Feat: Adding a pure Swift Configuration File Reader

AWSSDKSwiftCLI/Sources/AWSSDKSwiftCLI/Resources/Package.Base.txt

@@ -213,6 +213,13 @@ private var runtimeTargets: [Target] {
             name: "AWSSDKDynamic",
             path: "Sources/Core/AWSSDKDynamic/Sources/AWSSDKDynamic"
         ),
+        .target(
+            name: "AWSSDKConfigFileReader",
+            dependencies: [
+                .AWSSDKCommon,
+            ],
+            path: "Sources/Core/AWSSDKConfigFileReader/Sources/AWSSDKConfigFileReader"
+        ),
     ] + internalServiceTargets
 }
 
@@ -271,6 +278,15 @@ private var runtimeTestTargets: [Target] {
             path: "Sources/Core/AWSSDKIdentity/Tests/AWSSDKIdentityTests",
             resources: [.process("Resources")]
         ),
+        .testTarget(
+            name: "AWSSDKConfigFileReaderTests",
+            dependencies: [
+                .AWSSDKCommon,
+                "AWSSDKConfigFileReader",
+            ],
+            path: "Sources/Core/AWSSDKConfigFileReader/Tests/AWSSDKConfigFileReaderTests",
+            resources: [.process("Resources")]
+        ),
     ]
 }
 

Package.swift

@@ -2365,6 +2365,13 @@ private var runtimeTargets: [Target] {
             name: "AWSSDKDynamic",
             path: "Sources/Core/AWSSDKDynamic/Sources/AWSSDKDynamic"
         ),
+        .target(
+            name: "AWSSDKConfigFileReader",
+            dependencies: [
+                .AWSSDKCommon,
+            ],
+            path: "Sources/Core/AWSSDKConfigFileReader/Sources/AWSSDKConfigFileReader"
+        ),
     ] + internalServiceTargets
 }
 
@@ -2423,6 +2430,15 @@ private var runtimeTestTargets: [Target] {
             path: "Sources/Core/AWSSDKIdentity/Tests/AWSSDKIdentityTests",
             resources: [.process("Resources")]
         ),
+        .testTarget(
+            name: "AWSSDKConfigFileReaderTests",
+            dependencies: [
+                .AWSSDKCommon,
+                "AWSSDKConfigFileReader",
+            ],
+            path: "Sources/Core/AWSSDKConfigFileReader/Tests/AWSSDKConfigFileReaderTests",
+            resources: [.process("Resources")]
+        ),
     ]
 }
 

Sources/Core/AWSSDKConfigFileReader/Sources/AWSSDKConfigFileReader/ConfigFileModels.swift

@@ -0,0 +1,82 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+@_spi(FileBasedConfig) import AWSSDKCommon
+import Foundation
+
+struct ConfigFile: FileBasedConfiguration {
+    let sections: [String: ConfigFileSection]
+
+    func section(for name: String, type: FileBasedConfigurationSectionType) -> (any FileBasedConfigurationSection)? {
+        let typePrefix: String
+        switch type {
+        case .profile:
+            typePrefix = "profile"
+        case .ssoSession:
+            typePrefix = "sso-session"
+        case .services:
+            typePrefix = "services"
+        }
+
+        let fullKey: String
+        if name == "default" {
+            if let explicit = sections["profile default"] { return explicit }
+            fullKey = "default"
+        } else {
+            fullKey = "\(typePrefix) \(name)"
+        }
+
+        // First try the exact type match
+        if let section = sections[fullKey] {
+            return section
+        }
+
+        // If no exact match and we're looking for a profile, try other section types
+        // This allows the default section(for: name) method to find any section type
+        if type == .profile {
+            // Try sso-session
+            if let ssoSection = sections["sso-session \(name)"] {
+                return ssoSection
+            }
+            // Try services
+            if let servicesSection = sections["services \(name)"] {
+                return servicesSection
+            }
+        }
+
+        return nil
+    }
+}
+
+struct ConfigFileSection: FileBasedConfigurationSection {
+    let name: String
+    var subproperties: [String: [String: String]] = [:]
+    var properties: [String: String] = [:]
+
+    func property(for name: FileBasedConfigurationKey) -> FileBasedConfigurationProperty? {
+        if let value = properties[name.rawValue]{
+            return .string(value)
+        } else if let subproperties = subproperties[name.rawValue] {
+            return .subsection(Subsection(subproperties: subproperties))
+        }
+        return nil
+    }
+}
+
+struct Config: FileBasedConfigurationSectionProviding {
+    func section(for name: String, type: AWSSDKCommon.FileBasedConfigurationSectionType) -> (any AWSSDKCommon.FileBasedConfigurationSection)? {
+        return nil
+    }
+}
+
+struct Subsection: FileBasedConfigurationSubsection {
+    var subproperties: [String: String]
+
+    func value(for name: AWSSDKCommon.FileBasedConfigurationKey) -> String? {
+        subproperties[name.rawValue]
+    }
+}

