refactor: write route.query via settings.write

I added a shallow parameter, because the query should not be extends, but should be replaced directly.

src/node/app/vscode.ts

@@ -134,7 +134,6 @@ export class VscodeHttpProvider extends HttpProvider {
           return { redirect: "/login", query: { to: this.options.base } }
         }
         try {
-          this.persistRouteQuery(request, route)
           return await this.getRoot(request, route)
         } catch (error) {
           const message = `<div>VS Code failed to load.</div> ${
@@ -166,13 +165,6 @@ export class VscodeHttpProvider extends HttpProvider {
     throw new HttpError("Not found", HttpCode.NotFound)
   }
 
-  private persistRouteQuery(request: http.IncomingMessage, route: Route): void {
-    const content = Object.keys(route.query).reduce((content, next) => {
-      return (content += `${next}=${route.query[next]}\n`)
-    }, "")
-    fs.writeFile(path.resolve(paths.data, "query"), content)
-  }
-
   private async getRoot(request: http.IncomingMessage, route: Route): Promise<HttpResponse> {
     const remoteAuthority = request.headers.host as string
     const { lastVisited } = await settings.read()
@@ -191,11 +183,15 @@ export class VscodeHttpProvider extends HttpProvider {
       }),
     ])
 
+    let promise = Promise.resolve()
     if (startPath) {
-      settings.write({
+      promise = settings.write({ lastVisited: startPath })
-        lastVisited: startPath,
-      })
     }
+    // `settings.write` depends on `settings.read` internally. To avoid race conditions, a promise is added here to synchronize.
+    promise.then(() => {
+      // the query should not be extends, but should be replaced directly.
+      settings.write({ query: route.query }, true)
+    })
 
     if (!this.isDev) {
       response.content = response.content.replace(/<!-- PROD_ONLY/g, "").replace(/END_PROD_ONLY -->/g, "")

src/node/settings.ts

@@ -2,6 +2,7 @@ import * as fs from "fs-extra"
 import * as path from "path"
 import { extend, paths } from "./util"
 import { logger } from "@coder/logger"
+import { Route } from "./http"
 
 export type Settings = { [key: string]: Settings | string | boolean | number }
 
@@ -31,9 +32,11 @@ export class SettingsProvider<T> {
    * Write settings combined with current settings. On failure log a warning.
    * Objects will be merged and everything else will be replaced.
    */
-  public async write(settings: Partial<T>): Promise<void> {
+  public async write(settings: Partial<T>, shallow?: boolean): Promise<void> {
     try {
-      await fs.writeFile(this.settingsPath, JSON.stringify(extend(await this.read(), settings), null, 2))
+      const oldSettings = await this.read()
+      const nextSettings = shallow ? Object.assign({}, oldSettings, settings) : extend(oldSettings, settings)
+      await fs.writeFile(this.settingsPath, JSON.stringify(nextSettings, null, 2))
     } catch (error) {
       logger.warn(error.message)
     }
@@ -55,6 +58,7 @@ export interface CoderSettings extends UpdateSettings {
     url: string
     workspace: boolean
   }
+  query: Route["query"]
 }
 
 /**