From 2896e67d87b08a1021101b869757be38e7bd3023 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Kali=C5=84ski?= <kacper.kalinski@miquido.com>
Date: Mon, 17 Jul 2023 14:41:54 +0200
Subject: [PATCH] Add retainContainer method

---
 FormatTool/Package.swift                      |  2 +-
 Sources/MQDo/Container/Features.swift         | 16 ++++++++++++++
 .../Container/Internal/FeaturesProxy.swift    | 22 +++++++++++++++++++
 .../Container/Internal/RootFeatures.swift     |  8 +++++++
 .../Container/Internal/ScopedFeatures.swift   |  8 +++++++
 Sources/MQDummy/Container/DummyFeatures.swift |  8 +++++++
 6 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/FormatTool/Package.swift b/FormatTool/Package.swift
index aad66a1..ea7ede3 100644
--- a/FormatTool/Package.swift
+++ b/FormatTool/Package.swift
@@ -7,7 +7,7 @@ let package = Package(
   dependencies: [
     .package(
       url: "https://github.com/apple/swift-format.git", 
-      exact: "508.0.0"
+      exact: "508.0.1"
     ),
   ],
   targets: [
diff --git a/Sources/MQDo/Container/Features.swift b/Sources/MQDo/Container/Features.swift
index 82598d1..7d7f6a4 100644
--- a/Sources/MQDo/Container/Features.swift
+++ b/Sources/MQDo/Container/Features.swift
@@ -1,5 +1,10 @@
 public protocol Features: Sendable {
 
+	@Sendable func retainContainer(
+		file: StaticString,
+		line: UInt
+	) throws -> FeaturesContainer
+
 	@Sendable func branch<Scope>(
 		_ scope: Scope.Type,
 		context: Scope.Context,
@@ -60,6 +65,17 @@ public protocol Features: Sendable {
 
 extension Features {
 
+	@_transparent
+	@Sendable func retainContainer(
+		file: StaticString = #file,
+		line: UInt = #line
+	) throws -> FeaturesContainer {
+		try self.retainContainer(
+			file: file,
+			line: line
+		)
+	}
+
 	@_transparent
 	@Sendable public func require<Scope>(
 		_ scope: Scope.Type,
diff --git a/Sources/MQDo/Container/Internal/FeaturesProxy.swift b/Sources/MQDo/Container/Internal/FeaturesProxy.swift
index b2c81bc..e4b5737 100644
--- a/Sources/MQDo/Container/Internal/FeaturesProxy.swift
+++ b/Sources/MQDo/Container/Internal/FeaturesProxy.swift
@@ -14,6 +14,28 @@ internal struct FeaturesProxy {
 
 extension FeaturesProxy: Features {
 
+	@Sendable internal func retainContainer(
+		file: StaticString,
+		line: UInt
+	) throws -> FeaturesContainer {
+		if let container: FeaturesContainer = self.container {
+			return container
+		}
+		else {
+			throw
+				FeaturesContainerUnavailable
+				.error(
+					file: file,
+					line: line
+				)
+				.asRuntimeWarning(
+					message: "Using detached features container. This is likely a memory issue.",
+					file: file,
+					line: line
+				)
+		}
+	}
+
 	@_transparent
 	@Sendable internal func require<Scope>(
 		_ scope: Scope.Type,
diff --git a/Sources/MQDo/Container/Internal/RootFeatures.swift b/Sources/MQDo/Container/Internal/RootFeatures.swift
index acc20fd..03a7cd0 100644
--- a/Sources/MQDo/Container/Internal/RootFeatures.swift
+++ b/Sources/MQDo/Container/Internal/RootFeatures.swift
@@ -21,6 +21,14 @@ extension RootFeatures: @unchecked Sendable {}
 
 extension RootFeatures: FeaturesContainer {
 
+	@_transparent
+	@Sendable internal func retainContainer(
+		file: StaticString,
+		line: UInt
+	) throws -> FeaturesContainer {
+		self
+	}
+
 	@_transparent
 	@Sendable internal func require<Scope>(
 		_ scope: Scope.Type,
diff --git a/Sources/MQDo/Container/Internal/ScopedFeatures.swift b/Sources/MQDo/Container/Internal/ScopedFeatures.swift
index 19aa5d7..c6c8390 100644
--- a/Sources/MQDo/Container/Internal/ScopedFeatures.swift
+++ b/Sources/MQDo/Container/Internal/ScopedFeatures.swift
@@ -28,6 +28,14 @@ extension ScopedFeatures: @unchecked Sendable {}
 
 extension ScopedFeatures: FeaturesContainer {
 
+	@_transparent
+	@Sendable internal func retainContainer(
+		file: StaticString,
+		line: UInt
+	) throws -> FeaturesContainer {
+		self
+	}
+
 	@Sendable internal func require<RequestedScope>(
 		_ scope: RequestedScope.Type,
 		file: StaticString,
diff --git a/Sources/MQDummy/Container/DummyFeatures.swift b/Sources/MQDummy/Container/DummyFeatures.swift
index 3992772..1701853 100644
--- a/Sources/MQDummy/Container/DummyFeatures.swift
+++ b/Sources/MQDummy/Container/DummyFeatures.swift
@@ -20,6 +20,14 @@ extension DummyFeatures: @unchecked Sendable {}
 
 extension DummyFeatures: FeaturesContainer {
 
+	@_transparent
+	@Sendable public func retainContainer(
+		file: StaticString,
+		line: UInt
+	) throws -> FeaturesContainer {
+		self
+	}
+
 	@Sendable public func context<Scope>(
 		for scope: Scope.Type,
 		file: StaticString,