github.com/creachadair/ffs@v0.17.3/storage/encoded/encoded_test.go (about)

     1  // Copyright 2019 Michael J. Fromberger. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package encoded_test
    16  
    17  import (
    18  	"io"
    19  	"testing"
    20  
    21  	"github.com/creachadair/ffs/blob"
    22  	"github.com/creachadair/ffs/blob/memstore"
    23  	"github.com/creachadair/ffs/blob/storetest"
    24  	"github.com/creachadair/ffs/storage/encoded"
    25  )
    26  
    27  func TestStore(t *testing.T) {
    28  	base := memstore.New(nil)
    29  	enc := encoded.New(base, identity{})
    30  	storetest.Run(t, storetest.NopCloser(enc))
    31  }
    32  
    33  // identity implements an identity Codec, that encodes blobs as themselves.
    34  type identity struct{}
    35  
    36  // Encode encodes src to w with no transformation.
    37  func (identity) Encode(w io.Writer, src []byte) error { _, err := w.Write(src); return err }
    38  
    39  // Decode decodes src to w with no transformation.
    40  func (identity) Decode(w io.Writer, src []byte) error { _, err := w.Write(src); return err }
    41  
    42  func TestRegression(t *testing.T) {
    43  	ctx := t.Context()
    44  
    45  	t.Run("DoubleEncode", func(t *testing.T) {
    46  		// Verify that a given Put or Get only encodes/decodes once.
    47  		base := memstore.New(nil)
    48  		enc := encoded.New(base, tagger("@"))
    49  		kv := storetest.SubKV(t, ctx, enc, "test")
    50  
    51  		const testValue = "bar"
    52  		if err := kv.Put(ctx, blob.PutOptions{
    53  			Key:  "foo",
    54  			Data: []byte(testValue),
    55  		}); err != nil {
    56  			t.Fatalf("Put foo: %v", err)
    57  		}
    58  
    59  		real := storetest.SubKV(t, ctx, base, "test")
    60  		if val, err := real.Get(ctx, "foo"); err != nil {
    61  			t.Fatalf("Get foo: %v", err)
    62  		} else if got, want := string(val), testValue+"@"; got != want {
    63  			t.Errorf("Base foo: got %q, want %q", got, want)
    64  		}
    65  
    66  		if val, err := kv.Get(ctx, "foo"); err != nil {
    67  			t.Fatalf("Get foo: %v", err)
    68  		} else if got, want := string(val), testValue; got != want {
    69  			t.Errorf("Get foo: got %q, want %q", got, want)
    70  		}
    71  	})
    72  }
    73  
    74  type tagger string
    75  
    76  func (t tagger) Encode(w io.Writer, src []byte) error {
    77  	_, err := w.Write(append(src, t...))
    78  	return err
    79  }
    80  
    81  func (t tagger) Decode(w io.Writer, src []byte) error {
    82  	_, err := w.Write(src[:len(src)-1])
    83  	return err
    84  }