Sources/Core/AWSSDKConfigFileReader/Sources/AWSSDKConfigFileReader/ConfigFileParser.swift

@@ -0,0 +1,112 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+
+class ConfigFileParser {
+    private var sections: [String: [String: String]] = [:]
+    private var currentSection: String?
+    private var currentProperty: String?
+
+    func parse(_ content: String) throws -> [String: [String: String]] {
+        for line in content.split(whereSeparator: \.isNewline) {
+            let lineString = String(line)
+            switch lineString.classification {
+            case .blank, .comment:    continue
+            case .section(let raw, _): try readSectionLine(raw)
+            case .property(let raw, _, _): try readPropertyLine(raw)
+            case .multiLine(let raw, _): try readContinuationLine(raw)
+            case .unknown:
+                guard currentSection != nil else { throw ParserError.noSectionDefined }
+                    throw ParserError.missingEqualsSign
+            }
+        }
+        return sections
+    }
+
+    enum ParserError: Error, LocalizedError {
+        case noSectionDefined
+        case noPropertyDefined
+        case emptyPropertyKey
+        case missingEqualsSign
+        case missingEqualsSignInSubProperty
+        case sectionMissingClosingBracket
+        case emptySubPropertyKey
+
+        var errorDescription: String? {
+            switch self {
+            case .noSectionDefined: return "Expected a section definition"
+            case .noPropertyDefined: return "Expected a property definition, found continuation"
+            case .emptyPropertyKey: return "Property did not have a name"
+            case .missingEqualsSign: return "Expected an '=' sign defining a property"
+            case .missingEqualsSignInSubProperty: return "Expected an '=' sign defining a property in sub-property"
+            case .sectionMissingClosingBracket: return "Section definition must end with ']'"
+            case .emptySubPropertyKey: return "Property did not have a name in sub-property"
+            }
+        }
+    }
+
+
+    private func readSectionLine(_ line: String) throws {
+        // Strip trailing comments (section headers allow # or ; without space)
+        var clean = line
+        if let range = clean.range(of: #"\s*[#;].*$"#, options: .regularExpression) {
+            clean = String(clean[..<range.lowerBound])
+        }
+        clean = clean.trimmingCharacters(in: .whitespaces)
+        guard clean.hasSuffix("]") else {throw ParserError.sectionMissingClosingBracket}
+        // Remove brackets
+        let inner = String(clean.dropFirst().dropLast()).trimmingCharacters(in: .whitespaces)
+        currentSection = inner
+        currentProperty = nil
+        if sections[inner] == nil { sections[inner] = [:] }
+    }
+
+    private func readPropertyLine(_ line: String) throws {
+        guard let section = currentSection else { throw ParserError.noSectionDefined }
+        // Property comments require whitespace before # or ;
+        var clean = line
+        for pattern in [" #", " ;", "\t#", "\t;"] {
+            if let idx = clean.range(of: pattern) {
+                clean = String(clean[..<idx.lowerBound])
+            }
+        }
+        clean = clean.trimmingCharacters(in: .whitespaces)
+        guard let eqIdx = clean.firstIndex(of: "=") else { throw ParserError.missingEqualsSign }
+        let key = String(clean[..<eqIdx]).trimmingCharacters(in: .whitespaces).lowercased()
+        guard !key.isEmpty else { throw ParserError.emptyPropertyKey }
+
+        let value = String(clean[clean.index(after: eqIdx)...]).trimmingCharacters(in: .whitespaces)
+        currentProperty = key
+        sections[section]?[key] = value
+    }
+
+    private func readContinuationLine(_ line: String) throws {
+        guard currentSection != nil else {throw ParserError.noSectionDefined}
+        guard let prop = currentProperty else { throw ParserError.noPropertyDefined }
+        // No comment stripping on continuation lines — they're part of the value
+        let trimmed = line.trimmingCharacters(in: .whitespaces)
+        let existing = sections[currentSection!]?[prop] ?? ""
+
+        if existing.isEmpty || existing.hasPrefix("\n") {
+            // This is a sub-property line — validate it has a non-empty key
+            guard trimmed.contains("=") else { throw ParserError.missingEqualsSignInSubProperty }
+            let eqIdx = trimmed.firstIndex(of: "=")!
+            let subKey = String(trimmed[..<eqIdx]).trimmingCharacters(in: .whitespaces)
+            guard !subKey.isEmpty else { throw ParserError.emptySubPropertyKey }  // new case needed
+            sections[currentSection!]?[prop] = existing + "\n" + trimmed
+            return
+        }
+
+        // If the parent property has no value (subsection placeholder),
+        // continuation lines must be "key = value" sub-properties
+        if existing.isEmpty && !trimmed.contains("=") {
+            throw ParserError.missingEqualsSignInSubProperty
+        }
+        sections[currentSection!]?[prop] = existing.isEmpty ? "\n" + trimmed : existing + "\n" + trimmed
+    }
+}