feat(electron-updater): Make it possible to "auto-downgrade" the appl…

…ication on channel change

Close electron-userland#1149

packages/electron-updater/src/AppUpdater.ts

@@ -6,7 +6,7 @@ import { EventEmitter } from "events"
 import { readFile } from "fs-extra-p"
 import { safeLoad } from "js-yaml"
 import * as path from "path"
-import { gt as isVersionGreaterThan, valid as parseVersion } from "semver"
+import { eq as isVersionsEqual, gt as isVersionGreaterThan, prerelease as getVersionPreleaseComponents, valid as parseVersion } from "semver"
 import "source-map-support/register"
 import { FileInfo, Provider, UpdateCheckResult, UpdaterSignal } from "./api"
 import { BintrayProvider } from "./BintrayProvider"
@@ -25,10 +25,23 @@ export interface Logger {
 
 export abstract class AppUpdater extends EventEmitter {
   /**
-   * Automatically download an update when it is found.
+   * Whether to automatically download an update when it is found.
    */
   autoDownload = true
 
+  /**
+   * *GitHub provider only.* Whether to allow update to pre-release versions. Defaults to `true` if application version contains prerelease components (e.g. `0.12.1-alpha.1`, here `alpha` is a prerelease component), otherwise `false`.
+   *
+   * If `true`, downgrade will be allowed (`allowDowngrade` will be set to `true`).
+   */
+  allowPrerelease = false
+
+  /**
+   * Whether to allow version downgrade (when a user from the beta channel wants to go back to the stable channel).
+   * Defaults to `true` if application version contains prerelease components (e.g. `0.12.1-alpha.1`, here `alpha` is a prerelease component), otherwise `false`.
+   */
+  allowDowngrade = false
+
   /**
    *  The request headers.
    */
@@ -64,7 +77,9 @@ export abstract class AppUpdater extends EventEmitter {
   protected versionInfo: VersionInfo | null
   private fileInfo: FileInfo | null
 
-  constructor(options: PublishConfiguration | null | undefined) {
+  private currentVersion: string
+
+  constructor(options: PublishConfiguration | null | undefined, app?: any) {
     super()
 
     this.on("error", (error: Error) => {
@@ -73,8 +88,8 @@ export abstract class AppUpdater extends EventEmitter {
       }
     })
 
-    if ((<any>global).__test_app != null) {
-      this.app = (<any>global).__test_app
+    if (app != null || (<any>global).__test_app != null) {
+      this.app = app || (<any>global).__test_app
       this.untilAppReady = BluebirdPromise.resolve()
     }
     else {
@@ -96,6 +111,16 @@ export abstract class AppUpdater extends EventEmitter {
       })
     }
 
+    const currentVersionString = this.app.getVersion()
+    this.currentVersion = parseVersion(currentVersionString)
+    if (this.currentVersion == null) {
+      throw new Error(`App version is not valid semver version: "${currentVersionString}`)
+    }
+
+    const versionPrereleaseComponent = getVersionPreleaseComponents(this.currentVersion)
+    this.allowDowngrade = versionPrereleaseComponent != null && versionPrereleaseComponent.length > 0
+    this.allowPrerelease = this.allowDowngrade
+
     if (options != null) {
       this.setFeedURL(options)
     }
@@ -171,16 +196,10 @@ export abstract class AppUpdater extends EventEmitter {
       throw new Error(`Latest version (from update server) is not valid semver version: "${latestVersion}`)
     }
 
