test(compiler): make special vars test OS-portable

Build paths from t.TempDir() so they are valid absolute paths on
Windows too (filepath.IsAbs treats `/abs/path` as non-absolute there).

compiler.go

@@ -15,6 +15,7 @@ import (
 	"github.com/go-task/task/v3/internal/logger"
 	"github.com/go-task/task/v3/internal/templater"
 	"github.com/go-task/task/v3/internal/version"
+	"github.com/go-task/task/v3/taskfile"
 	"github.com/go-task/task/v3/taskfile/ast"
 )
 
@@ -201,10 +202,19 @@ func (c *Compiler) getSpecialVars(t *ast.Task, call *Call) (map[string]string, e
 	// Use filepath.ToSlash for all paths to ensure consistent forward slashes
 	// across platforms. This prevents issues with backslashes being interpreted
 	// as escape sequences when paths are used in shell commands on Windows.
+	var rootTaskfile, rootDir string
+	if taskfile.IsRemoteEntrypoint(c.Entrypoint) {
+		rootTaskfile = c.Entrypoint
+		rootDir = ""
+	} else {
+		rootTaskfile = filepath.ToSlash(filepathext.SmartJoin(c.Dir, c.Entrypoint))
+		rootDir = filepath.ToSlash(c.Dir)
+	}
+
 	allVars := map[string]string{
 		"TASK_EXE":            filepath.ToSlash(os.Args[0]),
-		"ROOT_TASKFILE":       filepath.ToSlash(filepathext.SmartJoin(c.Dir, c.Entrypoint)),
-		"ROOT_DIR":            filepath.ToSlash(c.Dir),
+		"ROOT_TASKFILE":       rootTaskfile,
+		"ROOT_DIR":            rootDir,
 		"USER_WORKING_DIR":    filepath.ToSlash(c.UserWorkingDir),
 		"TASK_VERSION":        version.GetVersion(),
 		"PATH_LIST_SEPARATOR": string(os.PathListSeparator),
@@ -212,9 +222,22 @@ func (c *Compiler) getSpecialVars(t *ast.Task, call *Call) (map[string]string, e
 	}
 	if t != nil {
 		allVars["TASK"] = t.Task
-		allVars["TASK_DIR"] = filepath.ToSlash(filepathext.SmartJoin(c.Dir, t.Dir))
-		allVars["TASKFILE"] = filepath.ToSlash(t.Location.Taskfile)
-		allVars["TASKFILE_DIR"] = filepath.ToSlash(filepath.Dir(t.Location.Taskfile))
+		if taskfile.IsRemoteEntrypoint(t.Location.Taskfile) {
+			allVars["TASKFILE"] = t.Location.Taskfile
+			allVars["TASKFILE_DIR"] = ""
+			switch {
+			case t.Dir == "":
+				allVars["TASK_DIR"] = filepath.ToSlash(c.UserWorkingDir)
+			case filepath.IsAbs(t.Dir):
+				allVars["TASK_DIR"] = filepath.ToSlash(t.Dir)
+			default:
+				allVars["TASK_DIR"] = filepath.ToSlash(filepathext.SmartJoin(c.UserWorkingDir, t.Dir))
+			}
+		} else {
+			allVars["TASK_DIR"] = filepath.ToSlash(filepathext.SmartJoin(c.Dir, t.Dir))
+			allVars["TASKFILE"] = filepath.ToSlash(t.Location.Taskfile)
+			allVars["TASKFILE_DIR"] = filepath.ToSlash(filepath.Dir(t.Location.Taskfile))
+		}
 	} else {
 		allVars["TASK"] = ""
 		allVars["TASK_DIR"] = ""

