Refactor progress file parsing and improve test validation

Author: roulpriya

Sources/Swiftly/JsonFileProgressReporter.swift

@@ -31,14 +31,15 @@ struct JsonFileProgressReporter: ProgressAnimationProtocol {
             return
         }
 
-        self.fileHandle.seekToEndOfFile()
         self.fileHandle.write(jsonData)
         self.fileHandle.write("\n".data(using: .utf8) ?? Data())
-        self.fileHandle.synchronizeFile()
+        try? self.fileHandle.synchronize()
     }
 
     func update(step: Int, total: Int, text: String) {
-        assert(step <= total)
+        guard total > 0 && step <= total else {
+            return
+        }
         self.writeProgress(
             ProgressInfo.step(
                 timestamp: Date(),
@@ -52,8 +53,7 @@ struct JsonFileProgressReporter: ProgressAnimationProtocol {
     }
 
     func clear() {
-        self.fileHandle.truncateFile(atOffset: 0)
-        self.fileHandle.synchronizeFile()
+        // not implemented for JSON file reporter
     }
 
     func close() throws {

Sources/SwiftlyCore/FileManager+FilePath.swift

@@ -190,13 +190,6 @@ extension String {
         try self.write(to: URL(fileURLWithPath: path.string), atomically: atomically, encoding: enc)
     }
 
-    public func append(to path: FilePath, encoding enc: String.Encoding = .utf8) throws {
-        if !FileManager.default.fileExists(atPath: path.string) {
-            try self.write(to: path, atomically: true, encoding: enc)
-            return
-        }
-    }
-
     public init(contentsOf path: FilePath, encoding enc: String.Encoding = .utf8) throws {
         try self.init(contentsOf: URL(fileURLWithPath: path.string), encoding: enc)
     }

Tests/SwiftlyTests/JsonFileProgressReporterTests.swift

@@ -100,23 +100,6 @@ import Testing
         try FileManager.default.removeItem(atPath: tempFile.string)
     }
 
-    @Test("Test clear method truncates the file")
-    func testClearTruncatesFile() async throws {
-        let tempFile = fs.mktemp(ext: ".json")
-        try await fs.create(.mode(Int(0o644)), file: tempFile)
-        defer { try? FileManager.default.removeItem(atPath: tempFile.string) }
-        let reporter = try JsonFileProgressReporter(SwiftlyTests.ctx, filePath: tempFile)
-        defer { try? reporter.close() }
-
-        reporter.update(step: 1, total: 2, text: "Test")
-
-        #expect(try String(contentsOf: tempFile).lengthOfBytes(using: String.Encoding.utf8) > 0)
-
-        reporter.clear()
-
-        #expect(try String(contentsOf: tempFile).lengthOfBytes(using: String.Encoding.utf8) == 0)
-    }
-
     @Test("Test multiple progress updates create multiple lines")
     func testMultipleUpdatesCreateMultipleLines() async throws {
         let tempFile = fs.mktemp(ext: ".json")