refactor: split read.go into taskfile.go and reader.go

taskfile/taskfile.go

@@ -0,0 +1,85 @@
+package taskfile
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/go-task/task/v3/errors"
+	"github.com/go-task/task/v3/internal/filepathext"
+	"github.com/go-task/task/v3/internal/sysinfo"
+)
+
+var (
+	// ErrIncludedTaskfilesCantHaveDotenvs is returned when a included Taskfile contains dotenvs
+	ErrIncludedTaskfilesCantHaveDotenvs = errors.New("task: Included Taskfiles can't have dotenv declarations. Please, move the dotenv declaration to the main Taskfile")
+
+	defaultTaskfiles = []string{
+		"Taskfile.yml",
+		"taskfile.yml",
+		"Taskfile.yaml",
+		"taskfile.yaml",
+		"Taskfile.dist.yml",
+		"taskfile.dist.yml",
+		"Taskfile.dist.yaml",
+		"taskfile.dist.yaml",
+	}
+)
+
+// Exists will check if a file at the given path Exists. If it does, it will
+// return the path to it. If it does not, it will search the search for any
+// files at the given path with any of the default Taskfile files names. If any
+// of these match a file, the first matching path will be returned. If no files
+// are found, an error will be returned.
+func Exists(path string) (string, error) {
+	fi, err := os.Stat(path)
+	if err != nil {
+		return "", err
+	}
+	if fi.Mode().IsRegular() {
+		return filepath.Abs(path)
+	}
+
+	for _, n := range defaultTaskfiles {
+		fpath := filepathext.SmartJoin(path, n)
+		if _, err := os.Stat(fpath); err == nil {
+			return filepath.Abs(fpath)
+		}
+	}
+
+	return "", errors.TaskfileNotFoundError{URI: path, Walk: false}
+}
+
+// ExistsWalk will check if a file at the given path exists by calling the
+// exists function. If a file is not found, it will walk up the directory tree
+// calling the exists function until it finds a file or reaches the root
+// directory. On supported operating systems, it will also check if the user ID
+// of the directory changes and abort if it does.
+func ExistsWalk(path string) (string, error) {
+	origPath := path
+	owner, err := sysinfo.Owner(path)
+	if err != nil {
+		return "", err
+	}
+	for {
+		fpath, err := Exists(path)
+		if err == nil {
+			return fpath, nil
+		}
+
+		// Get the parent path/user id
+		parentPath := filepath.Dir(path)
+		parentOwner, err := sysinfo.Owner(parentPath)
+		if err != nil {
+			return "", err
+		}
+
+		// Error if we reached the root directory and still haven't found a file
+		// OR if the user id of the directory changes
+		if path == parentPath || (parentOwner != owner) {
+			return "", errors.TaskfileNotFoundError{URI: origPath, Walk: false}
+		}
+
+		owner = parentOwner
+		path = parentPath
+	}
+}