From 39362b4df11483d5dd1bc2843998f5b6ddac3c9a Mon Sep 17 00:00:00 2001
From: Andreas Ley <andreas@andreasley.ch>
Date: Mon, 26 Aug 2024 21:20:03 +0200
Subject: [PATCH] Return empty `ResponseBody` in `FileIO` for empty files
 (#532)

---
 Sources/Hummingbird/Files/FileIO.swift   |  2 ++
 Tests/HummingbirdTests/FileIOTests.swift | 42 ++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/Sources/Hummingbird/Files/FileIO.swift b/Sources/Hummingbird/Files/FileIO.swift
index 3edbafe9..eafdb368 100644
--- a/Sources/Hummingbird/Files/FileIO.swift
+++ b/Sources/Hummingbird/Files/FileIO.swift
@@ -39,6 +39,7 @@ public struct FileIO: Sendable {
     public func loadFile(path: String, context: some RequestContext, chunkLength: Int = NonBlockingFileIO.defaultChunkSize) async throws -> ResponseBody {
         do {
             let stat = try await fileIO.lstat(path: path)
+            guard stat.st_size > 0 else { return .init() }
             return self.readFile(path: path, range: 0...numericCast(stat.st_size - 1), context: context, chunkLength: chunkLength)
         } catch {
             throw HTTPError(.notFound)
@@ -58,6 +59,7 @@ public struct FileIO: Sendable {
     public func loadFile(path: String, range: ClosedRange<Int>, context: some RequestContext, chunkLength: Int = NonBlockingFileIO.defaultChunkSize) async throws -> ResponseBody {
         do {
             let stat = try await fileIO.lstat(path: path)
+            guard stat.st_size > 0 else { return .init() }
             let fileRange: ClosedRange<Int> = 0...numericCast(stat.st_size - 1)
             let range = range.clamped(to: fileRange)
             return self.readFile(path: path, range: range, context: context, chunkLength: chunkLength)
diff --git a/Tests/HummingbirdTests/FileIOTests.swift b/Tests/HummingbirdTests/FileIOTests.swift
index 833ac59a..e7079684 100644
--- a/Tests/HummingbirdTests/FileIOTests.swift
+++ b/Tests/HummingbirdTests/FileIOTests.swift
@@ -90,4 +90,46 @@ class FileIOTests: XCTestCase {
             XCTAssertEqual(Data(buffer: buffer), data)
         }
     }
+
+    func testReadEmptyFile() async throws {
+        let router = Router()
+        router.get("empty.txt") { _, context -> Response in
+            let fileIO = FileIO(threadPool: .singleton)
+            let body = try await fileIO.loadFile(path: "empty.txt", context: context)
+            return .init(status: .ok, headers: [:], body: body)
+        }
+        let data = Data()
+        let fileURL = URL(fileURLWithPath: "empty.txt")
+        XCTAssertNoThrow(try data.write(to: fileURL))
+        defer { XCTAssertNoThrow(try FileManager.default.removeItem(at: fileURL)) }
+
+        let app = Application(responder: router.buildResponder())
+
+        try await app.test(.router) { client in
+            try await client.execute(uri: "/empty.txt", method: .get) { response in
+                XCTAssertEqual(response.status, .ok)
+            }
+        }
+    }
+
+    func testReadEmptyFilePart() async throws {
+        let router = Router()
+        router.get("empty.txt") { _, context -> Response in
+            let fileIO = FileIO(threadPool: .singleton)
+            let body = try await fileIO.loadFile(path: "empty.txt", range: 0...10, context: context)
+            return .init(status: .ok, headers: [:], body: body)
+        }
+        let data = Data()
+        let fileURL = URL(fileURLWithPath: "empty.txt")
+        XCTAssertNoThrow(try data.write(to: fileURL))
+        defer { XCTAssertNoThrow(try FileManager.default.removeItem(at: fileURL)) }
+
+        let app = Application(responder: router.buildResponder())
+
+        try await app.test(.router) { client in
+            try await client.execute(uri: "/empty.txt", method: .get) { response in
+                XCTAssertEqual(response.status, .ok)
+            }
+        }
+    }
 }