Support fetching remote reusable workflows

actions-languageserver/src/connection.ts

@@ -20,6 +20,7 @@ import {getClient} from "./client";
 import {Commands} from "./commands";
 import {contextProviders} from "./context-providers";
 import {descriptionProvider} from "./description-provider";
+import {getFileProvider} from "./file-provider";
 import {InitializationOptions, RepositoryContext} from "./initializationOptions";
 import {onCompletion} from "./on-completion";
 import {TTLCache} from "./utils/cache";
@@ -106,7 +107,8 @@ export function initConnection(connection: Connection) {
         }
 
         return undefined;
-      }
+      },
+      fileProvider: getFileProvider(client, cache)
     };
     const result = await validate(textDocument, config);
 

actions-languageserver/src/file-provider.ts

@@ -0,0 +1,54 @@
+import {File} from "@github/actions-workflow-parser/workflows/file";
+import {FileProvider} from "@github/actions-workflow-parser/workflows/file-provider";
+import {fileIdentifier} from "@github/actions-workflow-parser/workflows/file-reference";
+import {Octokit} from "@octokit/rest";
+import {TTLCache} from "./utils/cache";
+
+export function getFileProvider(client: Octokit | undefined, cache: TTLCache): FileProvider | undefined {
+  if (!client) {
+    return undefined;
+  }
+
+  return {
+    getFileContent: async (ref): Promise<File> => {
+      if (!("repository" in ref)) {
+        throw new Error("Only remote file references are supported right now");
+      }
+
+      return await cache.get(`file-content-${fileIdentifier(ref)}`, undefined, () =>
+        fetchWorkflowFile(client, ref.owner, ref.repository, ref.path, ref.version)
+      );
+    }
+  };
+}
+
+async function fetchWorkflowFile(
+  client: Octokit,
+  owner: string,
+  repo: string,
+  path: string,
+  version: string
+): Promise<File> {
+  const resp = await client.repos.getContent({
+    owner,
+    repo,
+    path,
+    ref: version
+  });
+
+  // https://docs.github.com/rest/repos/contents?apiVersion=2022-11-28
+  // Ignore directories (array of files) and non-file content
+  if (
+    resp.data === undefined ||
+    Array.isArray(resp.data) ||
+    resp.data.type !== "file" ||
+    resp.data.content === undefined
+  ) {
+    throw new Error("Not a file");
+  }
+
+  return {
+    name: path,
+    content: Buffer.from(resp.data.content, "base64").toString("utf8")
+  };
+}