Built-in Assembly traversal

Swinject · Jan 23, 2021 · 95f085e · 95f085e
1 parent d204ced
commit 95f085e
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Showing 5 changed files with 104 additions and 5 deletions.
diff --git a/Sources/Assembler.swift b/Sources/Assembler.swift
@@ -113,12 +113,25 @@ public final class Assembler {
     private func run(assemblies: [Assembly]) {
         // build the container from each assembly
         for assembly in assemblies {
-            assembly.assemble(container: container)
+            assemble(assembly)
         }
-
         // inform all of the assemblies that the container is loaded
         for assembly in assemblies {
-            assembly.loaded(resolver: resolver)
+            loaded(assembly)
+        }
+    }
+
+    private func assemble(_ assembly: Assembly) {
+        for child in assembly.children {
+            assemble(child)
+        }
+        assembly.assemble(container: container)
+    }
+
+    private func loaded(_ assembly: Assembly) {
+        for child in assembly.children {
+            loaded(child)
         }
+        assembly.loaded(resolver: resolver)
     }
 }
diff --git a/Sources/Assembly.swift b/Sources/Assembly.swift
@@ -18,10 +18,22 @@ public protocol Assembly {
     /// - parameter resolver: the resolver that can resolve instances from the built container
     ///
     func loaded(resolver: Resolver)
+
+    /// Provides a hook to allow `Assembler` to traverse down an Assembly tree. Child `Assembly` instances
+    /// are automatically assembled and any `loaded(...)` hooks are called in depth-first order
+    ///
+    /// - parameter container: the container provided by the `Assembler`
+    ///
+    var children: [Assembly] { get }
 }
 
 public extension Assembly {
     func loaded(resolver _: Resolver) {
         // no-op
     }
+
+    var children: [Assembly] {
+        // no-op (empty children)
+        []
+    }
 }
diff --git a/Swinject.xcodeproj/project.pbxproj b/Swinject.xcodeproj/project.pbxproj
@@ -227,6 +227,10 @@
 		FED7D8B8C74876D03B5D09DE /* Assembler.swift in Sources */ = {isa = PBXBuildFile; fileRef = 944B981A9157833AC3397B4A /* Assembler.swift */; };
 		FF222640214C9F4DA56130C4 /* InstanceStorage.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3B7688D6F1E3466891D0582E /* InstanceStorage.swift */; };
 		FF9DCB0AB20B0DBBE79451BB /* BehaviorFakes.swift in Sources */ = {isa = PBXBuildFile; fileRef = BEF07245CC462D98868097A3 /* BehaviorFakes.swift */; };
+		FFEB22D425BC935500EC89A1 /* NestedAssemblers.swift in Sources */ = {isa = PBXBuildFile; fileRef = FFEB22D325BC935500EC89A1 /* NestedAssemblers.swift */; };
+		FFEB22D525BC935500EC89A1 /* NestedAssemblers.swift in Sources */ = {isa = PBXBuildFile; fileRef = FFEB22D325BC935500EC89A1 /* NestedAssemblers.swift */; };
+		FFEB22D625BC935500EC89A1 /* NestedAssemblers.swift in Sources */ = {isa = PBXBuildFile; fileRef = FFEB22D325BC935500EC89A1 /* NestedAssemblers.swift */; };
+		FFEB22D725BC935500EC89A1 /* NestedAssemblers.swift in Sources */ = {isa = PBXBuildFile; fileRef = FFEB22D325BC935500EC89A1 /* NestedAssemblers.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -383,6 +387,7 @@
 		F388AD8E55D8C6F1E31D0522 /* FunctionType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FunctionType.swift; sourceTree = "<group>"; };
 		FCC59458E04C20587D870946 /* BasicAssembly.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BasicAssembly.swift; sourceTree = "<group>"; };
 		FFBC1F44A2B361CB169F7B66 /* Animal.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Animal.swift; sourceTree = "<group>"; };
+		FFEB22D325BC935500EC89A1 /* NestedAssemblers.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NestedAssemblers.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -436,6 +441,7 @@
 				FFBC1F44A2B361CB169F7B66 /* Animal.swift */,
 				1525F92CDAA706A848343E2B /* AssemblerSpec.swift */,
 				FCC59458E04C20587D870946 /* BasicAssembly.swift */,
+				FFEB22D325BC935500EC89A1 /* NestedAssemblers.swift */,
 				BEF07245CC462D98868097A3 /* BehaviorFakes.swift */,
 				47328731EED63322AD76FB3A /* Circularity.swift */,
 				2C662DAE2FD2FCCA8585DB89 /* ContainerSpec.Arguments.swift */,
@@ -768,8 +774,6 @@
 			isa = PBXProject;
 			attributes = {
 				LastUpgradeCheck = 1200;
-				TargetAttributes = {
-				};
 			};
 			buildConfigurationList = 0102B3F56FB5455C665EC043 /* Build configuration list for PBXProject "Swinject" */;
 			compatibilityVersion = "Xcode 10.0";
@@ -953,6 +957,7 @@
 				229E0EAD0D8413D4CA67094C /* ContainerSpec.DebugHelper.swift in Sources */,
 				B3A1A6E559CC128BF501EC1D /* ContainerSpec.GraphCaching.swift in Sources */,
 				2A207632400E46F722193C7E /* ContainerSpec.TypeForwarding.swift in Sources */,
+				FFEB22D425BC935500EC89A1 /* NestedAssemblers.swift in Sources */,
 				A9E5D5915FE433CD1DCD0022 /* ContainerSpec.swift in Sources */,
 				1276420B3D3ED5ACFC2C5B4F /* EmploymentAssembly.swift in Sources */,
 				0266A3114C82246F18B52860 /* Food.swift in Sources */,
@@ -984,6 +989,7 @@
 				499ADF9E7F4ADEEB5465FFB6 /* ContainerSpec.DebugHelper.swift in Sources */,
 				50FC209AE23CD1E502149C5C /* ContainerSpec.GraphCaching.swift in Sources */,
 				2AED444F7141B101091A1464 /* ContainerSpec.TypeForwarding.swift in Sources */,
+				FFEB22D525BC935500EC89A1 /* NestedAssemblers.swift in Sources */,
 				07C2E78624A40118D0316CB6 /* ContainerSpec.swift in Sources */,
 				75A776D4072BCF74F298D818 /* EmploymentAssembly.swift in Sources */,
 				44676A0D0399F323A31E0451 /* Food.swift in Sources */,
@@ -1015,6 +1021,7 @@
 				82A930EA09492BAFE7D4D2DF /* ContainerSpec.DebugHelper.swift in Sources */,
 				FD72CBB5F6A75CE6C785058E /* ContainerSpec.GraphCaching.swift in Sources */,
 				BB35F3F717A09AD398FCC67A /* ContainerSpec.TypeForwarding.swift in Sources */,
+				FFEB22D725BC935500EC89A1 /* NestedAssemblers.swift in Sources */,
 				1BD861CA392B1E63D249906B /* ContainerSpec.swift in Sources */,
 				3A41F4B375C1CE29A75F6AE9 /* EmploymentAssembly.swift in Sources */,
 				115515373F266C35E8DBE724 /* Food.swift in Sources */,
@@ -1046,6 +1053,7 @@
 				4CC5158454FA6586C84AB160 /* ContainerSpec.DebugHelper.swift in Sources */,
 				2DF02DA2EB1C70640DCC315D /* ContainerSpec.GraphCaching.swift in Sources */,
 				4077A7732A2412CBB9E8A759 /* ContainerSpec.TypeForwarding.swift in Sources */,
+				FFEB22D625BC935500EC89A1 /* NestedAssemblers.swift in Sources */,
 				41084A2F24BB4222CCFFAD27 /* ContainerSpec.swift in Sources */,
 				1613AE7671758A85F760C5DF /* EmploymentAssembly.swift in Sources */,
 				4736BF9B29704061B29BFACD /* Food.swift in Sources */,

