feat: add utility method for converting SdkHttpRequest to URLRequest. (#613)

* Add extension constructor to URLRequest to convert SDKHttpRequest

* Add preprocessor conditional import functionality to SwiftWriter.

---------

Co-authored-by: Sichan Yoo <[email protected]>

Author: sichanyoo

Sources/ClientRuntime/Networking/Http/SdkHttpRequest.swift

@@ -6,6 +6,12 @@ import struct Foundation.CharacterSet
 import struct Foundation.URLQueryItem
 import struct Foundation.URLComponents
 import AwsCommonRuntimeKit
+// In Linux, Foundation.URLRequest is moved to FoundationNetworking.
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#else
+import struct Foundation.URLRequest
+#endif
 
 // we need to maintain a reference to this same request while we add headers
 // in the CRT engine so that is why it's a class
@@ -85,6 +91,30 @@ extension SdkHttpRequest {
     }
 }
 
+public extension URLRequest {
+    init(sdkRequest: SdkHttpRequest) async throws {
+        // Set URL
+        guard let url = sdkRequest.endpoint.url else {
+            throw ClientError.dataNotFound("Failed to construct URLRequest due to missing URL.")
+        }
+        self.init(url: url)
+        // Set method type
+        self.httpMethod = sdkRequest.method.rawValue
+        // Set body, handling any serialization errors
+        do {
+            self.httpBody = try await sdkRequest.body.readData()
+        } catch {
+            throw ClientError.serializationFailed("Failed to construct URLRequest due to HTTP body conversion failure.")
+        }
+        // Set headers
+        sdkRequest.headers.headers.forEach { header in
+            header.value.forEach { value in
+                self.addValue(value, forHTTPHeaderField: header.name)
+            }
+        }
+    }
+}
+
 extension SdkHttpRequest: CustomDebugStringConvertible, CustomStringConvertible {
 
     public var debugDescriptionWithBody: String {

Tests/ClientRuntimeTests/NetworkingTests/HttpRequestTests.swift

@@ -7,6 +7,12 @@ import XCTest
 import AwsCommonRuntimeKit
 import struct Foundation.URLQueryItem
 @testable import ClientRuntime
+// In Linux, Foundation.URLRequest is moved to FoundationNetworking.
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#else
+import struct Foundation.URLRequest
+#endif
 
 class HttpRequestTests: NetworkingTestUtils {
 
@@ -51,6 +57,30 @@ class HttpRequestTests: NetworkingTestUtils {
         }
     }
 
+    func testSdkHttpRequestToURLRequest() async throws {
+        let headers = Headers(["Testname-1": "testvalue-1", "Testname-2": "testvalue-2"])
+        let endpoint = Endpoint(host: "host.com", path: "/", headers: headers)
+
+        let httpBody = HttpBody.data(expectedMockRequestData)
+        let mockHttpRequest = SdkHttpRequest(method: .get, endpoint: endpoint, body: httpBody)
+        let urlRequest = try await URLRequest(sdkRequest: mockHttpRequest)
+
+        XCTAssertNotNil(urlRequest)
+        guard let headersFromRequest = urlRequest.allHTTPHeaderFields else {
+            XCTFail("Headers in SdkHttpRequest were not successfully converted to headers in URLRequest.")
+            // Compiler doesn't recognize XCTFail as return / exception thrown
+            return
+        }
+
+        // Check URLRequest fields
+        XCTAssertTrue(headersFromRequest.contains { $0.key == "Testname-1" && $0.value == "testvalue-1" })
+        XCTAssertTrue(headersFromRequest.contains { $0.key == "Testname-2" && $0.value == "testvalue-2" })
+        let expectedBody = try await httpBody.readData()
+        XCTAssertEqual(urlRequest.httpBody, expectedBody)
+        XCTAssertEqual(urlRequest.url, endpoint.url)
+        XCTAssertEqual(urlRequest.httpMethod, mockHttpRequest.method.rawValue)
+    }
+
     func testCRTHeadersToSdkHeaders() throws {
         let builder = SdkHttpRequestBuilder()
             .withHeader(name: "Host", value: "amazon.aws.com")

smithy-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/ImportDeclarations.kt

@@ -8,7 +8,12 @@ package software.amazon.smithy.swift.codegen
 class ImportDeclarations {
     private val imports = mutableSetOf<ImportStatement>()
 
-    fun addImport(packageName: String, isTestable: Boolean = false, internalSPIName: String? = null) {
+    fun addImport(
+        packageName: String,
+        isTestable: Boolean = false,
+        internalSPIName: String? = null,
+        importOnlyIfCanImport: Boolean = false
+    ) {
         val existingImport = imports.find { it.packageName == packageName }
         if (existingImport != null) {
             // Update isTestable to true if needed
@@ -17,10 +22,12 @@ class ImportDeclarations {
             if (internalSPIName != null) {
                 existingImport.internalSPINames.add(internalSPIName)
             }
+            // Update importOnlyIfCanImport to true if needed
+            existingImport.importOnlyIfCanImport = existingImport.importOnlyIfCanImport || importOnlyIfCanImport
         } else {
             // Otherwise, we have a new package to import, so add it
             val internalSPINames = listOf(internalSPIName).mapNotNull { it }.toMutableSet()
-            imports.add(ImportStatement(packageName, isTestable, internalSPINames))
+            imports.add(ImportStatement(packageName, isTestable, internalSPINames, importOnlyIfCanImport))
         }
     }
 
@@ -36,7 +43,12 @@ class ImportDeclarations {
     }
 }
 
-private data class ImportStatement(val packageName: String, var isTestable: Boolean, val internalSPINames: MutableSet<String>) {
+private data class ImportStatement(
+    val packageName: String,
+    var isTestable: Boolean,
+    val internalSPINames: MutableSet<String>,
+    var importOnlyIfCanImport: Boolean
+) {
     val statement: String
         get() {
             var import = "import $packageName"
@@ -46,6 +58,14 @@ private data class ImportStatement(val packageName: String, var isTestable: Bool
             if (isTestable) {
                 import = "@testable $import"
             }
+            if (importOnlyIfCanImport) {
+                import =
+                    """
+                    #if canImport($packageName)
+                    $import
+                    #endif
+                    """.trimIndent()
+            }
             return import
         }
 

smithy-swift-codegen/src/main/kotlin/software/amazon/smithy/swift/codegen/SwiftWriter.kt

@@ -101,8 +101,13 @@ class SwiftWriter(private val fullPackageName: String) : CodeWriter() {
         }
     }
 
-    fun addImport(packageName: String, isTestable: Boolean = false, internalSPIName: String? = null) {
-        imports.addImport(packageName, isTestable, internalSPIName)
+    fun addImport(
+        packageName: String,
+        isTestable: Boolean = false,
+        internalSPIName: String? = null,
+        importOnlyIfCanImport: Boolean = false
+    ) {
+        imports.addImport(packageName, isTestable, internalSPIName, importOnlyIfCanImport)
     }
 
     fun addFoundationImport() {