new one`, err.Dir, walkText)
+}
+
+func (err TaskfileNotFoundError) Code() int {
+	return CodeTaskfileNotFound
+}
+
+// TaskfileAlreadyExistsError is returned on creating a Taskfile if one already
+// exists.
+type TaskfileAlreadyExistsError struct{}
+
+func (err TaskfileAlreadyExistsError) Error() string {
+	return "task: A Taskfile already exists"
+}
+
+func (err TaskfileAlreadyExistsError) Code() int {
+	return CodeTaskfileAlreadyExists
+}
+
+// TaskfileInvalidError is returned when the Taskfile contains syntax errors or
+// cannot be parsed for some reason.
+type TaskfileInvalidError struct {
+	FilePath string
+	Err      error
+}
+
+func (err TaskfileInvalidError) Error() string {
+	return fmt.Sprintf("task: Failed to parse %s:\n%v", err.FilePath, err.Err)
+}
+
+func (err TaskfileInvalidError) Code() int {
+	return CodeTaskfileInvalid
+}