diff --git a/Tests/SwinjectTests/AssemblerSpec.swift b/Tests/SwinjectTests/AssemblerSpec.swift
@@ -325,5 +325,34 @@ class AssemblerSpec: QuickSpec {
                 expect(spy.entries).to(haveCount(1))
             }
         }
+
+        describe("Nested Assemblers") {
+            it("assembles and calls loaded depth-first") {
+                let container = Container()
+
+                let assemble = NestedAssembly.ArrayType()
+                let loaded = NestedAssembly.ArrayType()
+
+                container.register(
+                    NestedAssembly.ArrayType.self,
+                    name: NestedAssembly.Constants.assemble
+                ) { _ in assemble }
+                    .inObjectScope(.container)
+                container.register(
+                    NestedAssembly.ArrayType.self,
+                    name: NestedAssembly.Constants.loaded
+                ) { _ in loaded }
+                    .inObjectScope(.container)
+
+                let d = NestedAssembly(name: "d", children: [])
+                let c = NestedAssembly(name: "c", children: [d])
+                let b = NestedAssembly(name: "b", children: [])
+                let a = NestedAssembly(name: "a", children: [b, c])
+
+                _ = Assembler([a], container: container)
+                expect(assemble).to(equal(["b", "d", "c", "a"]))
+                expect(loaded).to(equal(["b", "d", "c", "a"]))
+            }
+        }
     }
 }
diff --git a/Tests/SwinjectTests/NestedAssemblers.swift b/Tests/SwinjectTests/NestedAssemblers.swift
@@ -0,0 +1,37 @@
+//
+//  Copyright © 2021 Swinject Contributors. All rights reserved.
+//
+
+import Swinject
+import Foundation
+
+struct NestedAssembly: Assembly {
+
+    typealias ArrayType = NSMutableArray
+
+    enum Constants {
+        static let assemble = "assemble"
+        static let loaded = "loaded"
+    }
+
+    struct Logger {
+        let name: String
+        let array = ArrayType()
+    }
+
+    let name: String
+    let children: [Assembly]
+
+    init(name: String, children: [Assembly]) {
+        self.name = name
+        self.children = children
+    }
+
+    func assemble(container: Container) {
+        container.resolve(ArrayType.self, name: Constants.assemble)?.add(name)
+    }
+
+    func loaded(resolver: Resolver) {
+        resolver.resolve(ArrayType.self, name: Constants.loaded)?.add(name)
+    }
+}