test: increase unit test coverage to 80%

.github/.codecov.yml

@@ -15,7 +15,7 @@ coverage:
   status:
     project:
       default:
-        target: 75%
+        target: 80%
         if_ci_failed: error
     patch:
       default:

content/graph_test.go

@@ -19,12 +19,14 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"reflect"
 	"testing"
 
 	"github.com/opencontainers/go-digest"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras-go/v2/content"
+	"oras.land/oras-go/v2/errdef"
 	"oras.land/oras-go/v2/internal/cas"
 	"oras.land/oras-go/v2/internal/docker"
 	"oras.land/oras-go/v2/internal/spec"
@@ -389,3 +391,100 @@ func TestSuccessors_otherMediaType(t *testing.T) {
 		t.Errorf("Successors() = %v, want nil", got)
 	}
 }
+
+func TestSuccessors_ErrNotFound(t *testing.T) {
+	tests := []struct {
+		name string
+		desc ocispec.Descriptor
+	}{
+		{
+			name: "docker manifest",
+			desc: ocispec.Descriptor{
+				MediaType: docker.MediaTypeManifest,
+			},
+		},
+		{
+			name: "image manifest",
+			desc: ocispec.Descriptor{
+				MediaType: ocispec.MediaTypeImageManifest,
+			},
+		},
+		{
+			name: "docker manifest list",
+			desc: ocispec.Descriptor{
+				MediaType: docker.MediaTypeManifestList,
+			},
+		},
+		{
+			name: "image index",
+			desc: ocispec.Descriptor{
+				MediaType: ocispec.MediaTypeImageIndex,
+			},
+		},
+		{
+			name: "artifact manifest",
+			desc: ocispec.Descriptor{
+				MediaType: spec.MediaTypeArtifactManifest,
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := context.Background()
+			fetcher := cas.NewMemory()
+			if _, err := content.Successors(ctx, fetcher, tt.desc); !errors.Is(err, errdef.ErrNotFound) {
+				t.Errorf("Successors() error = %v, wantErr = %v", err, errdef.ErrNotFound)
+			}
+		})
+	}
+}
+
+func TestSuccessors_UnmarshalError(t *testing.T) {
+	tests := []struct {
+		name      string
+		mediaType string
+	}{
+		{
+			name:      "docker manifest",
+			mediaType: docker.MediaTypeManifest,
+		},
+		{
+			name:      "image manifest",
+			mediaType: ocispec.MediaTypeImageManifest,
+		},
+		{
+			name:      "docker manifest list",
+			mediaType: docker.MediaTypeManifestList,
+		},
+		{
+			name:      "image index",
+			mediaType: ocispec.MediaTypeImageIndex,
+		},
+		{
+			name:      "artifact manifest",
+			mediaType: spec.MediaTypeArtifactManifest,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := context.Background()
+			fetcher := cas.NewMemory()
+
+			// prepare test content
+			data := "invalid json"
+			desc := ocispec.Descriptor{
+				MediaType: tt.mediaType,
+				Digest:    digest.FromString(data),
+				Size:      int64(len(data)),
+			}
+			if err := fetcher.Push(ctx, desc, bytes.NewReader([]byte(data))); err != nil {
+				t.Fatalf("failed to push test content to fetcher: %v", err)
+			}
+
+			// test Successors
+			if _, err := content.Successors(ctx, fetcher, desc); err == nil {
+				t.Error("Successors() error = nil, wantErr = true")
+			}
+		})
+	}
+}

content/limitedstorage_test.go

@@ -0,0 +1,116 @@
+/*
+Copyright The ORAS 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 content_test
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"reflect"
+	"testing"
+
+	"github.com/opencontainers/go-digest"
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+	"oras.land/oras-go/v2/content"
+	"oras.land/oras-go/v2/errdef"
+	"oras.land/oras-go/v2/internal/cas"
+)
+
+func TestLimitedStorage_Push(t *testing.T) {
+	data := []byte("test")
+	size := int64(len(data))
+	dgst := digest.FromBytes(data)
+	mediaType := "application/vnd.test"
+
+	tests := []struct {
+		name    string
+		desc    ocispec.Descriptor
+		limit   int64
+		wantErr error
+	}{
+		{
+			name: "descriptor size matches actual size and is within limit",
+			desc: ocispec.Descriptor{
+				MediaType: mediaType,
+				Size:      size,
+				Digest:    dgst,
+			},
+			limit:   size,
+			wantErr: nil,
+		},
+		{
+			name: "descriptor size matches actual size but exeeds limit",
+			desc: ocispec.Descriptor{
+				MediaType: mediaType,
+				Size:      size,
+				Digest:    dgst,
+			},
+			limit:   size - 1,
+			wantErr: errdef.ErrSizeExceedsLimit,
+		},
+		{
+			name: "descriptor size mismatches actual size and is within limit",
+			desc: ocispec.Descriptor{
+				MediaType: mediaType,
+				Size:      size - 1,
+				Digest:    dgst,
+			},
+			limit:   size,
+			wantErr: content.ErrMismatchedDigest,
+		},
+		{
+			name: "descriptor size mismatches actual size and exceeds limit",
+			desc: ocispec.Descriptor{
+				MediaType: mediaType,
+				Size:      size + 1,
+				Digest:    dgst,
+			},
+			limit:   size,
+			wantErr: errdef.ErrSizeExceedsLimit,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := context.Background()
+			ls := content.LimitStorage(cas.NewMemory(), tt.limit)
+
+			// test Push
+			err := ls.Push(ctx, tt.desc, bytes.NewReader(data))
+			if err != nil {
+				if errors.Is(err, tt.wantErr) {
+					return
+				}
+				t.Errorf("LimitedStorage.Push() error = %v, wantErr %v", err, tt.wantErr)
+			}
+
+			// verify
+			rc, err := ls.Storage.Fetch(ctx, tt.desc)
+			if err != nil {
+				t.Fatalf("LimitedStorage.Fetch() error = %v", err)
+			}
+			defer rc.Close()
+
+			got, err := io.ReadAll(rc)
+			if err != nil {
+				t.Fatalf("io.ReadAll() error = %v", err)
+			}
+			if !reflect.DeepEqual(got, data) {
+				t.Errorf("LimitedStorage.Fetch() = %v, want %v", got, data)
+			}
+		})
+	}
+}

content/storage_test.go

@@ -0,0 +1,58 @@
+/*
+Copyright The ORAS 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 content
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"testing"
+
+	"github.com/opencontainers/go-digest"
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+func TestFetcherFunc_Fetch(t *testing.T) {
+	data := []byte("test content")
+	desc := ocispec.Descriptor{
+		MediaType: "test",
+		Digest:    digest.FromBytes(data),
+		Size:      int64(len(data)),
+	}
+
+	fetcherFunc := FetcherFunc(func(ctx context.Context, target ocispec.Descriptor) (io.ReadCloser, error) {
+		if target.Digest != desc.Digest {
+			return nil, errors.New("content not found")
+		}
+		return io.NopCloser(bytes.NewReader(data)), nil
+	})
+
+	ctx := context.Background()
+	rc, err := fetcherFunc.Fetch(ctx, desc)
+	if err != nil {
+		t.Fatalf("FetcherFunc.Fetch() error = %v", err)
+	}
+	defer rc.Close()
+
+	got, err := io.ReadAll(rc)
+	if err != nil {
+		t.Fatalf("FetcherFunc.Fetch().Read() error = %v", err)
+	}
+	if !bytes.Equal(got, data) {
+		t.Errorf("FetcherFunc.Fetch() = %v, want %v", got, data)
+	}
+}