feat: Implement withContext (#89)

* Implement withContext * Add ConfidenceContextProvider protocol * Remove context on child instance * Remove clear from Contextual
spotify · Apr 9, 2024 · d0dddee · d0dddee
1 parent 56f8130
commit d0dddee
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Showing 5 changed files with 230 additions and 20 deletions.
diff --git a/Sources/Confidence/Confidence.swift b/Sources/Confidence/Confidence.swift
@@ -1,45 +1,64 @@
 import Foundation
 
 public class Confidence: ConfidenceEventSender {
-    public var context: ConfidenceStruct
+    private let parent: ConfidenceContextProvider?
+    private var context: ConfidenceStruct
     public let clientSecret: String
     public var timeout: TimeInterval
     public var region: ConfidenceRegion
     public var initializationStrategy: InitializationStrategy
+    private var removedContextKeys: Set<String> = Set()
 
-    init(
+    required public init(
         clientSecret: String,
         timeout: TimeInterval,
         region: ConfidenceRegion,
-        initializationStrategy: InitializationStrategy
+        initializationStrategy: InitializationStrategy,
+        context: ConfidenceStruct = [:],
+        parent: ConfidenceEventSender? = nil
     ) {
-        self.context = [:]
         self.clientSecret = clientSecret
         self.timeout = timeout
         self.region = region
         self.initializationStrategy = initializationStrategy
+        self.context = context
+        self.parent = parent
     }
 
     // TODO: Implement actual event uploading to the backend
     public func send(definition: String, payload: ConfidenceStruct) {
         print("Sending: \"\(definition)\".\nMessage: \(payload)\nContext: \(context)")
     }
 
+
+    public func getContext() -> ConfidenceStruct {
+        let parentContext = parent?.getContext() ?? [:]
+        var reconciledCtx = parentContext.filter {
+            !removedContextKeys.contains($0.key)
+        }
+        self.context.forEach { entry in
+            reconciledCtx.updateValue(entry.value, forKey: entry.key)
+        }
+        return reconciledCtx
+    }
+
     public func updateContextEntry(key: String, value: ConfidenceValue) {
         context[key] = value
     }
 
     public func removeContextEntry(key: String) {
         context.removeValue(forKey: key)
+        removedContextKeys.insert(key)
     }
 
-    public func clearContext() {
-        context = [:]
-    }
-
-    // TODO: Implement creation of child instances
     public func withContext(_ context: ConfidenceStruct) -> Self {
-        return self
+        return Self.init(
+            clientSecret: clientSecret,
+            timeout: timeout,
+            region: region,
+            initializationStrategy: initializationStrategy,
+            context: context,
+            parent: self)
     }
 }
 

diff --git a/Sources/Confidence/ConfidenceContextProvider.swift b/Sources/Confidence/ConfidenceContextProvider.swift
@@ -0,0 +1,6 @@
+import Foundation
+
+/// A Contextual implementer returns the current context
+public protocol ConfidenceContextProvider {
+    func getContext() -> ConfidenceStruct
+}
diff --git a/Sources/Confidence/Contextual.swift b/Sources/Confidence/Contextual.swift
@@ -1,14 +1,14 @@
 import Foundation
 
-/// A Contextual implementer maintains context data and can create child instances
+/// A Contextual implementer maintains local context data and can create child instances
 /// that can still access their parent's data
-public protocol Contextual {
-    var context: ConfidenceStruct { get set }
-
+/// Each ConfidenceContextProvider returns local data reconciled with parents' data. Local data has precedence
+public protocol Contextual: ConfidenceContextProvider {
+    /// Adds/override entry to local data
     func updateContextEntry(key: String, value: ConfidenceValue)
+    /// Removes entry from local data
+    /// It hides entries with this key from parents' data (without modifying parents' data)
     func removeContextEntry(key: String)
-    func clearContext()
-    /// Creates a child Contextual instance that still has access
-    /// to its parent context
+    /// Creates a child Contextual instance that maintains access to its parent's data
     func withContext(_ context: ConfidenceStruct) -> Self
 }
diff --git a/Tests/ConfidenceProviderTests/ConfidenceFeatureProviderTest.swift b/Tests/ConfidenceProviderTests/ConfidenceFeatureProviderTest.swift
@@ -913,7 +913,7 @@ class ConfidenceFeatureProviderTest: XCTestCase {
         {
             provider.initialize(initialContext: MutableContext(targetingKey: "user1"))
             wait(for: [readyExpectation], timeout: 5)
-            let context = confidence.context
+            let context = confidence.getContext()
             let expected = [
                 "open_feature": ConfidenceValue(structure: ["targeting_key": ConfidenceValue(string: "user1")])
             ]
@@ -936,11 +936,13 @@ class ConfidenceFeatureProviderTest: XCTestCase {
             })
         {
             let ctx1 = MutableContext(targetingKey: "user1")
-            let ctx2 = MutableContext(targetingKey: "user1", structure: MutableStructure(attributes: ["active": Value.boolean(true)]))
+            let ctx2 = MutableContext(
+                targetingKey: "user1",
+                structure: MutableStructure(attributes: ["active": Value.boolean(true)]))
             provider.initialize(initialContext: ctx1)
             provider.onContextSet(oldContext: ctx1, newContext: ctx2)
             wait(for: [readyExpectation], timeout: 5)
-            let context = confidence.context
+            let context = confidence.getContext()
             let expected = [
                 "open_feature": ConfidenceValue(structure: [
                     "targeting_key": ConfidenceValue(string: "user1"),

