fix: Plugins that are not configured correctly will be error at initial step (#642)

This change allows to call configure method of each plugin with a nil value. ie even if the corresponding configuration is not present in the configuration file, plugin's configure will be called. The plugin can decide to throw an error or handle the nil configuration.

Author: royjit

Amplify/Categories/API/Internal/APICategory+CategoryConfigurable.swift

@@ -7,7 +7,7 @@
 
 extension AmplifyAPICategory: CategoryConfigurable {
 
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         guard !isConfigured else {
             let error = ConfigurationError.amplifyAlreadyConfigured(
                 "\(categoryType.displayName) has already been configured.",
@@ -22,10 +22,7 @@ extension AmplifyAPICategory: CategoryConfigurable {
     }
 
     func configure(using amplifyConfiguration: AmplifyConfiguration) throws {
-        guard let configuration = categoryConfiguration(from: amplifyConfiguration) else {
-            return
-        }
-        try configure(using: configuration)
+        try configure(using: categoryConfiguration(from: amplifyConfiguration))
     }
 
 }

Amplify/Categories/Analytics/Internal/AnalyticsCategory+CategoryConfigurable.swift

@@ -7,7 +7,7 @@
 
 extension AnalyticsCategory: CategoryConfigurable {
 
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         guard !isConfigured else {
             let error = ConfigurationError.amplifyAlreadyConfigured(
                 "\(categoryType.displayName) has already been configured.",
@@ -22,10 +22,7 @@ extension AnalyticsCategory: CategoryConfigurable {
     }
 
     func configure(using amplifyConfiguration: AmplifyConfiguration) throws {
-        guard let configuration = categoryConfiguration(from: amplifyConfiguration) else {
-            return
-        }
-        try configure(using: configuration)
+        try configure(using: categoryConfiguration(from: amplifyConfiguration))
     }
 
 }

Amplify/Categories/Auth/Internal/AuthCategory+CategoryConfigurable.swift

@@ -9,7 +9,7 @@ import Foundation
 
 extension AuthCategory: CategoryConfigurable {
 
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         guard !isConfigured else {
             let error = ConfigurationError.amplifyAlreadyConfigured(
                 "\(categoryType.displayName) has already been configured.",
@@ -24,9 +24,6 @@ extension AuthCategory: CategoryConfigurable {
     }
 
     func configure(using amplifyConfiguration: AmplifyConfiguration) throws {
-        guard let configuration = categoryConfiguration(from: amplifyConfiguration) else {
-            return
-        }
-        try configure(using: configuration)
+        try configure(using: categoryConfiguration(from: amplifyConfiguration))
     }
 }

Amplify/Categories/DataStore/Internal/DataStoreCategory+Configurable.swift

@@ -15,7 +15,7 @@ extension DataStoreCategory: CategoryConfigurable {
         }
     }
 
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         guard !isConfigured else {
             let error = ConfigurationError.amplifyAlreadyConfigured(
                 "\(categoryType.displayName) has already been configured.",

Amplify/Categories/Hub/Internal/HubCategory+CategoryConfigurable.swift

@@ -9,7 +9,7 @@ extension HubCategory: CategoryConfigurable {
 
     /// Configures the HubCategory using the incoming CategoryConfiguration. If the incoming configuration does not
     /// specify a Hub plugin, then we will inject the AWSHubPlugin.
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         guard configurationState != .configured else {
             let error = ConfigurationError.amplifyAlreadyConfigured(
                 "\(categoryType.displayName) has already been configured.",
@@ -24,10 +24,7 @@ extension HubCategory: CategoryConfigurable {
     }
 
     func configure(using amplifyConfiguration: AmplifyConfiguration) throws {
-        guard let configuration = categoryConfiguration(from: amplifyConfiguration) else {
-            return
-        }
-        try configure(using: configuration)
+        try configure(using: categoryConfiguration(from: amplifyConfiguration))
     }
 
 }

Amplify/Categories/Logging/Internal/LoggingCategory+CategoryConfigurable.swift

@@ -8,7 +8,7 @@
 extension LoggingCategory: CategoryConfigurable {
 
     /// Configures the LoggingCategory using the incoming CategoryConfiguration.
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         try concurrencyQueue.sync {
             let plugin: LoggingCategoryPlugin
             switch configurationState {
@@ -26,17 +26,14 @@ extension LoggingCategory: CategoryConfigurable {
                 throw error
             }
 
