fix(Core): Fix plugin configuration validation (#543)

Previous validation logic threw an error if it encountered a configuration
stanza with no corresponding plugin registered for that key. However, the
current CLI emits some plugin keys in unexpected situations, breaking this
validation. Remediation would require a customer to edit the config file, which
is possibly dangerous, and definitely inconvenient.

This change:
- Replaces the throwing error with a logged warning when the config encounters
  an unmatched plugin key
- Changes the `Plugin.configure` signature to accept an optional `Any?`
  argument, instead of a non-optional. This will let plugins decide if they
  need to throw or not.
- Fixes a data race in hub test code
- Fix AWSCognitoAuthPlugin and AWSS3StoragePlugin to throw a PluginError
  instead of a category-specific error if they encounter an error during
  configuration

fixes #540

Author: palpatim

Amplify.xcodeproj/project.pbxproj

@@ -2834,9 +2834,9 @@
 		FAC2354C227A056600424678 /* CategoryTests */ = {
 			isa = PBXGroup;
 			children = (
-				B4F3E9F624314E1300F23296 /* Auth */,
 				FAC2355D227A056600424678 /* Analytics */,
 				FAC23555227A056600424678 /* API */,
+				B4F3E9F624314E1300F23296 /* Auth */,
 				FAD3937B23820CE200463F5E /* DataStore */,
 				FAC23584227A442000424678 /* Hub */,
 				FAC23559227A056600424678 /* Logging */,
@@ -2956,9 +2956,9 @@
 			isa = PBXGroup;
 			children = (
 				FA607FE1233D131B00DFEA24 /* AmplifyOperationHubTests.swift */,
-				FACF52052329652600646E10 /* DefaultPluginTests */,
 				FAC23585227A443200424678 /* HubCategoryConfigurationTests.swift */,
 				FAC23587227A446C00424678 /* HubClientAPITests.swift */,
+				FACF52052329652600646E10 /* DefaultPluginTests */,
 			);
 			path = Hub;
 			sourceTree = "<group>";

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

@@ -16,10 +16,7 @@ extension AmplifyAPICategory: CategoryConfigurable {
             throw error
         }
 
-        for (pluginKey, pluginConfiguration) in configuration.plugins {
-            let plugin = try getPlugin(for: pluginKey)
-            try plugin.configure(using: pluginConfiguration)
-        }
+        try Amplify.configure(plugins: Array(plugins.values), using: configuration)
 
         isConfigured = true
     }

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

@@ -16,10 +16,7 @@ extension AnalyticsCategory: CategoryConfigurable {
             throw error
         }
 
-        for (pluginKey, pluginConfiguration) in configuration.plugins {
-            let plugin = try getPlugin(for: pluginKey)
-            try plugin.configure(using: pluginConfiguration)
-        }
+        try Amplify.configure(plugins: Array(plugins.values), using: configuration)
 
         isConfigured = true
     }

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

@@ -18,10 +18,7 @@ extension AuthCategory: CategoryConfigurable {
             throw error
         }
 
-        for (pluginKey, pluginConfiguration) in configuration.plugins {
-            let plugin = try getPlugin(for: pluginKey)
-            try plugin.configure(using: pluginConfiguration)
-        }
+        try Amplify.configure(plugins: Array(plugins.values), using: configuration)
 
         isConfigured = true
     }

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

@@ -24,10 +24,7 @@ extension DataStoreCategory: CategoryConfigurable {
             throw error
         }
 
-        for (pluginKey, pluginConfiguration) in configuration.plugins {
-            let plugin = try getPlugin(for: pluginKey)
-            try plugin.configure(using: pluginConfiguration)
-        }
+        try Amplify.configure(plugins: Array(plugins.values), using: configuration)
 
         isConfigured = true
     }

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

@@ -18,10 +18,7 @@ extension HubCategory: CategoryConfigurable {
             throw error
         }
 
-        for (pluginKey, pluginConfiguration) in configuration.plugins {
-            let plugin = try getPlugin(for: pluginKey)
-            try plugin.configure(using: pluginConfiguration)
-        }
+        try Amplify.configure(plugins: Array(plugins.values), using: configuration)
 
         configurationState = .configured
     }

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

@@ -26,18 +26,7 @@ extension LoggingCategory: CategoryConfigurable {
                 throw error
             }
 
-            guard let pluginConfiguration = configuration.plugins[plugin.key] else {
-                throw LoggingError.configuration(
-                    "No configuration found for added plugin `\(plugin.key)`",
-                    """
-                    Either fix the configuration file to specify the plugin's key value of '\(plugin.key)',
-                    or add a plugin with one of the keys specified in the configuration:
-                    \(configuration.plugins.keys.joined(separator: ", "))
-                    """
-                )
-            }
-
-            try plugin.configure(using: pluginConfiguration)
+            try plugin.configure(using: configuration.plugins[plugin.key])
             self.plugin = plugin
             configurationState = .configured
         }

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

@@ -16,10 +16,7 @@ extension PredictionsCategory: CategoryConfigurable {
             throw error
         }
 
-        for (pluginKey, pluginConfiguration) in configuration.plugins {
-            let plugin = try getPlugin(for: pluginKey)
-            try plugin.configure(using: pluginConfiguration)
-        }
+        try Amplify.configure(plugins: Array(plugins.values), using: configuration)
 
         isConfigured = true
     }

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

@@ -16,10 +16,7 @@ extension StorageCategory: CategoryConfigurable {
             throw error
         }
 
-        for (pluginKey, pluginConfiguration) in configuration.plugins {
-            let plugin = try getPlugin(for: pluginKey)
-            try plugin.configure(using: pluginConfiguration)
-        }
+        try Amplify.configure(plugins: Array(plugins.values), using: configuration)
 
         isConfigured = true
     }

Amplify/Core/Configuration/AmplifyConfiguration.swift

@@ -145,4 +145,21 @@ extension Amplify {
 
         try configurable.configure(using: configuration)
     }
+
+    /// 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
+
+        for plugin in plugins {
+            let pluginConfiguration = pluginConfigurations[plugin.key]
+            try plugin.configure(using: pluginConfiguration)
+            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.")
+        }
+    }
+
 }