feat: cache resized images

diskcache/file_cache_test.go

@@ -0,0 +1,55 @@
+package diskcache
+
+import (
+	"context"
+	"path/filepath"
+	"testing"
+
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFileCache(t *testing.T) {
+	ctx := context.Background()
+	const (
+		key            = "key"
+		value          = "some text"
+		newValue       = "new text"
+		cacheRoot      = "/cache"
+		cachedFilePath = "a/62/a62f2225bf70bfaccbc7f1ef2a397836717377de"
+	)
+
+	fs := afero.NewMemMapFs()
+	cache := New(fs, "/cache")
+
+	// store new key
+	err := cache.Store(ctx, key, []byte(value))
+	require.NoError(t, err)
+	checkValue(t, ctx, fs, filepath.Join(cacheRoot, cachedFilePath), cache, key, value)
+
+	// update existing key
+	err = cache.Store(ctx, key, []byte(newValue))
+	require.NoError(t, err)
+	checkValue(t, ctx, fs, filepath.Join(cacheRoot, cachedFilePath), cache, key, newValue)
+
+	// delete key
+	err = cache.Delete(ctx, key)
+	require.NoError(t, err)
+	exists, err := afero.Exists(fs, filepath.Join(cacheRoot, cachedFilePath))
+	require.NoError(t, err)
+	require.False(t, exists)
+}
+
+func checkValue(t *testing.T, ctx context.Context, fs afero.Fs, fileFullPath string, cache *FileCache, key, wantValue string) { //nolint:golint
+	t.Helper()
+	// check actual file content
+	b, err := afero.ReadFile(fs, fileFullPath)
+	require.NoError(t, err)
+	require.Equal(t, wantValue, string(b))
+
+	// check cache content
+	b, ok, err := cache.Load(ctx, key)
+	require.NoError(t, err)
+	require.True(t, ok)
+	require.Equal(t, wantValue, string(b))
+}