-            try plugin.configure(using: configuration.plugins[plugin.key])
+            try plugin.configure(using: configuration?.plugins[plugin.key])
             self.plugin = plugin
             configurationState = .configured
         }
     }
 
     func configure(using amplifyConfiguration: AmplifyConfiguration) throws {
-        guard let configuration = categoryConfiguration(from: amplifyConfiguration) else {
-            return
-        }
-        try configure(using: configuration)
+        try configure(using: categoryConfiguration(from: amplifyConfiguration))
     }
 
 }

Amplify/Categories/Predictions/Internal/PredictionsCategory+CategoryConfigurable.swift

@@ -7,7 +7,7 @@
 
 extension PredictionsCategory: CategoryConfigurable {
 
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         guard !isConfigured else {
             let error = ConfigurationError.amplifyAlreadyConfigured(
                 "\(categoryType.displayName) has already been configured.",
@@ -22,10 +22,7 @@ extension PredictionsCategory: CategoryConfigurable {
     }
 
     func configure(using amplifyConfiguration: AmplifyConfiguration) throws {
-        guard let configuration = categoryConfiguration(from: amplifyConfiguration) else {
-            return
-        }
-        try configure(using: configuration)
+        try configure(using: categoryConfiguration(from: amplifyConfiguration))
     }
 
 }

Amplify/Categories/Storage/Internal/StorageCategory+CategoryConfigurable.swift

@@ -7,7 +7,7 @@
 
 extension StorageCategory: CategoryConfigurable {
 
-    func configure(using configuration: CategoryConfiguration) throws {
+    func configure(using configuration: CategoryConfiguration?) throws {
         guard !isConfigured else {
             let error = ConfigurationError.amplifyAlreadyConfigured(
                 "\(categoryType.displayName) has already been configured.",
@@ -22,10 +22,7 @@ extension StorageCategory: CategoryConfigurable {
     }
 
     func configure(using amplifyConfiguration: AmplifyConfiguration) throws {
-        guard let configuration = categoryConfiguration(from: amplifyConfiguration) else {
-            return
-        }
-        try configure(using: configuration)
+        try configure(using: categoryConfiguration(from: amplifyConfiguration))
     }
 
 }

Amplify/Core/Configuration/AmplifyConfiguration.swift

@@ -148,17 +148,19 @@ extension Amplify {
 
     /// Configures a list of plugins with the specified CategoryConfiguration. If any configurations do not match the
     /// specified plugins, emits a log warning.
-    static func configure(plugins: [Plugin], using configuration: CategoryConfiguration) throws {
-        var pluginConfigurations = configuration.plugins
+    static func configure(plugins: [Plugin], using configuration: CategoryConfiguration?) throws {
+        var pluginConfigurations = configuration?.plugins
 
         for plugin in plugins {
-            let pluginConfiguration = pluginConfigurations[plugin.key]
+            let pluginConfiguration = pluginConfigurations?[plugin.key]
             try plugin.configure(using: pluginConfiguration)
-            pluginConfigurations.removeValue(forKey: plugin.key)
+            pluginConfigurations?.removeValue(forKey: plugin.key)
         }
 
-        for unusedPluginKey in pluginConfigurations.keys {
-            log.warn("No plugin found for configuration key `\(unusedPluginKey)`. Add a plugin for that key.")
+        if let pluginKeys = pluginConfigurations?.keys {
+            for unusedPluginKey in pluginKeys {
+                log.warn("No plugin found for configuration key `\(unusedPluginKey)`. Add a plugin for that key.")
+            }
         }
     }
 

Amplify/Core/Configuration/Internal/CategoryConfigurable.swift

@@ -13,7 +13,7 @@ protocol CategoryConfigurable: class, CategoryTypeable {
     /// Configures the category and added plugins using `configuration`
     ///
     /// - Parameter configuration: The CategoryConfiguration
-    func configure(using configuration: CategoryConfiguration) throws
+    func configure(using configuration: CategoryConfiguration?) throws
 
     /// Convenience method for configuring the category using the top-level AmplifyConfiguration
     ///