compiler_internal_test.go

@@ -0,0 +1,135 @@
+package task
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/go-task/task/v3/internal/filepathext"
+	"github.com/go-task/task/v3/taskfile/ast"
+)
+
+func TestGetSpecialVarsRemote(t *testing.T) {
+	t.Parallel()
+
+	uwd := t.TempDir()
+	uwdSlash := filepath.ToSlash(uwd)
+	localProj := filepath.Join(uwd, "proj")
+	localProjSlash := filepath.ToSlash(localProj)
+	localTaskfile := filepath.Join(localProj, "Taskfile.yml")
+	localTaskfileSlash := filepath.ToSlash(localTaskfile)
+	absTaskDir := filepath.Join(uwd, "opt", "work")
+	absTaskDirSlash := filepath.ToSlash(absTaskDir)
+
+	tests := []struct {
+		name             string
+		entrypoint       string
+		compilerDir      string
+		taskDir          string
+		taskfileLocation string
+		wantRootTaskfile string
+		wantRootDir      string
+		wantTaskfile     string
+		wantTaskfileDir  string
+		wantTaskDir      string
+	}{
+		{
+			name:             "local entrypoint, local task",
+			entrypoint:       localTaskfile,
+			compilerDir:      localProj,
+			taskDir:          "",
+			taskfileLocation: localTaskfile,
+			wantRootTaskfile: localTaskfileSlash,
+			wantRootDir:      localProjSlash,
+			wantTaskfile:     localTaskfileSlash,
+			wantTaskfileDir:  localProjSlash,
+			wantTaskDir:      localProjSlash,
+		},
+		{
+			name:             "https entrypoint, empty task.dir",
+			entrypoint:       "https://taskfile.dev/Taskfile.yml",
+			compilerDir:      "",
+			taskDir:          "",
+			taskfileLocation: "https://taskfile.dev/Taskfile.yml",
+			wantRootTaskfile: "https://taskfile.dev/Taskfile.yml",
+			wantRootDir:      "",
+			wantTaskfile:     "https://taskfile.dev/Taskfile.yml",
+			wantTaskfileDir:  "",
+			wantTaskDir:      uwdSlash,
+		},
+		{
+			name:             "https entrypoint, relative task.dir",
+			entrypoint:       "https://taskfile.dev/Taskfile.yml",
+			compilerDir:      "",
+			taskDir:          "subdir",
+			taskfileLocation: "https://taskfile.dev/Taskfile.yml",
+			wantRootTaskfile: "https://taskfile.dev/Taskfile.yml",
+			wantRootDir:      "",
+			wantTaskfile:     "https://taskfile.dev/Taskfile.yml",
+			wantTaskfileDir:  "",
+			wantTaskDir:      filepath.ToSlash(filepathext.SmartJoin(uwd, "subdir")),
+		},
+		{
+			name:             "https entrypoint, absolute task.dir",
+			entrypoint:       "https://taskfile.dev/Taskfile.yml",
+			compilerDir:      "",
+			taskDir:          absTaskDir,
+			taskfileLocation: "https://taskfile.dev/Taskfile.yml",
+			wantRootTaskfile: "https://taskfile.dev/Taskfile.yml",
+			wantRootDir:      "",
+			wantTaskfile:     "https://taskfile.dev/Taskfile.yml",
+			wantTaskfileDir:  "",
+			wantTaskDir:      absTaskDirSlash,
+		},
+		{
+			name:             "git entrypoint",
+			entrypoint:       "https://github.com/foo/bar.git//Taskfile.yml?ref=main",
+			compilerDir:      "",
+			taskDir:          "",
+			taskfileLocation: "https://github.com/foo/bar.git//Taskfile.yml?ref=main",
+			wantRootTaskfile: "https://github.com/foo/bar.git//Taskfile.yml?ref=main",
+			wantRootDir:      "",
+			wantTaskfile:     "https://github.com/foo/bar.git//Taskfile.yml?ref=main",
+			wantTaskfileDir:  "",
+			wantTaskDir:      uwdSlash,
+		},
+		{
+			name:             "local root, remote included task",
+			entrypoint:       localTaskfile,
+			compilerDir:      localProj,
+			taskDir:          "",
+			taskfileLocation: "https://taskfile.dev/included.yml",
+			wantRootTaskfile: localTaskfileSlash,
+			wantRootDir:      localProjSlash,
+			wantTaskfile:     "https://taskfile.dev/included.yml",
+			wantTaskfileDir:  "",
+			wantTaskDir:      uwdSlash,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			c := &Compiler{
+				Dir:            tt.compilerDir,
+				Entrypoint:     tt.entrypoint,
+				UserWorkingDir: uwd,
+			}
+			task := &ast.Task{
+				Task:     "mytask",
+				Dir:      tt.taskDir,
+				Location: &ast.Location{Taskfile: tt.taskfileLocation},
+			}
+
+			vars, err := c.getSpecialVars(task, nil)
+			assert.NoError(t, err)
+			assert.Equal(t, tt.wantRootTaskfile, vars["ROOT_TASKFILE"], "ROOT_TASKFILE")
+			assert.Equal(t, tt.wantRootDir, vars["ROOT_DIR"], "ROOT_DIR")
+			assert.Equal(t, tt.wantTaskfile, vars["TASKFILE"], "TASKFILE")
+			assert.Equal(t, tt.wantTaskfileDir, vars["TASKFILE_DIR"], "TASKFILE_DIR")
+			assert.Equal(t, tt.wantTaskDir, vars["TASK_DIR"], "TASK_DIR")
+		})
+	}
+}

