feat: add option to opt out non sdk metadata (#283)

context:
https://statsigcommunity.slack.com/archives/C01RAKM10TD/p1718750620298129?thread_ts=1718606236.716329&cid=C01RAKM10TD


test: add UT

Sources/Statsig/DeviceEnvironment.swift

@@ -52,12 +52,28 @@ struct DeviceEnvironment {
     static func get(_ overrideStableID: String? = nil) -> [String: String?] {
         return instance.get(overrideStableID)
     }
+
+    static func getSDKMetadata(_ overrideStableID: String? = nil) -> [String: String?] {
+        return instance.getSDKMetadata(overrideStableID)
+    }
 
     static func explicitGet(_ overrideStableID: String? = nil) -> [String: String] {
         return instance.get(overrideStableID).mapValues { val in
             return val ?? ""
         }
     }
+
+    private func getSDKMetadata(_ overrideStableID: String? = nil) -> [String: String?] {
+        lock.lock()
+        defer { lock.unlock() }
+
+        return [
+            "sdkType": DeviceEnvironment.sdkType,
+            "sdkVersion": DeviceEnvironment.sdkVersion,
+            "sessionID": sessionID,
+            "stableID": getStableID(overrideStableID)
+        ]
+    }
 
     private func get(_ overrideStableID: String? = nil) -> [String: String?] {
         lock.lock()

Sources/Statsig/StatsigUser.swift

@@ -43,6 +43,12 @@ public struct StatsigUser {
      Any value you wish to use in evaluation, but not have logged with events can be stored in this field.
      */
     public let privateAttributes: [String: StatsigUserCustomTypeConvertible]?
+
+    /**
+     Controls whether non-SDK-type SDK version metadata should be excluded or included.
+     Setting this option to `true` will exclude metadata related to non-SDK-type SDK versions. By default, this option is set to `false`, meaning all metadata is included.
+     */
+    public var optOutNonSdkMetadata: Bool?
 
     /**
      Any Custom IDs to associated with the user.
@@ -62,6 +68,7 @@ public struct StatsigUser {
                 appVersion: String? = nil,
                 custom: [String: StatsigUserCustomTypeConvertible]? = nil,
                 privateAttributes: [String: StatsigUserCustomTypeConvertible]? = nil,
+                optOutNonSdkMetadata: Bool? = false,
                 customIDs: [String: String]? = nil)
     {
         self.userID = userID
@@ -71,6 +78,7 @@ public struct StatsigUser {
         self.locale = locale
         self.appVersion = appVersion
         self.customIDs = customIDs
+        self.optOutNonSdkMetadata = optOutNonSdkMetadata
 
         if let custom = custom, JSONSerialization.isValidJSONObject(custom) {
             self.custom = custom
@@ -89,11 +97,20 @@ public struct StatsigUser {
             }
             self.privateAttributes = nil
         }
-        self.deviceEnvironment = DeviceEnvironment.get()
+
+        if (self.optOutNonSdkMetadata ?? false) {
+            self.deviceEnvironment = DeviceEnvironment.getSDKMetadata()
+        } else {
+            self.deviceEnvironment = DeviceEnvironment.get()
+        }
     }
 
     mutating func setStableID(_ overrideStableID: String) {
-        self.deviceEnvironment = DeviceEnvironment.get(overrideStableID)
+        if (self.optOutNonSdkMetadata ?? false) {
+            self.deviceEnvironment = DeviceEnvironment.getSDKMetadata(overrideStableID)
+        } else {
+            self.deviceEnvironment = DeviceEnvironment.get(overrideStableID)
+        }
     }
 
     func toDictionary(forLogging: Bool) -> [String: Any?] {

Tests/StatsigTests/StatsigUserSpec.swift

@@ -24,6 +24,17 @@ class StatsigUserSpec: BaseSpec {
                 expect(validEmptyUser.deviceEnvironment).toNot(beNil())
                 expect(validEmptyUser.customIDs).to(beNil())
             }
+
+            it("only return sdk related medatada if opt out non sdk metadata") {
+                let validUserOptOutNonSdkMetadata = StatsigUser(optOutNonSdkMetadata: true)
+
+                let deviceEnvironment = validUserOptOutNonSdkMetadata.deviceEnvironment
+                expect(deviceEnvironment["sdkVersion"]) == "1.44.0"
+                expect(deviceEnvironment["sdkType"]) == "ios-client"
+                expect(deviceEnvironment["sessionID"]).toNot(beNil())
+                expect(deviceEnvironment["stableID"]).toNot(beNil())
+                expect(deviceEnvironment.count) == 4
+            }
 
             it("is a valid user with ID provided") {
                 let validUserWithID = StatsigUser(userID: "12345")