From 6ec5b742efba03080a470cfc4ca5e77134cbd83c Mon Sep 17 00:00:00 2001
From: Dariusz Rybicki <dariusz@elixxir.io>
Date: Mon, 18 Jul 2022 13:01:04 +0100
Subject: [PATCH] Add CellFactory
---
Sources/CollectionView/CellFactory.swift | 64 ++++++++++++++++
.../CellFactoryTests.swift | 75 +++++++++++++++++++
2 files changed, 139 insertions(+)
create mode 100644 Sources/CollectionView/CellFactory.swift
create mode 100644 Tests/CollectionViewTests/CellFactoryTests.swift
diff --git a/Sources/CollectionView/CellFactory.swift b/Sources/CollectionView/CellFactory.swift
new file mode 100644
index 00000000..00faf2c2
--- /dev/null
+++ b/Sources/CollectionView/CellFactory.swift
@@ -0,0 +1,64 @@
+import UIKit
+
+public struct CellFactory<Model> {
+ public struct Registrar {
+ public var register: (UICollectionView) -> Void
+
+ public func callAsFunction(in view: UICollectionView) {
+ register(view)
+ }
+ }
+
+ public struct Builder {
+ public var buildCell: (Model, UICollectionView, IndexPath) -> UICollectionViewCell?
+
+ public func callAsFunction(
+ for model: Model,
+ in view: UICollectionView,
+ at indexPath: IndexPath
+ ) -> UICollectionViewCell? {
+ buildCell(model, view, indexPath)
+ }
+ }
+
+ public var register: Registrar
+ public var build: Builder
+
+ public init(
+ register: Registrar,
+ build: Builder
+ ) {
+ self.register = register
+ self.build = build
+ }
+}
+
+extension CellFactory {
+ public static func combined(_ factories: CellFactory...) -> CellFactory {
+ combined(factories)
+ }
+
+ public static func combined(_ factories: [CellFactory]) -> CellFactory {
+ CellFactory(
+ register: .init { collectionView in
+ factories.forEach { $0.register(in: collectionView) }
+ },
+ build: .init { model, collectionView, indexPath in
+ factories.lazy
+ .compactMap { $0.build(for: model, in: collectionView, at: indexPath) }
+ .first
+ }
+ )
+ }
+}
+
+#if DEBUG
+extension CellFactory {
+ public static func failing() -> CellFactory {
+ CellFactory(
+ register: .init { _ in fatalError("Not implemented") },
+ build: .init { _, _, _ in fatalError("Not implemented") }
+ )
+ }
+}
+#endif
diff --git a/Tests/CollectionViewTests/CellFactoryTests.swift b/Tests/CollectionViewTests/CellFactoryTests.swift
new file mode 100644
index 00000000..c9b052dd
--- /dev/null
+++ b/Tests/CollectionViewTests/CellFactoryTests.swift
@@ -0,0 +1,75 @@
+import XCTest
+@testable import CollectionView
+
+final class CellFactoryTests: XCTestCase {
+ func testCombined() {
+ var didRegisterFirst = [UICollectionView]()
+ var didRegisterSecond = [UICollectionView]()
+ var didRegisterThird = [UICollectionView]()
+
+ class Cell: UICollectionViewCell {
+ var collectionView: UICollectionView?
+ var indexPath: IndexPath?
+ }
+
+ let factory = CellFactory<Int>.combined(
+ .init(
+ register: .init { didRegisterFirst.append($0) },
+ build: .init { model, collectionView, indexPath in
+ guard model == 1 else { return nil }
+ let cell = Cell()
+ cell.collectionView = collectionView
+ cell.indexPath = indexPath
+ return cell
+ }
+ ),
+ .init(
+ register: .init { didRegisterSecond.append($0) },
+ build: .init { model, collectionView, indexPath in
+ guard model == 2 else { return nil }
+ let cell = Cell()
+ cell.collectionView = collectionView
+ cell.indexPath = indexPath
+ return cell
+ }
+ ),
+ .init(
+ register: .init { didRegisterThird.append($0) },
+ build: .init { model, collectionView, indexPath in
+ guard model == 3 else { return nil }
+ let cell = Cell()
+ cell.collectionView = collectionView
+ cell.indexPath = indexPath
+ return cell
+ }
+ )
+ )
+
+ let collectionView = UICollectionView(frame: .zero, collectionViewLayout: .init())
+
+ factory.register(in: collectionView)
+
+ XCTAssertEqual(didRegisterFirst, [collectionView])
+ XCTAssertEqual(didRegisterSecond, [collectionView])
+ XCTAssertEqual(didRegisterThird, [collectionView])
+
+ let firstCell = factory.build(for: 1, in: collectionView, at: IndexPath(item: 0, section: 1)) as? Cell
+
+ XCTAssertEqual(firstCell?.collectionView, collectionView)
+ XCTAssertEqual(firstCell?.indexPath, IndexPath(item: 0, section: 1))
+
+ let secondCell = factory.build(for: 2, in: collectionView, at: IndexPath(item: 2, section: 3)) as? Cell
+
+ XCTAssertEqual(secondCell?.collectionView, collectionView)
+ XCTAssertEqual(secondCell?.indexPath, IndexPath(item: 2, section: 3))
+
+ let thirdCell = factory.build(for: 3, in: collectionView, at: IndexPath(item: 4, section: 5)) as? Cell
+
+ XCTAssertEqual(thirdCell?.collectionView, collectionView)
+ XCTAssertEqual(thirdCell?.indexPath, IndexPath(item: 4, section: 5))
+
+ let otherCell = factory.build(for: 4, in: collectionView, at: IndexPath(item: 0, section: 0))
+
+ XCTAssertNil(otherCell)
+ }
+}
--
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