taskfile/node.go

@@ -73,7 +73,7 @@ func NewNode(
 	return node, err
 }
 
-func isRemoteEntrypoint(entrypoint string) bool {
+func IsRemoteEntrypoint(entrypoint string) bool {
 	scheme, _ := getScheme(entrypoint)
 	switch scheme {
 	case "git", "http", "https":

taskfile/node_file.go

@@ -60,7 +60,7 @@ func (node *FileNode) Read() ([]byte, error) {
 
 func (node *FileNode) ResolveEntrypoint(entrypoint string) (string, error) {
 	// If the file is remote, we don't need to resolve the path
-	if isRemoteEntrypoint(entrypoint) {
+	if IsRemoteEntrypoint(entrypoint) {
 		return entrypoint, nil
 	}
 

taskfile/node_git.go

@@ -188,7 +188,7 @@ func (node *GitNode) ReadContext(ctx context.Context) ([]byte, error) {
 
 func (node *GitNode) ResolveEntrypoint(entrypoint string) (string, error) {
 	// If the file is remote, we don't need to resolve the path
-	if isRemoteEntrypoint(entrypoint) {
+	if IsRemoteEntrypoint(entrypoint) {
 		return entrypoint, nil
 	}
 

taskfile/node_stdin.go

@@ -42,7 +42,7 @@ func (node *StdinNode) Read() ([]byte, error) {
 
 func (node *StdinNode) ResolveEntrypoint(entrypoint string) (string, error) {
 	// If the file is remote, we don't need to resolve the path
-	if isRemoteEntrypoint(entrypoint) {
+	if IsRemoteEntrypoint(entrypoint) {
 		return entrypoint, nil
 	}
 

website/src/docs/experiments/remote-taskfiles.md

@@ -190,6 +190,21 @@ includes:
   my-remote-namespace: https://{{.TOKEN}}@raw.githubusercontent.com/my-org/my-repo/main/Taskfile.yml
 ```
 
+## Special Variables
+
+The file-path [special variables](../reference/templating.md#file-paths) behave
+differently when a Taskfile is loaded from a remote source, because there is no
+local file or directory that corresponds 1:1 to the Taskfile:
+
+| Variable                     | Value when loaded remotely                                                                                                                             |
+| ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| `TASKFILE` / `ROOT_TASKFILE` | The original URL, unchanged                                                                                                                            |
+| `TASKFILE_DIR` / `ROOT_DIR`  | Empty string — a directory variable cannot point to a URL                                                                                              |
+| `TASK_DIR`                   | Resolved against `USER_WORKING_DIR` (relative `dir:` → joined with `USER_WORKING_DIR`, empty `dir:` → `USER_WORKING_DIR`, absolute `dir:` → kept as-is) |
+
+If a remote Taskfile includes a local Taskfile (or vice-versa), each variable
+reflects the source of the Taskfile it refers to.
+
 ## Security
 
 ### Automatic checksums