Add support for using embedded file systems. (#58)

Co-authored-by: sailormoon <sailormoon@users.noreply.github.com>

.drone.yml

@@ -15,15 +15,15 @@ trigger:
 
 steps:
   - name: lint
-    image: golang:1.13
+    image: golang:1.16
     pull: always
     commands:
       - go vet -all .
       - go get -u github.com/mgechev/revive
       - revive -config .revive.toml -exclude=./vendor/... ./...
 
   - name: test
-    image: golang:1.13
+    image: golang:1.16
     pull: always
     commands:
       - go test -v .

go.mod

@@ -1,6 +1,6 @@
 module github.com/lafriks/go-tiled
 
-go 1.13
+go 1.16
 
 require (
 	github.com/disintegration/imaging v1.6.2

tiled.go

@@ -25,7 +25,7 @@ package tiled
 import (
 	"encoding/xml"
 	"io"
-	"net/http"
+	"io/fs"
 	"os"
 	"path/filepath"
 )
@@ -47,12 +47,12 @@ type Loader struct {
 	// resources it may reference.
 	//
 	// A nil FileSystem uses the local file system.
-	FileSystem http.FileSystem
+	FileSystem fs.FS
 }
 
 // open opens the given file using the Loader's FileSystem, or uses os.Open
 // if l or l.FileSystem is nil.
-func (l *Loader) open(name string) (http.File, error) {
+func (l *Loader) open(name string) (fs.File, error) {
 	if l == nil || l.FileSystem == nil {
 		return os.Open(name)
 	}
@@ -83,10 +83,6 @@ func (l *Loader) LoadFromFile(fileName string) (*Map, error) {
 	}
 	defer f.Close()
 
-	dir, err := filepath.Abs(filepath.Dir(fileName))
-	if err != nil {
-		return nil, err
-	}
-
+	dir := filepath.Dir(fileName)
 	return l.LoadFromReader(dir, f)
 }

tiled_test.go

@@ -24,9 +24,10 @@ package tiled
 
 import (
 	"bytes"
+	"embed"
 	"encoding/xml"
 	"image/color"
-	"net/http"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -208,7 +209,7 @@ type testFileSystem struct {
 	AttemptedOpen []string
 }
 
-func (t *testFileSystem) Open(filename string) (http.File, error) {
+func (t *testFileSystem) Open(filename string) (fs.File, error) {
 	t.AttemptedOpen = append(t.AttemptedOpen, filename)
 	if filepath.Base(filename) == "loader.tmx" {
 		return os.Open(filepath.Join(GetAssetsDirectory(), "loader.tmx"))
@@ -233,6 +234,51 @@ func TestLoader(t *testing.T) {
 	assert.Equal(t, []string{mapFile, filepath.Join(GetAssetsDirectory(), "..", "README.md")}, fs.AttemptedOpen)
 }
 
+//go:embed assets/**
+var assetsFS embed.FS
+
+func TestEmbeddedLoader(t *testing.T) {
+	loader := &Loader{
+		FileSystem: assetsFS,
+	}
+	tcs := []struct {
+		name string
+		load func() (*Map, error)
+	}{
+		{
+			name: "LoadFromReader",
+			load: func() (*Map, error) {
+				file, err := assetsFS.Open("assets/test2.tmx")
+				if err != nil {
+					return nil, err
+				}
+				return loader.LoadFromReader("assets", file)
+			},
+		},
+		{
+			name: "LoadFromFile",
+			load: func() (*Map, error) {
+				return loader.LoadFromFile("assets/test2.tmx")
+			},
+		},
+	}
+
+	for _, tc := range tcs {
+		t.Run(tc.name, func(t *testing.T) {
+			m, err := tc.load()
+			assert.NoError(t, err)
+
+			assert.Equal(t, m.Version, "1.2")
+			assert.Equal(t, m.TiledVersion, "1.2.3")
+
+			assert.Len(t, m.Tilesets, 1)
+			tileset := m.Tilesets[0]
+			assert.Equal(t, tileset.Version, "1.2")
+			assert.Equal(t, tileset.TiledVersion, "1.2.3")
+		})
+	}
+}
+
 func TestParseHexColor(t *testing.T) {
 	type test struct {
 		name  string