Delegate vsix manifest addition to storage impl

This will let them store extensions however they want rather than
assuming a specific structure.

Author: code-asher

storage/local.go

@@ -66,8 +66,8 @@ func (s *Local) AddExtension(ctx context.Context, vsix []byte) (*Extension, erro
 	}
 
 	// Copy the VSIX itself as well.
-	name := fmt.Sprintf("%s.%s-%s", identity.Publisher, identity.ID, identity.Version)
-	vsixName := fmt.Sprintf("%s.vsix", name)
+	id := extensionID(manifest)
+	vsixName := fmt.Sprintf("%s.vsix", id)
 	dst, err := os.OpenFile(filepath.Join(dir, vsixName), os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
 	if err != nil {
 		return nil, err
@@ -78,7 +78,7 @@ func (s *Local) AddExtension(ctx context.Context, vsix []byte) (*Extension, erro
 		return nil, err
 	}
 
-	ext := &Extension{ID: name, Location: dir}
+	ext := &Extension{ID: id, Location: dir}
 	for _, prop := range manifest.Metadata.Properties.Property {
 		if prop.Value == "" {
 			continue
@@ -163,7 +163,21 @@ func (s *Local) Manifest(ctx context.Context, publisher, extension, version stri
 	}
 	defer reader.Close()
 
-	return parseVSIXManifest(reader)
+	manifest, err := parseVSIXManifest(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	// The extension asset is not stored in the manifest.  Since we always store
+	// it next to the manifest using the publisher.name-version format we can set
+	// that as the path.
+	manifest.Assets.Asset = append(manifest.Assets.Asset, VSIXAsset{
+		Type:        VSIXAssetType,
+		Path:        fmt.Sprintf("%s.vsix", extensionID(manifest)),
+		Addressable: "true",
+	})
+
+	return manifest, nil
 }
 
 func (s *Local) WalkExtensions(ctx context.Context, fn func(manifest *VSIXManifest, versions []string) error) error {

storage/storage.go

@@ -109,7 +109,9 @@ type Storage interface {
 	// FileServer provides a handler for fetching extension repository files from
 	// a client.
 	FileServer() http.Handler
-	// Manifest returns the manifest for the provided extension version.
+	// Manifest returns the manifest for the provided extension version.  The
+	// extension asset (the VSIX) will always be added even if it does not exist
+	// in the manifest on disk.
 	Manifest(ctx context.Context, publisher, extension, version string) (*VSIXManifest, error)
 	// WalkExtensions applies a function over every extension providing the
 	// manifest for the latest version and a list of all available versions.  If
@@ -128,18 +130,6 @@ func parseVSIXManifest(reader io.Reader) (*VSIXManifest, error) {
 		return nil, err
 	}
 
-	// The extension asset is not stored in the manifest.  Since we always store
-	// it next to the manifest using the publisher.name-version format we can set
-	// that as the path.
-	vm.Assets.Asset = append(vm.Assets.Asset, VSIXAsset{
-		Type: VSIXAssetType,
-		Path: fmt.Sprintf("%s.%s-%s.vsix",
-			vm.Metadata.Identity.Publisher,
-			vm.Metadata.Identity.ID,
-			vm.Metadata.Identity.Version),
-		Addressable: "true",
-	})
-
 	return vm, nil
 }
 
@@ -183,3 +173,11 @@ func ReadVSIX(ctx context.Context, source string) ([]byte, error) {
 		N: 100 * 1000 * 1000, // 100 MB
 	})
 }
+
+// extensionID returns the full ID of an extension.
+func extensionID(manifest *VSIXManifest) string {
+	return fmt.Sprintf("%s.%s-%s",
+		manifest.Metadata.Identity.Publisher,
+		manifest.Metadata.Identity.ID,
+		manifest.Metadata.Identity.Version)
+}