fix(electron-auto-updater): queue checkForUpdates

Closes #1045

Author: develar

nsis-auto-updater/package.json

@@ -1,6 +1,6 @@
 {
   "name": "electron-auto-updater",
-  "version": "0.8.2",
+  "version": "0.8.4",
   "description": "NSIS Auto Updater",
   "main": "out/nsis-auto-updater/src/main.js",
   "author": "Vladimir Krivosheev",
@@ -17,7 +17,7 @@
     "fs-extra-p": "^3.0.3",
     "js-yaml": "^3.7.0",
     "semver": "^5.3.0",
-    "source-map-support": "^0.4.6"
+    "source-map-support": "^0.4.8"
   },
   "typings": "./out/electron-auto-updater.d.ts"
 }

nsis-auto-updater/src/NsisUpdater.ts

@@ -29,6 +29,7 @@ export class NsisUpdater extends EventEmitter {
   private clientPromise: Promise<Provider<any>>
 
   private readonly untilAppReady: Promise<boolean>
+  private checkForUpdatesPromise: Promise<UpdateCheckResult> | null
 
   private readonly app: any
 
@@ -72,7 +73,22 @@ export class NsisUpdater extends EventEmitter {
     this.clientPromise = BluebirdPromise.resolve(createClient(value))
   }
 
-  async checkForUpdates(): Promise<UpdateCheckResult> {
+  checkForUpdates(): Promise<UpdateCheckResult> {
+    let checkForUpdatesPromise = this.checkForUpdatesPromise
+    if (checkForUpdatesPromise != null) {
+      return checkForUpdatesPromise
+    }
+
+    checkForUpdatesPromise = this._checkForUpdates()
+    this.checkForUpdatesPromise = checkForUpdatesPromise
+    const nullizePromise = () => this.checkForUpdatesPromise = null
+    checkForUpdatesPromise
+      .then(nullizePromise)
+      .catch(nullizePromise)
+    return checkForUpdatesPromise
+  }
+
+  private async _checkForUpdates(): Promise<UpdateCheckResult> {
     await this.untilAppReady
     this.emit("checking-for-update")
     try {

test/out/__snapshots__/nsisUpdaterTest.js.snap

@@ -1,3 +1,19 @@
+exports[`test checkForUpdates several times 1`] = `
+Object {
+  "name": "TestApp Setup 1.1.0.exe",
+  "sha2": "f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2",
+  "url": "https://develar.s3.amazonaws.com/test/TestApp Setup 1.1.0.exe",
+}
+`;
+
+exports[`test checkForUpdates several times 2`] = `
+Array [
+  "checking-for-update",
+  "update-available",
+  "update-downloaded",
+]
+`;
+
 exports[`test file url 1`] = `
 Object {
   "name": "TestApp Setup 1.1.0.exe",

test/src/nsisUpdaterTest.ts

@@ -111,6 +111,30 @@ test("file url generic - manual download", async () => {
   await assertThat(path.join(await updater.downloadUpdate())).isFile()
 })
 
+// https://github.com/electron-userland/electron-builder/issues/1045
+test("checkForUpdates several times", async () => {
+  const tmpDir = new TmpDir()
+  const testResourcesPath = await tmpDir.getTempFile("update-config")
+  await outputFile(path.join(testResourcesPath, "app-update.yml"), safeDump(<GenericServerOptions>{
+    provider: "generic",
+    url: "https://develar.s3.amazonaws.com/test",
+  }))
+  g.__test_resourcesPath = testResourcesPath
+  const updater: NsisUpdater = new NsisUpdaterClass()
+
+  const actualEvents = trackEvents(updater)
+
+  for (let i = 0; i < 10; i++) {
+    //noinspection JSIgnoredPromiseFromCall
+    updater.checkForUpdates()
+  }
+  const updateCheckResult = await updater.checkForUpdates()
+  expect(updateCheckResult.fileInfo).toMatchSnapshot()
+  await assertThat(path.join(await updateCheckResult.downloadPromise)).isFile()
+
+  expect(actualEvents).toMatchSnapshot()
+})
+
 test("file url github", async () => {
   const tmpDir = new TmpDir()
   const testResourcesPath = await tmpDir.getTempFile("update-config")