Sanitize repo name when including in a layer title

These titles were previously including the filename as {org}/{repo}_{version} which means when clients download the layer they think it needs to be unwrapped into a folder called {org}.
This is not what we want, so we should instead rename the file as {org}-{repo}_{version}. e.g. from myorg/myrepo_myversion.zip to myorg-myrepo_myversion.zip

src/oci-container.ts

@@ -25,8 +25,9 @@ export function createActionPackageManifest(
   created: Date
 ): Manifest {
   const configLayer = createConfigLayer()
-  const tarLayer = createTarLayer(tarFile, repository, version)
-  const zipLayer = createZipLayer(zipFile, repository, version)
+  const sanitizedRepo = sanitizeRepository(repository)
+  const tarLayer = createTarLayer(tarFile, sanitizedRepo, version)
+  const zipLayer = createZipLayer(zipFile, sanitizedRepo, version)
 
   const manifest: Manifest = {
     schemaVersion: 2,
@@ -70,7 +71,7 @@ function createZipLayer(
     size: zipFile.size,
     digest: zipFile.sha256,
     annotations: {
-      'org.opencontainers.image.title': `${repository}-${version}.zip`
+      'org.opencontainers.image.title': `${repository}_${version}.zip`
     }
   }
 
@@ -87,9 +88,15 @@ function createTarLayer(
     size: tarFile.size,
     digest: tarFile.sha256,
     annotations: {
-      'org.opencontainers.image.title': `${repository}-${version}.tar.gz`
+      'org.opencontainers.image.title': `${repository}_${version}.tar.gz`
     }
   }
 
   return tarLayer
 }
+
+// Remove slashes so we can use the repository in a filename
+// repository usually includes the namespace too, e.g. my-org/my-repo
+function sanitizeRepository(repository: string): string {
+  return repository.replace('/', '-')
+}