Use appropriate storage location + migrate events (#399)

* Use proper directory for storage + migrate

* Remove dead code.

* tightened up migration code

Author: bsneed

Sources/Segment/State.swift

@@ -149,7 +149,6 @@ struct System: State {
 
         func reduce(state: System) -> System {
             var waitingPlugins = state.waitingPlugins
-            let countBefore = waitingPlugins.count
             waitingPlugins.removeAll { p in
                 return plugin === p
             }

Sources/Segment/Utilities/Utils.swift

@@ -75,17 +75,45 @@ extension Optional: Flattenable {
 }
 
 internal func eventStorageDirectory(writeKey: String) -> URL {
-    #if (os(iOS) || os(watchOS)) && !targetEnvironment(macCatalyst)
-    let searchPathDirectory = FileManager.SearchPathDirectory.documentDirectory
-    #else
-    let searchPathDirectory = FileManager.SearchPathDirectory.cachesDirectory
-    #endif
+    let urls = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)
+    let appSupportURL = urls[0]
+    let segmentURL = appSupportURL.appendingPathComponent("segment/\(writeKey)/")
+    
+    // Handle one-time migration from old locations
+    migrateFromOldLocations(writeKey: writeKey, to: segmentURL)
 
-    let urls = FileManager.default.urls(for: searchPathDirectory, in: .userDomainMask)
-    let docURL = urls[0]
-    let segmentURL = docURL.appendingPathComponent("segment/\(writeKey)/")
     // try to create it, will fail if already exists, nbd.
     // tvOS, watchOS regularly clear out data.
     try? FileManager.default.createDirectory(at: segmentURL, withIntermediateDirectories: true, attributes: nil)
     return segmentURL
 }
+
+private func migrateFromOldLocations(writeKey: String, to newLocation: URL) {
+    let fm = FileManager.default
+    
+    // Get the parent of where our new segment directory should live
+    let appSupportURL = fm.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
+    let newSegmentDir = appSupportURL.appendingPathComponent("segment")
+    
+    // If segment dir already exists in app support, we're done
+    guard !fm.fileExists(atPath: newSegmentDir.path) else { return }
+    
+    // Only check the old location that was actually used on this platform
+    #if (os(iOS) || os(watchOS)) && !targetEnvironment(macCatalyst)
+    let oldSearchPath = FileManager.SearchPathDirectory.documentDirectory
+    #else
+    let oldSearchPath = FileManager.SearchPathDirectory.cachesDirectory
+    #endif
+    
+    guard let oldBaseURL = fm.urls(for: oldSearchPath, in: .userDomainMask).first else { return }
+    let oldSegmentDir = oldBaseURL.appendingPathComponent("segment")
+    
+    guard fm.fileExists(atPath: oldSegmentDir.path) else { return }
+    
+    do {
+        try fm.moveItem(at: oldSegmentDir, to: newSegmentDir)
+        Analytics.segmentLog(message: "Migrated analytics data from \(oldSegmentDir.path)", kind: .debug)
+    } catch {
+        Analytics.segmentLog(message: "Failed to migrate from \(oldSegmentDir.path): \(error)", kind: .error)
+    }
+}

Tests/Segment-Tests/Storage_Tests.swift

@@ -137,7 +137,10 @@ class StorageTests: XCTestCase {
     }
 
     func testFilePrepAndFinish() {
-        let analytics = Analytics(configuration: Configuration(writeKey: "test"))
+        let config = Configuration(writeKey: "test")
+            .storageMode(.diskAtURL(URL(fileURLWithPath: NSTemporaryDirectory())))
+        let analytics = Analytics(configuration: config)
+        
         analytics.storage.hardReset(doYouKnowHowToUseThis: true)
 
         analytics.waitUntilStarted()
@@ -302,4 +305,45 @@ class StorageTests: XCTestCase {
         let remaining = analytics.storage.read(.events)
         XCTAssertNil(remaining)
     }
+    
+    func testMigrationFromOldLocation() {
+        let writeKey = "test-migration"
+        let fm = FileManager.default
+        
+        // Clean slate
+        let appSupportURL = fm.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
+        let newSegmentDir = appSupportURL.appendingPathComponent("segment")
+        try? fm.removeItem(at: newSegmentDir)
+        
+        // Create fake old data in the platform-specific old location
+        #if (os(iOS) || os(watchOS)) && !targetEnvironment(macCatalyst)
+        let oldSearchPath = FileManager.SearchPathDirectory.documentDirectory
+        #else
+        let oldSearchPath = FileManager.SearchPathDirectory.cachesDirectory
+        #endif
+        
+        let oldBaseURL = fm.urls(for: oldSearchPath, in: .userDomainMask)[0]
+        let oldSegmentDir = oldBaseURL.appendingPathComponent("segment/\(writeKey)")
+        try! fm.createDirectory(at: oldSegmentDir, withIntermediateDirectories: true, attributes: nil)
+        
+        // Write some fake event files
+        let testFile1 = oldSegmentDir.appendingPathComponent("0-segment-events.temp")
+        let testFile2 = oldSegmentDir.appendingPathComponent("1-segment-events.temp")
+        try! "fake event data 1".write(to: testFile1, atomically: true, encoding: .utf8)
+        try! "fake event data 2".write(to: testFile2, atomically: true, encoding: .utf8)
+        
+        // Trigger migration
+        let resultURL = eventStorageDirectory(writeKey: writeKey)
+        
+        // Verify migration worked
+        XCTAssertTrue(fm.fileExists(atPath: resultURL.path))
+        XCTAssertTrue(fm.fileExists(atPath: resultURL.appendingPathComponent("0-segment-events.temp").path))
+        XCTAssertTrue(fm.fileExists(atPath: resultURL.appendingPathComponent("1-segment-events.temp").path))
+        
+        // Verify old directory is gone
+        XCTAssertFalse(fm.fileExists(atPath: oldSegmentDir.path))
+        
+        // Clean up
+        try? fm.removeItem(at: newSegmentDir)
+    }
 }