Properly compute hashes on Linux by using swift-crypto.

Remove `JSONPointer` and `toJSON`.
Remove CryptoSwift dependency.
Increase minimum macOS version requirement to  10.15 (Catalina).
Increase version number in `main.swift` to 3.0.0.
Update README.

Package.swift

@@ -5,24 +5,27 @@ import PackageDescription
 
 let package = Package(
     name: "LFSPointers",
-	platforms: [.macOS(.v10_13)],
+	platforms: [.macOS(.v10_15)],
 	products: [
 		.executable(name: "LFSPointers", targets: ["LFSPointersExecutable"]),
 		.library(name: "LFSPointersKit", targets: ["LFSPointersKit"])
 	],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
-		.package(url: "https://github.com/krzyzanowskim/CryptoSwift", .exact("1.3.2")),
 		.package(url: "https://github.com/apple/swift-argument-parser.git", from: "0.3.1"),
 		.package(url: "https://github.com/onevcat/Rainbow", from: "3.1.5"),
-		.package(url: "https://github.com/JohnSundell/Files", from: "4.1.1")
+		.package(url: "https://github.com/JohnSundell/Files", from: "4.1.1"),
+		.package(url: "https://github.com/apple/swift-crypto.git", from: "1.1.2")
     ],
     targets: [
         // Targets are the basic building blocks of a package. A target can define a module or a test suite.
         // Targets can depend on other targets in this package, and on products in packages which this package depends on.
         .target(
             name: "LFSPointersKit",
-			dependencies: ["Files", "CryptoSwift"]
+			dependencies: [
+				"Files",
+				.product(name: "Crypto", package: "swift-crypto")
+			]
 		),
 		.target(
 			name: "LFSPointersExecutable",

README.md

@@ -153,7 +153,7 @@ $ LFSPointers --generate-completion-script bash > ~/.bash_completions/LFSPointer
 Add this to the `dependencies` array in `Package.swift`:
 
 ```swift
-.package(url: "https://github.com/LebJe/LFSPointers.git", from: “2.0.0”)
+.package(url: "https://github.com/LebJe/LFSPointers.git", from: “3.0.0”)
 ```
 . Also add this to the `targets` array in the aforementioned file:
 
@@ -241,7 +241,7 @@ let pointer = try LFSPointer(...)
 try JSONEncoder().encode(pointer)
 ```
 
-and to convert an array of tuples consisting of filename, file path, and pointer:
+and to convert an array of `LFSPointer`s:
 
 ```swift
 let pointers = try LFSPointer.pointers(...)

Sources/LFSPointersExecutable/main.swift

@@ -32,7 +32,7 @@ struct LFSPointersCommand: ParsableCommand {
 		commandName: "LFSPointers",
 		abstract: "Replaces large files in a Git repository directory with Git LFS pointers.",
 		discussion: "JSON STRUCTURE:\n\(jsonStructure)",
-		version: "2.0.0"
+		version: "3.0.0"
 	)
 
 	@Flag(name: .shortAndLong, help: "Whether to display verbose output.")

Sources/LFSPointersKit/Extensions.swift

@@ -14,3 +14,22 @@ public extension NSRegularExpression {
 		firstMatch(in: string, options: [], range: NSRange(location: 0, length: string.utf16.count)) != nil
 	}
 }
+
+// From: https://github.com/apple/swift-crypto/blob/8f4bfa5bc1951440c15710e9e893721aa4b2765c/Sources/crypto-shasum/main.swift#L73
+public extension String {
+	init(hexEncoding data: Data) {
+		self = data.map { byte in
+			let s = String(byte, radix: 16)
+			switch s.count {
+				case 0:
+					return "00"
+				case 1:
+					return "0" + s
+				case 2:
+					return s
+				default:
+					fatalError("Weirdly hex encoded byte")
+			}
+		}.joined()
+	}
+}

Sources/LFSPointersKit/Pointers.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 import Files
-import CryptoSwift
+import Crypto
 
 /// Represents a Git LFS pointer for a file.
 ///
@@ -68,11 +68,25 @@ public struct LFSPointer: Codable, Equatable, Hashable {
 		let file = try File(path: path.path)
 
 		self.version = "https://git-lfs.github.com/spec/v1"
-
-		self.oid = try FileHandle(forReadingFrom: file.url).availableData.sha256().toHexString()
+
+		let handle = try FileHandle(forReadingFrom: file.url)
+
+		let readSize = 8192
+		var hasher = SHA256()
+
+		while true {
+			let data = handle.readData(ofLength: readSize)
+			if data.count == 0 {
+				break
+			}
+
+			hasher.update(data: data)
+		}
+
+		self.oid = String(hexEncoding: Data(hasher.finalize()))
 
 		let attr = try FileManager.default.attributesOfItem(atPath: file.path)
-		
+
 		self.size = (attr[.size] as? Int) ?? 0
 
 		self.filename = file.name
@@ -259,28 +273,6 @@ extension LFSPointer: CustomDebugStringConvertible {
 	}
 }
 
-public struct JSONPointer: Codable {
-	public let filename: String
-	public let filePath: String
-	public let pointer: LFSPointer
-}
-
-/// Generates a string containing `JSON`.
-/// - Parameter array: No description.
-/// - Returns: A `String` containing `JSON`.
-public func toJSON(array: [JSONPointer], jsonFormat: JSONEncoder.OutputFormatting = .init()) -> String {
-
-	let encoder = JSONEncoder()
-
-	encoder.outputFormatting = jsonFormat
-
-	let jsonBytes = (try? encoder.encode(array)) ?? Data()
-
-	let jsonString = String(data: jsonBytes, encoding: .utf8) ?? ""
-
-	return jsonString
-}
-
 public extension Array where Self.Element == LFSPointer {
 	/// Converts and `Array` of `LFSPointer`s to `JSON`.
 	/// - Parameter jsonFormat: The format of the generated `JSON`.

Tests/LFSPointersTests/LFSPointersTests.swift

@@ -8,11 +8,9 @@ final class LFSPointersTests: XCTestCase {
 
 	func testConvertFileToPointer() throws {
 		let pointer = try LFSPointer(fromFile: resources.file(named: "foo.txt").url)
-
-		#if os(macOS)
+
 		XCTAssertEqual(667684, pointer.size)
 		XCTAssertEqual("802cd848ada6f6f7177bc4bd0952e2c3a5c7378757899b1ed16c0f1a243eb930", pointer.oid)
-		#endif
     }
 
 	func testRecursivelyGeneratePointersForFilesInSubdirectories() throws {