-    const currentVersionString = this.app.getVersion()
-    const currentVersion = parseVersion(currentVersionString)
-    if (currentVersion == null) {
-      throw new Error(`App version is not valid semver version: "${currentVersion}`)
-    }
-
-    if (!isVersionGreaterThan(latestVersion, currentVersion)) {
+    if (this.allowDowngrade ? isVersionsEqual(latestVersion, this.currentVersion) : !isVersionGreaterThan(latestVersion, this.currentVersion)) {
       this.updateAvailable = false
       if (this.logger != null) {
-        this.logger.info(`Update for version ${currentVersionString} is not available (latest version: ${versionInfo.version})`)
+        this.logger.info(`Update for version ${this.currentVersion} is not available (latest version: ${versionInfo.version}, downgrade is ${this.allowDowngrade ? "allowed" : "disallowed"}.`)
       }
       this.emit("update-not-available", versionInfo)
       return {

packages/electron-updater/src/NsisUpdater.ts

@@ -14,8 +14,8 @@ export class NsisUpdater extends AppUpdater {
   private quitAndInstallCalled = false
   private quitHandlerAdded = false
 
-  constructor(options?: PublishConfiguration) {
-    super(options)
+  constructor(options?: PublishConfiguration, app?: any) {
+    super(options, app)
   }
 
   /**

test/out/__snapshots__/nsisUpdaterTest.js.snap

@@ -20,6 +20,16 @@ Array [
 ]
 `;
 
+exports[`downgrade (allowed) 1`] = `
+Object {
+  "name": "TestApp Setup 1.1.0.exe",
+  "sha2": "01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b",
+  "url": "https://dl.bintray.com/actperepo/generic/TestApp Setup 1.1.0.exe",
+}
+`;
+
+exports[`downgrade (disallowed) 1`] = `undefined`;
+
 exports[`file url 1`] = `
 Object {
   "name": "TestApp Setup 1.1.0.exe",

test/src/nsisUpdaterTest.ts

@@ -41,18 +41,8 @@ test("check updates - no versions at all", async () => {
   await assertThat(updater.checkForUpdates()).throws()
 })
 
-// test("cannot find suitable file for version", async () => {
-//   const updater = new NsisUpdater(<BintrayOptions>{
-//     provider: "bintray",
-//     owner: "actperepo",
-//     package: "incorrect-file-version",
-//   })
-//
-//   await assertThat(updater.checkForUpdates()).throws()
-// })
-
-test("file url", async () => {
-  const updater = new NsisUpdater()
+async function testUpdateFromBintray(app: any) {
+  const updater = new NsisUpdater(null, app)
   updater.updateConfigPath = await writeUpdateConfig(<BintrayOptions>{
     provider: "bintray",
     owner: "actperepo",
@@ -71,9 +61,58 @@ test("file url", async () => {
   expect(updateCheckResult.fileInfo).toMatchSnapshot()
   await assertThat(path.join(await updateCheckResult.downloadPromise)).isFile()
 
+  expect(actualEvents).toEqual(expectedEvents)
+}
+test("file url", () => testUpdateFromBintray(null))
+
+test("downgrade (disallowed)", async () => {
+  const updater = new NsisUpdater(null, {
+      getVersion: function () {
+        return "2.0.0"
+      },
+
+      getAppPath: function () {
+      },
+
+      on: function () {
+        // ignored
+      },
+    }
+  )
+  updater.updateConfigPath = await writeUpdateConfig(<BintrayOptions>{
+    provider: "bintray",
+    owner: "actperepo",
+    package: "TestApp",
+  })
+
+  const actualEvents: Array<string> = []
+  const expectedEvents = ["checking-for-update", "update-not-available"]
+  for (const eventName of expectedEvents) {
+    updater.addListener(eventName, () => {
+      actualEvents.push(eventName)
+    })
+  }
+
+  const updateCheckResult = await updater.checkForUpdates()
+  expect(updateCheckResult.fileInfo).toMatchSnapshot()
+  expect(updateCheckResult.downloadPromise).toBeUndefined()
+
   expect(actualEvents).toEqual(expectedEvents)
 })
 
+test("downgrade (allowed)", () => testUpdateFromBintray({
+  getVersion: function () {
+    return "2.0.0-beta.1"
+  },
+
+  getAppPath: function () {
+  },
+
+  on: function () {
+    // ignored
+  },
+}))
+
 test("file url generic", async () => {
   const updater = new NsisUpdater()
   updater.updateConfigPath = await writeUpdateConfig(<GenericServerOptions>{