github.com/opcr-io/oras-go/v2@v2.0.0-20231122155130-eb4260d8a0ae/content/file/example_test.go (about)

     1  /*
     2  Copyright The ORAS Authors.
     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  
    16  // Package file_test includes all the testable examples for the file package.
    17  package file_test
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  	"os"
    23  	"path/filepath"
    24  	"testing"
    25  
    26  	"github.com/opcr-io/oras-go/v2"
    27  	"github.com/opcr-io/oras-go/v2/content/file"
    28  	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
    29  )
    30  
    31  var workingDir string // the working directory for the examples
    32  
    33  func TestMain(m *testing.M) {
    34  	// prepare test directory
    35  	var err error
    36  	workingDir, err = os.MkdirTemp("", "oras_file_example_*")
    37  	if err != nil {
    38  		panic(err)
    39  	}
    40  	tearDown := func() {
    41  		if err := os.RemoveAll(workingDir); err != nil {
    42  			panic(err)
    43  		}
    44  	}
    45  
    46  	// prepare test file 1
    47  	content := []byte("foo")
    48  	filename := "foo.txt"
    49  	path := filepath.Join(workingDir, filename)
    50  	if err := os.WriteFile(path, content, 0444); err != nil {
    51  		panic(err)
    52  	}
    53  	// prepare test file 2
    54  	content = []byte("bar")
    55  	filename = "bar.txt"
    56  	path = filepath.Join(workingDir, filename)
    57  	if err := os.WriteFile(path, content, 0444); err != nil {
    58  		panic(err)
    59  	}
    60  
    61  	// run tests
    62  	exitCode := m.Run()
    63  
    64  	// tear down and exit
    65  	tearDown()
    66  	os.Exit(exitCode)
    67  }
    68  
    69  // Example_packFiles gives an example of adding files and generating a manifest
    70  // referencing the files.
    71  func Example_packFiles() {
    72  	store, err := file.New(workingDir)
    73  	if err != nil {
    74  		panic(err)
    75  	}
    76  	defer store.Close()
    77  	ctx := context.Background()
    78  
    79  	// 1. Add files into the file store
    80  	mediaType := "example/file"
    81  	fileNames := []string{"foo.txt", "bar.txt"}
    82  	fileDescriptors := make([]ocispec.Descriptor, 0, len(fileNames))
    83  	for _, name := range fileNames {
    84  		fileDescriptor, err := store.Add(ctx, name, mediaType, "")
    85  		if err != nil {
    86  			panic(err)
    87  		}
    88  		fileDescriptors = append(fileDescriptors, fileDescriptor)
    89  
    90  		fmt.Printf("file descriptor for %s: %v\n", name, fileDescriptor)
    91  	}
    92  
    93  	// 2. Generate a manifest referencing the files
    94  	artifactType := "example/test"
    95  	manifestDescriptor, err := oras.Pack(ctx, store, artifactType, fileDescriptors, oras.PackOptions{})
    96  	if err != nil {
    97  		panic(err)
    98  	}
    99  	fmt.Println("manifest media type:", manifestDescriptor.MediaType)
   100  
   101  	// Output:
   102  	// file descriptor for foo.txt: {example/file sha256:2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae 3 [] map[org.opencontainers.image.title:foo.txt] [] <nil> }
   103  	// file descriptor for bar.txt: {example/file sha256:fcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9 3 [] map[org.opencontainers.image.title:bar.txt] [] <nil> }
   104  	// manifest media type: application/vnd.oci.artifact.manifest.v1+json
   105  }