ebitenutil: add tests for NewImageFromFileSystem

ebitenutil/fs_test.go

@@ -0,0 +1,39 @@
+// Copyright 2022 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License
+
+package ebitenutil_test
+
+import (
+	"embed"
+	"testing"
+
+	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
+)
+
+//go:embed *.png
+var images embed.FS
+
+func TestNewImageFromFileSystem(t *testing.T) {
+	img, _, err := ebitenutil.NewImageFromFileSystem(images, "text.png")
+	if err != nil {
+		t.Fatal(err)
+	}
+	w, h := img.Size()
+	if got, want := w, 192; got != want {
+		t.Errorf("got: %d, want: %d", got, want)
+	}
+	if got, want := h, 128; got != want {
+		t.Errorf("got: %d, want: %d", got, want)
+	}
+}