Search in parent directories if mage files are not found

mage/main.go

@@ -319,44 +319,62 @@ func Invoke(inv Invocation) int {
 	if inv.Dir == "" {
 		inv.Dir = dotDirectory
 	}
+	inv.Dir, _ = filepath.Abs(inv.Dir)
 	if inv.WorkDir == "" {
 		inv.WorkDir = inv.Dir
 	}
-	magefilesDir := filepath.Join(inv.Dir, MagefilesDirName)
-	// . will be default unless we find a mage folder.
-	mfSt, err := os.Stat(magefilesDir)
-	if err == nil {
-		if mfSt.IsDir() {
-			stderrBuf := &bytes.Buffer{}
-			originalDir := inv.Dir
-			inv.Dir = magefilesDir // preemptive assignment
-			// TODO: Remove this fallback and the above Magefiles invocation when the bw compatibility is removed.
-			files, err := Magefiles(originalDir, inv.GOOS, inv.GOARCH, inv.GoCmd, stderrBuf, false, inv.Debug)
-			if err == nil {
-				if len(files) != 0 {
-					errlog.Println("[WARNING] You have both a magefiles directory and mage files in the " +
-						"current directory, in future versions the files will be ignored in favor of the directory")
-					inv.Dir = originalDir
+	var (
+		files  []string
+		err    error
+		errMsg string
+	)
+
+	for len(files) == 0 && len(inv.Dir) > 1 {
+		magefilesDir := filepath.Join(inv.Dir, MagefilesDirName)
+		// . will be default unless we find a mage folder.
+		mfSt, err := os.Stat(magefilesDir)
+		if err == nil {
+			if mfSt.IsDir() {
+				stderrBuf := &bytes.Buffer{}
+				originalDir := inv.Dir
+				inv.Dir = magefilesDir // preemptive assignment
+				// TODO: Remove this fallback and the above Magefiles invocation when the bw compatibility is removed.
+				files, err := Magefiles(originalDir, inv.GOOS, inv.GOARCH, inv.GoCmd, stderrBuf, false, inv.Debug)
+				if err == nil {
+					if len(files) != 0 {
+						errlog.Println("[WARNING] You have both a magefiles directory and mage files in the " +
+							"current directory, in future versions the files will be ignored in favor of the directory")
+						inv.Dir = originalDir
+					}
 				}
 			}
 		}
-	}
 
-	if inv.CacheDir == "" {
-		inv.CacheDir = mg.CacheDir()
-	}
+		files, err = Magefiles(inv.Dir, inv.GOOS, inv.GOARCH, inv.GoCmd, inv.Stderr, inv.UsesMagefiles(), inv.Debug)
+		if err != nil {
+			errMsg = fmt.Sprintf("Error determining list of magefiles: %s", err)
+			inv.Dir = filepath.Dir(inv.Dir)
+			files = []string{}
+			continue
+		}
 
-	files, err := Magefiles(inv.Dir, inv.GOOS, inv.GOARCH, inv.GoCmd, inv.Stderr, inv.UsesMagefiles(), inv.Debug)
-	if err != nil {
-		errlog.Println("Error determining list of magefiles:", err)
-		return 1
+		if len(files) == 0 {
+			errMsg = "No .go files marked with the mage build tag in this directory or any parent directory."
+			inv.Dir = filepath.Dir(inv.Dir)
+			files = []string{}
+			continue
+		}
 	}
-
 	if len(files) == 0 {
-		errlog.Println("No .go files marked with the mage build tag in this directory.")
+		errlog.Println(errMsg)
 		return 1
 	}
 	debug.Printf("found magefiles: %s", strings.Join(files, ", "))
+
+	if inv.CacheDir == "" {
+		inv.CacheDir = mg.CacheDir()
+	}
+
 	exePath := inv.CompileOut
 	if inv.CompileOut == "" {
 		exePath, err = ExeName(inv.GoCmd, inv.CacheDir, files)

mage/main_test.go

@@ -375,6 +375,54 @@ func TestMagefilesFolder(t *testing.T) {
 	}
 }
 
+func TestFindFilesInParents(t *testing.T) {
+	resetTerm()
+	wd, err := os.Getwd()
+	t.Log(wd)
+	if err != nil {
+		t.Fatalf("finding current working directory: %v", err)
+	}
+	if err := os.Chdir("testdata/with_magefiles_folder/sub_folder"); err != nil {
+		t.Fatalf("changing to magefolders tests data: %v", err)
+	}
+	// restore previous state
+	defer os.Chdir(wd)
+
+	stderr := &bytes.Buffer{}
+	stdout := &bytes.Buffer{}
+	inv := Invocation{
+		Dir:    "",
+		Stdout: stdout,
+		Stderr: stderr,
+		List:   true,
+	}
+	// get magefiles even when in subfolder
+	code := Invoke(inv)
+	if code != 0 {
+		t.Errorf("expected to exit with code 0, but got %v, stderr: %s", code, stderr)
+	}
+	expected := "Targets:\n  build    \n"
+	actual := stdout.String()
+	if actual != expected {
+		t.Fatalf("expected %q but got %q", expected, actual)
+	}
+	stdout.Truncate(0) // clear buffer for next test case
+
+	// ignore parent magefiles when subfolder has magefiles
+	if err := os.Chdir("sub_folder2"); err != nil {
+		t.Fatalf("changing to magefolders tests data: %v", err)
+	}
+	code = Invoke(inv)
+	if code != 0 {
+		t.Errorf("expected to exit with code 0, but got %v, stderr: %s", code, stderr)
+	}
+	expected = "Targets:\n  subBuild    \n"
+	actual = stdout.String()
+	if actual != expected {
+		t.Fatalf("expected %q but got %q", expected, actual)
+	}
+}
+
 func TestMagefilesFolderMixedWithMagefiles(t *testing.T) {
 	resetTerm()
 	wd, err := os.Getwd()

mage/testdata/with_magefiles_folder/sub_folder/sub_folder2/mage_helpers.go

@@ -0,0 +1,6 @@
+//go:build mage
+// +build mage
+
+package main
+
+func foo() {}

mage/testdata/with_magefiles_folder/sub_folder/sub_folder2/magefile.go

@@ -0,0 +1,6 @@
+//go:build mage
+// +build mage
+
+package main
+
+func SubBuild() {}