Refactor variable expansion

This change eliminates a swiftlint cyclomatic_complexity issue
SwiftScream · Jun 10, 2024 · c40686d · c40686d
1 parent c63916d
commit c40686d
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Showing 2 changed files with 32 additions and 27 deletions.
diff --git a/Sources/ScreamURITemplate/Internal/Components.swift b/Sources/ScreamURITemplate/Internal/Components.swift
@@ -64,36 +64,14 @@ struct ExpressionComponent: Component {
         self.templatePosition = templatePosition
     }
 
-    // swiftlint:disable:next cyclomatic_complexity
     func expand(variables: VariableProvider) throws -> String {
         let configuration = expressionOperator.expansionConfiguration()
         let expansions = try variableList.compactMap { variableSpec -> String? in
             guard let value = variables[String(variableSpec.name)]?.asTypedVariableValue() else {
                 return nil
             }
             do {
-                switch value {
-                case let .string(plainValue):
-                    return try plainValue.formatForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
-                case let .list(arrayValue):
-                    switch variableSpec.modifier {
-                    case .prefix:
-                        throw FormatError.failure(reason: "Prefix operator can only be applied to string")
-                    case .explode:
-                        return try arrayValue.explodeForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
-                    case .none:
-                        return try arrayValue.formatForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
-                    }
-                case let .associativeArray(associativeArrayValue):
-                    switch variableSpec.modifier {
-                    case .prefix:
-                        throw FormatError.failure(reason: "Prefix operator can only be applied to string")
-                    case .explode:
-                        return try associativeArrayValue.explodeForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
-                    case .none:
-                        return try associativeArrayValue.formatForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
-                    }
-                }
+                return try value.formatForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
             } catch let FormatError.failure(reason) {
                 throw URITemplate.Error.expansionFailure(position: templatePosition, reason: "Failed expanding variable \"\(variableSpec.name)\": \(reason)")
             }

diff --git a/Sources/ScreamURITemplate/Internal/ValueFormatting.swift b/Sources/ScreamURITemplate/Internal/ValueFormatting.swift
@@ -18,7 +18,34 @@ enum FormatError: Error {
     case failure(reason: String)
 }
 
-func percentEncode(string: String, withAllowedCharacters allowedCharacterSet: CharacterSet, allowPercentEncodedTriplets: Bool) throws -> String {
+extension TypedVariableValue {
+    func formatForTemplateExpansion(variableSpec: VariableSpec, expansionConfiguration configuration: ExpansionConfiguration) throws -> String? {
+        switch self {
+        case let .string(plainValue):
+            return try plainValue.formatForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
+        case let .list(arrayValue):
+            switch variableSpec.modifier {
+            case .prefix:
+                throw FormatError.failure(reason: "Prefix operator can only be applied to string")
+            case .explode:
+                return try arrayValue.explodeForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
+            case .none:
+                return try arrayValue.formatForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
+            }
+        case let .associativeArray(associativeArrayValue):
+            switch variableSpec.modifier {
+            case .prefix:
+                throw FormatError.failure(reason: "Prefix operator can only be applied to string")
+            case .explode:
+                return try associativeArrayValue.explodeForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
+            case .none:
+                return try associativeArrayValue.formatForTemplateExpansion(variableSpec: variableSpec, expansionConfiguration: configuration)
+            }
+        }
+    }
+}
+
+private func percentEncode(string: String, withAllowedCharacters allowedCharacterSet: CharacterSet, allowPercentEncodedTriplets: Bool) throws -> String {
     guard var encoded = string.addingPercentEncoding(withAllowedCharacters: allowedCharacterSet) else {
         throw FormatError.failure(reason: "Percent Encoding Failed")
     }
@@ -45,7 +72,7 @@ func percentEncode(string: String, withAllowedCharacters allowedCharacterSet: Ch
     return encoded
 }
 
-extension StringProtocol {
+private extension StringProtocol {
     func formatForTemplateExpansion(variableSpec: VariableSpec, expansionConfiguration: ExpansionConfiguration) throws -> String {
         let modifiedValue = if let prefixLength = variableSpec.prefixLength() {
             String(prefix(prefixLength))
@@ -63,7 +90,7 @@ extension StringProtocol {
     }
 }
 
-extension Array where Element: StringProtocol {
+private extension Array where Element: StringProtocol {
     func formatForTemplateExpansion(variableSpec: VariableSpec, expansionConfiguration: ExpansionConfiguration) throws -> String? {
         let separator = ","
         let encodedExpansions = try map { element -> String in
@@ -101,7 +128,7 @@ extension Array where Element: StringProtocol {
     }
 }
 
-extension [TypedVariableValue.AssociativeArrayElement] {
+private extension [TypedVariableValue.AssociativeArrayElement] {
     func formatForTemplateExpansion(variableSpec: VariableSpec, expansionConfiguration: ExpansionConfiguration) throws -> String? {
         let encodedExpansions = try map { key, value -> String in
             let encodedKey = try percentEncode(string: String(key), withAllowedCharacters: expansionConfiguration.percentEncodingAllowedCharacterSet, allowPercentEncodedTriplets: expansionConfiguration.allowPercentEncodedTriplets)