Move error types to its own file

errors.go

@@ -0,0 +1,33 @@
+package task
+
+import (
+	"fmt"
+)
+
+// ErrNoTaskFile is returned when the program can not find a proper TaskFile
+var ErrNoTaskFile = fmt.Errorf(`No task file found (is it named "%s"?)`, TaskFilePath)
+
+type taskNotFoundError struct {
+	taskName string
+}
+
+func (err *taskNotFoundError) Error() string {
+	return fmt.Sprintf(`Task "%s" not found`, err.taskName)
+}
+
+type taskRunError struct {
+	taskName string
+	err      error
+}
+
+func (err *taskRunError) Error() string {
+	return fmt.Sprintf(`Failed to run task "%s": %v`, err.taskName, err.err)
+}
+
+type cyclicDepError struct {
+	taskName string
+}
+
+func (err *cyclicDepError) Error() string {
+	return fmt.Sprintf(`Cyclic dependency of task "%s" detected`, err.taskName)
+}

task.go

@@ -2,8 +2,6 @@ package task
 
 import (
 	"encoding/json"
-	"errors"
-	"fmt"
 	"io/ioutil"
 	"log"
 	"os"
@@ -49,31 +47,6 @@ type Task struct {
 	Dir       string
 }
 
-type taskNotFoundError struct {
-	taskName string
-}
-
-func (err *taskNotFoundError) Error() string {
-	return fmt.Sprintf(`Task "%s" not found`, err.taskName)
-}
-
-type taskRunError struct {
-	taskName string
-	err      error
-}
-
-func (err *taskRunError) Error() string {
-	return fmt.Sprintf(`Failed to run task "%s": %v`, err.taskName, err.err)
-}
-
-type cyclicDepError struct {
-	taskName string
-}
-
-func (err *cyclicDepError) Error() string {
-	return fmt.Sprintf(`Cyclic dependency of task "%s" detected`, err.taskName)
-}
-
 // Run runs Task
 func Run() {
 	log.SetFlags(0)
@@ -175,6 +148,3 @@ func readTaskfile() (tasks map[string]*Task, err error) {
 	}
 	return nil, ErrNoTaskFile
 }
-
-// ErrNoTaskFile is returns when the program can not find a proper TaskFile
-var ErrNoTaskFile = errors.New("no task file found (is it named '" + TaskFilePath + "'?)")