feat: Improves configuring imports for codegen (#541)

* targets file based config branch for CRT

* Adds param for spiName for imports

* Updates ImportDeclarations to allow for the usage of _spiName

* reverts pacakge

* bumps package.swift

* Asserts that only Internal spi name can be used currently

* ktlint

Author: Ed Paulosky

Package.swift

@@ -13,7 +13,7 @@ let package = Package(
         .library(name: "SmithyTestUtil", targets: ["SmithyTestUtil"])
     ],
     dependencies: [
-        .package(url: "https://github.com/awslabs/aws-crt-swift.git", .exact("0.6.1")),
+        .package(url: "https://github.com/awslabs/aws-crt-swift.git", .exact("0.9.0")),
         .package(url: "https://github.com/apple/swift-log.git", from: "1.0.0"),
         .package(url: "https://github.com/MaxDesiatov/XMLCoder.git", from: "0.13.0")
     ],

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

@@ -8,8 +8,31 @@ package software.amazon.smithy.swift.codegen
 class ImportDeclarations {
     private val imports = mutableSetOf<ImportStatement>()
 
-    fun addImport(packageName: String, isTestable: Boolean = false) {
-        imports.add(ImportStatement(packageName, isTestable))
+    fun addImport(packageName: String, isTestable: Boolean = false, internalSPIName: String? = null) {
+        if (internalSPIName != null && internalSPIName != "Internal") {
+            throw IllegalArgumentException(
+                """
+                We currently only support usage of a single spiName 'Internal'. 
+                If you'd like to use another name then please update the logic below to fully support multiple spiNames.
+                """
+            )
+        }
+
+        val existingImport = imports.find { it.packageName == packageName }
+        if (existingImport != null) {
+            // If we have an existing import with the same package name, then replace the existing one
+            val newImport = ImportStatement(
+                packageName,
+                isTestable || existingImport.isTestable,
+                internalSPIName ?: existingImport.internalSPIName
+            )
+            imports.remove(existingImport)
+            imports.add(newImport)
+            return
+        }
+
+        // Otherwise, we have a new import so add it
+        imports.add(ImportStatement(packageName, isTestable, internalSPIName))
     }
 
     override fun toString(): String {
@@ -18,19 +41,23 @@ class ImportDeclarations {
         }
 
         return imports
+            .sortedBy { it.packageName }
             .map(ImportStatement::statement)
-            .sorted()
             .joinToString(separator = "\n")
     }
 }
 
-private data class ImportStatement(val packageName: String, val isTestable: Boolean) {
+private data class ImportStatement(val packageName: String, val isTestable: Boolean, val internalSPIName: String?) {
     val statement: String
         get() {
+            var import = "import $packageName"
+            if (internalSPIName != null) {
+                import = "@_spi($internalSPIName) $import"
+            }
             if (isTestable) {
-                return "@testable import $packageName"
+                import = "@testable $import"
             }
-            return "import $packageName"
+            return import
         }
 
     override fun toString(): String = statement

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

@@ -90,20 +90,19 @@ class SwiftWriter(private val fullPackageName: String) : CodeWriter() {
         val staticHeader: String = "// Code generated by smithy-swift-codegen. DO NOT EDIT!\n\n"
     }
 
-    fun addImport(symbol: Symbol) {
-
+    fun addImport(symbol: Symbol, internalSPIName: String? = null) {
         if (symbol.isBuiltIn || symbol.isServiceNestedNamespace) return
         // always add dependencies
         dependencies.addAll(symbol.dependencies)
 
         // only add imports for symbols that exist in a certain namespace
         if (symbol.namespace.isNotEmpty()) {
-            imports.addImport(symbol.namespace, false)
+            imports.addImport(symbol.namespace, false, internalSPIName)
         }
     }
 
-    fun addImport(packageName: String, isTestable: Boolean = false) {
-        imports.addImport(packageName, isTestable)
+    fun addImport(packageName: String, isTestable: Boolean = false, internalSPIName: String? = null) {
+        imports.addImport(packageName, isTestable, internalSPIName)
     }
 
     fun addFoundationImport() {