diff --git a/Tests/ConfidenceTests/ConfidenceTests.swift b/Tests/ConfidenceTests/ConfidenceTests.swift
@@ -0,0 +1,183 @@
+import Confidence
+import XCTest
+
+final class ConfidenceTests: XCTestCase {
+    func testWithContext() {
+        let confidenceParent = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        let confidenceChild: ConfidenceEventSender = confidenceParent.withContext(
+            ["k2": ConfidenceValue(string: "v2")]
+        )
+        let expected = [
+            "k1": ConfidenceValue(string: "v1"),
+            "k2": ConfidenceValue(string: "v2")
+        ]
+        XCTAssertEqual(confidenceChild.getContext(), expected)
+    }
+
+    func testWithContextUpdateParent() {
+        let confidenceParent = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        let confidenceChild: ConfidenceEventSender = confidenceParent.withContext(
+            ["k2": ConfidenceValue(string: "v2")]
+        )
+        confidenceParent.updateContextEntry(
+            key: "k3",
+            value: ConfidenceValue(string: "v3"))
+        let expected = [
+            "k1": ConfidenceValue(string: "v1"),
+            "k2": ConfidenceValue(string: "v2"),
+            "k3": ConfidenceValue(string: "v3"),
+        ]
+        XCTAssertEqual(confidenceChild.getContext(), expected)
+    }
+
+    func testUpdateLocalContext() {
+        let confidence = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        confidence.updateContextEntry(
+            key: "k1",
+            value: ConfidenceValue(string: "v3"))
+        let expected = [
+            "k1": ConfidenceValue(string: "v3"),
+        ]
+        XCTAssertEqual(confidence.getContext(), expected)
+    }
+
+    func testUpdateLocalContextWithoutOverride() {
+        let confidenceParent = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        let confidenceChild: ConfidenceEventSender = confidenceParent.withContext(
+            ["k2": ConfidenceValue(string: "v2")]
+        )
+        confidenceChild.updateContextEntry(
+            key: "k2",
+            value: ConfidenceValue(string: "v4"))
+        let expected = [
+            "k1": ConfidenceValue(string: "v1"),
+            "k2": ConfidenceValue(string: "v4"),
+        ]
+        XCTAssertEqual(confidenceChild.getContext(), expected)
+    }
+
+    func testUpdateParentContextWithOverride() {
+        let confidenceParent = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        let confidenceChild: ConfidenceEventSender = confidenceParent.withContext(
+            ["k2": ConfidenceValue(string: "v2")]
+        )
+        confidenceParent.updateContextEntry(
+            key: "k2",
+            value: ConfidenceValue(string: "v4"))
+        let expected = [
+            "k1": ConfidenceValue(string: "v1"),
+            "k2": ConfidenceValue(string: "v2"),
+        ]
+        XCTAssertEqual(confidenceChild.getContext(), expected)
+    }
+
+    func testRemoveContextEntry() {
+        let confidence = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: [
+                "k1": ConfidenceValue(string: "v1"),
+                "k2": ConfidenceValue(string: "v2")
+            ]
+        )
+        confidence.removeContextEntry(key: "k2")
+        let expected = [
+            "k1": ConfidenceValue(string: "v1")
+        ]
+        XCTAssertEqual(confidence.getContext(), expected)
+    }
+
+    func testRemoveContextEntryFromParent() {
+        let confidenceParent = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        let confidenceChild: ConfidenceEventSender = confidenceParent.withContext(
+            ["k2": ConfidenceValue(string: "v2")]
+        )
+        confidenceChild.removeContextEntry(key: "k1")
+        let expected = [
+            "k2": ConfidenceValue(string: "v2")
+        ]
+        XCTAssertEqual(confidenceChild.getContext(), expected)
+    }
+
+    func testRemoveContextEntryFromParentAndChild() {
+        let confidenceParent = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        let confidenceChild: ConfidenceEventSender = confidenceParent.withContext(
+            [
+                "k2": ConfidenceValue(string: "v2"),
+                "k1": ConfidenceValue(string: "v3"),
+            ]
+        )
+        confidenceChild.removeContextEntry(key: "k1")
+        let expected = [
+            "k2": ConfidenceValue(string: "v2")
+        ]
+        XCTAssertEqual(confidenceChild.getContext(), expected)
+    }
+
+    func testRemoveContextEntryFromParentAndChildThenUpdate() {
+        let confidenceParent = Confidence.init(
+            clientSecret: "",
+            timeout: TimeInterval(),
+            region: .europe,
+            initializationStrategy: .activateAndFetchAsync,
+            context: ["k1": ConfidenceValue(string: "v1")]
+        )
+        let confidenceChild: ConfidenceEventSender = confidenceParent.withContext(
+            [
+                "k2": ConfidenceValue(string: "v2"),
+                "k1": ConfidenceValue(string: "v3"),
+            ]
+        )
+        confidenceChild.removeContextEntry(key: "k1")
+        confidenceChild.updateContextEntry(key: "k1", value: ConfidenceValue(string: "v4"))
+        let expected = [
+            "k2": ConfidenceValue(string: "v2"),
+            "k1": ConfidenceValue(string: "v4"),
+        ]
+        XCTAssertEqual(confidenceChild.getContext(), expected)
+    }
+}