Self-Updater Detection
Electron App Detection
AppPorts identifies Electron apps through the following three detection conditions (checked in order of priority, short-circuit evaluation):
| # | Detection Item | Path / Pattern |
|---|---|---|
| 1 | Electron Framework | Contents/Frameworks/Electron Framework.framework directory exists |
| 2 | Electron Helper variants | Entries containing Electron Helper in name exist under Contents/Frameworks/ |
| 3 | Info.plist identifier keys | ElectronDefaultApp or electron key exists in Contents/Info.plist |
Electron Self-Update Detection
Additionally checks for the existence of Contents/Resources/app-update.yml file (configuration file for electron-updater). If present, the Electron app is marked as having self-update capability.
Sparkle App Detection
AppPorts identifies Sparkle apps through the following three detection conditions:
| # | Detection Item | Path / Pattern |
|---|---|---|
| 1 | Sparkle framework | Contents/Frameworks/Sparkle.framework or Contents/Frameworks/Squirrel.framework exists |
| 2 | Updater binary files | Files matching shipit, autoupdate, updater, update exist under Contents/MacOS/ or Contents/Frameworks/ |
| 3 | Info.plist Sparkle keys | Any of the following keys exist in Contents/Info.plist: SUFeedURL, SUPublicDSAKeyFile, SUPublicEDKey, SUScheduledCheckInterval, SUAllowsAutomaticUpdates |
⚠️ Special Handling for Electron Apps
When an app has been identified as an Electron app, detection condition #2 (updater binary files) is skipped to avoid false positives from electron-updater's updater binary being detected as Sparkle.
Hybrid Electron + Sparkle Apps
Some apps contain both Electron framework and Sparkle updater. AppPorts detects both flags independently, allowing isElectron and isSparkle to both be true.
Detection Logic
isElectron = satisfies any of the three Electron detection conditions
isSparkle = satisfies any of the three Sparkle detection conditions (Electron apps skip condition #2)The two flags are independent and can both be true simultaneously.
Post-Migration Behavior
| Attribute | Determination Condition |
|---|---|
hasSelfUpdater | isSparkle or (isElectron and app-update.yml exists) or custom updater exists |
needsLock | isSparkle or (isElectron and app-update.yml exists) |
When needsLock is true, AppPorts executes chflags -R uchg (setting immutable flag) on the external storage app after migration completes, preventing self-updaters from deleting or modifying the external copy.
Custom Updater Detection
For native self-updating apps that are neither Sparkle nor Electron (e.g., Chrome, Edge, Parallels), AppPorts identifies them through the following patterns:
| Detection Path | Matching Pattern | Typical Apps |
|---|---|---|
Contents/Library/LaunchServices/ | Filename contains update | Chrome, Edge, Thunderbird |
Contents/MacOS/ | Binary filename contains update or upgrade (excluding electron) | Parallels, Thunderbird |
Contents/SharedSupport/ | Filename contains update | WPS Office |
Contents/Info.plist | KSProductID key exists | Google Keystone (Chrome) |
Legacy Strategy Identification
When restoring or unlinking, AppPorts needs to identify legacy entries created by older versions:
| Local Structure Characteristic | Identified As |
|---|---|
| Root path is a symbolic link | wholeAppSymlink |
Contents/ is a symbolic link | deepContentsWrapper |
Contents/Info.plist is a symbolic link | wholeAppSymlink (legacy Sparkle hybrid scheme) |
Contents/Frameworks/ is a symbolic link | wholeAppSymlink (legacy Electron hybrid scheme) |
Contents/MacOS/launcher exists | stubPortal |
| None of the above match | Not managed by AppPorts |