add swiftUI code

iOS-SwiftUI-Code/GRDB.swift-6.29.3/Tests/GRDBTests/SingletonUserDefaultsTest.swift

@@ -0,0 +1,174 @@
+import XCTest
+import GRDB
+
+private struct AppConfiguration: Codable {
+    // Support for the single row guarantee
+    private var id = 1
+    
+    // The stored properties
+    private var storedText: String?
+    // ... other properties
+    
+    // The public properties
+    var text: String {
+        get { storedText ?? "default" }
+        set { storedText = newValue }
+    }
+    
+    mutating func resetText() {
+        storedText = nil
+    }
+}
+
+extension AppConfiguration {
+    /// The default configuration
+    static let `default` = AppConfiguration()
+}
+
+// Database Access
+extension AppConfiguration: FetchableRecord, PersistableRecord {
+    // Customize the default PersistableRecord behavior
+    func willUpdate(_ db: Database, columns: Set<String>) throws {
+        // Insert the default configuration if it does not exist yet.
+        if try !exists(db) {
+            try AppConfiguration.default.insert(db)
+        }
+    }
+    
+    /// Returns the persisted configuration, or the default one if the
+    /// database table is empty.
+    static func find(_ db: Database) throws -> AppConfiguration {
+        try fetchOne(db) ?? .default
+    }
+}
+
+class SingletonUserDefaultsTest: GRDBTestCase {
+    private func createEmptyAppConfigurationTable(_ db: Database) throws {
+        // Table creation
+        try db.create(table: "appConfiguration") { t in
+            // Single row guarantee
+            t.primaryKey("id", .integer, onConflict: .replace).check { $0 == 1 }
+            
+            // The configuration columns
+            t.column("storedText", .text)
+            // ... other columns
+        }
+    }
+    
+    func test_find_in_empty_database() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            // When
+            let config = try AppConfiguration.find(db)
+            // Then
+            XCTAssertEqual(config.text, "default")
+        }
+    }
+    
+    func test_find_in_populated_database_null() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            try AppConfiguration().insert(db)
+            // When
+            let config = try AppConfiguration.find(db)
+            // Then
+            XCTAssertEqual(config.text, "default")
+        }
+    }
+    
+    func test_find_from_populated_database_not_null() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            try db.execute(sql: "INSERT INTO appConfiguration(storedText) VALUES ('initial')")
+            // When
+            let config = try AppConfiguration.find(db)
+            // Then
+            XCTAssertEqual(config.text, "initial")
+        }
+    }
+    
+    func test_save_in_empty_database() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            // When
+            var appConfiguration = try AppConfiguration.find(db)
+            appConfiguration.text = "test"
+            try appConfiguration.save(db)
+            // Then
+            try XCTAssertEqual(AppConfiguration.find(db).text, "test")
+            let row = try XCTUnwrap(Row.fetchOne(db, sql: "SELECT * FROM appConfiguration"))
+            XCTAssertEqual(row, ["id": 1, "storedText": "test"])
+        }
+    }
+    
+    func test_save_in_populated_database() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            try db.execute(sql: "INSERT INTO appConfiguration(storedText) VALUES ('initial')")
+            // When
+            var appConfiguration = try AppConfiguration.find(db)
+            appConfiguration.text = "test"
+            try appConfiguration.save(db)
+            // Then
+            try XCTAssertEqual(AppConfiguration.find(db).text, "test")
+            let row = try XCTUnwrap(Row.fetchOne(db, sql: "SELECT * FROM appConfiguration"))
+            XCTAssertEqual(row, ["id": 1, "storedText": "test"])
+        }
+    }
+    
+    func test_reset_and_save_in_populated_database() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            try db.execute(sql: "INSERT INTO appConfiguration(storedText) VALUES ('initial')")
+            // When
+            var appConfiguration = try AppConfiguration.find(db)
+            appConfiguration.resetText()
+            try appConfiguration.save(db)
+            // Then
+            try XCTAssertEqual(AppConfiguration.find(db).text, "default")
+            let row = try XCTUnwrap(Row.fetchOne(db, sql: "SELECT * FROM appConfiguration"))
+            XCTAssertEqual(row, ["id": 1, "storedText": nil])
+        }
+    }
+    
+    func test_update_changes_in_empty_database() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            // When
+            var config = try AppConfiguration.find(db)
+            try config.updateChanges(db) {
+                $0.text = "test"
+            }
+            // Then
+            XCTAssertEqual(config.text, "test")
+            try XCTAssertEqual(AppConfiguration.find(db).text, "test")
+            let row = try XCTUnwrap(Row.fetchOne(db, sql: "SELECT * FROM appConfiguration"))
+            XCTAssertEqual(row, ["id": 1, "storedText": "test"])
+        }
+    }
+    
+    func test_update_changes_in_populated_database() throws {
+        try makeDatabaseQueue().write { db in
+            // Given
+            try createEmptyAppConfigurationTable(db)
+            try db.execute(sql: "INSERT INTO appConfiguration(storedText) VALUES ('initial')")
+            // When
+            var config = try AppConfiguration.find(db)
+            try config.updateChanges(db) {
+                $0.text = "test"
+            }
+            // Then
+            XCTAssertEqual(config.text, "test")
+            try XCTAssertEqual(AppConfiguration.find(db).text, "test")
+            let row = try XCTUnwrap(Row.fetchOne(db, sql: "SELECT * FROM appConfiguration"))
+            XCTAssertEqual(row, ["id": 1, "storedText": "test"])
+        }
+    }
+}