Add SerializedJSON type as string literal escaping helper

Sources/Basics/ByteString+Extensions.swift

@@ -23,4 +23,8 @@ extension ByteString {
     public var sha256Checksum: String {
         SHA256().hash(self).hexadecimalRepresentation
     }
+
+    public init(json: SerializedJSON) {
+        self.init(json.underlying.utf8)
+    }
 }

Sources/Basics/CMakeLists.txt

@@ -27,6 +27,7 @@ add_library(Basics
   Errors.swift
   FileSystem/AbsolutePath.swift
   FileSystem/FileSystem+Extensions.swift
+  FileSystem/NativePathExtensions.swift
   FileSystem/RelativePath.swift
   FileSystem/TemporaryFile.swift
   FileSystem/TSCAdapters.swift
@@ -45,12 +46,12 @@ add_library(Basics
   ImportScanning.swift
   JSON+Extensions.swift
   JSONDecoder+Extensions.swift
-  NativePathExtensions.swift
   Netrc.swift
   Observability.swift
   SQLite.swift
   Sandbox.swift
   SendableTimeInterval.swift
+  Serialization/SerializedJSON.swift
   String+Extensions.swift
   SwiftVersion.swift
   SQLiteBackedCache.swift

Sources/Basics/NativePathExtensions.swift → Sources/Basics/FileSystem/NativePathExtensions.swift

@@ -24,3 +24,15 @@ extension AbsolutePath {
         }
     }
 }
+
+extension DefaultStringInterpolation {
+    public mutating func appendInterpolation(_ value: AbsolutePath) {
+        self.appendInterpolation(value._nativePathString(escaped: false))
+    }
+}
+
+extension SerializedJSON.StringInterpolation {
+    public mutating func appendInterpolation(_ value: AbsolutePath) {
+        self.appendInterpolation(value._nativePathString(escaped: false))
+    }
+}

Sources/Basics/Serialization/SerializedJSON.swift

@@ -0,0 +1,49 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2023 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/// Wrapper type representing serialized escaped JSON strings providing helpers
+/// for escaped string interpolations for common types such as `AbsolutePath`.
+public struct SerializedJSON {
+    let underlying: String
+}
+
+extension SerializedJSON: ExpressibleByStringLiteral {
+    public init(stringLiteral: String) {
+        self.underlying = stringLiteral
+    }
+}
+
+extension SerializedJSON: ExpressibleByStringInterpolation {
+    public init(stringInterpolation: StringInterpolation) {
+        self.init(underlying: stringInterpolation.value)
+    }
+
+    public struct StringInterpolation: StringInterpolationProtocol {
+        fileprivate var value: String = ""
+
+        private func escape(_ string: String) -> String {
+            string.replacingOccurrences(of: #"\"#, with: #"\\"#)
+        }
+
+        public init(literalCapacity: Int, interpolationCount: Int) {
+            self.value.reserveCapacity(literalCapacity)
+        }
+
+        public mutating func appendLiteral(_ literal: String) {
+            self.value.append(self.escape(literal))
+        }
+
+        public mutating func appendInterpolation(_ value: some CustomStringConvertible) {
+            self.value.append(self.escape(value.description))
+        }
+    }
+}

Tests/BasicsTests/Serialization/SerializedJSONTests.swift

@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2023 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+@testable import Basics
+import XCTest
+
+final class SerializedJSONTests: XCTestCase {
+    func testPathInterpolation() throws {
+        var path = try AbsolutePath(validating: #"/test\backslashes"#)
+        var json: SerializedJSON = "\(path)"
+
+        XCTAssertEqual(json.underlying, #"/test\\backslashes"#)
+
+        #if os(Windows)
+        path = try AbsolutePath(validating: #"\\?\C:\Users"#)
+        json = "\(path)"
+
+        XCTAssertEqual(json.underlying, #"\\\\?\\C:\\Users"#)
+
+        path = try AbsolutePath(validating: #"\\.\UNC\server\share\n\"#)
+        json = "\(path)"
+
+        XCTAssertEqual(json.underlying, #"\\\\.\\UNC\\server\\share\\"#)
+
+        path = try AbsolutePath(validating: #"\??\Volumes{b79de17a-a1ed-4c58-a353-731b7c4885a6}\\"#)
+        json = "\(path)"
+
+        XCTAssertEqual(json.underlying, #"\\??\\Volumes{b79de17a-a1ed-4c58-a353-731b7c4885a6}\\"#)
+        #endif
+    }
+}

Tests/PackageModelTests/SwiftSDKBundleTests.swift

@@ -21,7 +21,7 @@ import class TSCBasic.InMemoryFileSystem
 
 private let testArtifactID = "test-artifact"
 
-private func generateInfoJSON(artifacts: [MockArtifact]) -> String {
+private func generateInfoJSON(artifacts: [MockArtifact]) -> SerializedJSON {
     """
     {
         "artifacts" : {
@@ -68,7 +68,7 @@ private func generateTestFileSystem(bundleArtifacts: [MockArtifact]) throws -> (
             (
                 "\($0.path)/info.json",
                 ByteString(
-                    encodingAsUTF8: generateInfoJSON(artifacts: $0.artifacts)
+                    json: generateInfoJSON(artifacts: $0.artifacts)
                 )
             )
         })