Fix vim plugin: cancel pending completion request when make a new completion request. (#114)

clients/vim/autoload/tabby.vim

@@ -176,6 +176,7 @@ function! s:GetCompletion(id)
       \ prompt: s:GetPrompt(),
       \ language: s:GetLanguage(),
       \ }],
+    \ cancelPendingRequest: v:true,
     \ }, #{
     \ callback: function('s:HandleCompletion', [a:id]),
     \ })

clients/vim/node_scripts/src/index.ts

@@ -1,6 +1,6 @@
 import { TabbyClient } from "./TabbyClient";
 import { getFunction } from "./utils";
-import { CancelablePromise, ApiError } from "./generated";
+import { CancelablePromise, CancelError, ApiError } from "./generated";
 const tabby = TabbyClient.getInstance();
 
 interface VimRequest {
@@ -8,6 +8,7 @@ interface VimRequest {
   1: {
     func: string;
     args?: any;
+    cancelPendingRequest?: boolean; // cancel pending request that called the same API
   };
 }
 
@@ -16,6 +17,8 @@ interface VimResponse {
   1: any; // Response data
 }
 
+const pendingPromise : { [key: string]: CancelablePromise<any> } = {};
+
 process.stdin.on("data", async (data) => {
   try {
     const req: VimRequest = JSON.parse(data.toString());
@@ -26,16 +29,24 @@ process.stdin.on("data", async (data) => {
       const result = func(...args);
       if (result instanceof CancelablePromise && req[1].func.startsWith("api.")) {
         // Async API calls
+        if (req[1].cancelPendingRequest && pendingPromise[req[1].func]) {
+          pendingPromise[req[1].func].cancel();
+        }
+        pendingPromise[req[1].func] = result;
         resp[1] = await result
           .then((response: any) => {
             tabby.changeStatus("ready");
             return response;
           })
+          .catch((e: CancelError) => {
+            return null;
+          })
           .catch((e: ApiError) => {
             process.stderr.write(JSON.stringify(e, Object.getOwnPropertyNames(e)) + "\n");
             tabby.changeStatus("disconnected");
             return null;
           });
+        pendingPromise[req[1].func] = null;
       } else if (result instanceof Promise) {
         // Async calls (non-API)
         resp[1] = await result;