handle exceptions by throwing, not with results

lib/api.dart

@@ -5,7 +5,6 @@ import 'package:flutter/foundation.dart';
 import 'package:http/http.dart' as http;
 import 'package:logging/logging.dart';
 import 'package:path_provider/path_provider.dart'; // For cache storage
-import 'package:sheetless/utility.dart';
 
 import 'sheet.dart';
 
@@ -16,31 +15,22 @@ class ApiClient {
 
   ApiClient({required this.baseUrl, this.token});
 
-  Future<Result<void>> login(String username, String password) async {
+  Future<void> login(String username, String password) async {
     log.info("Logging in...");
-    try {
+    final url = '$baseUrl/login';
-      final url = '$baseUrl/login';
+    final response = await http.post(
-      final response = await http.post(
+      Uri.parse(url),
-        Uri.parse(url),
+      headers: {'Content-Type': 'application/json'},
-        headers: {'Content-Type': 'application/json'},
+      body: jsonEncode({'email': username, 'password': password}),
-        body: jsonEncode({'email': username, 'password': password}),
+    );
-      );
 
-      if (response.statusCode == 200) {
+    if (response.statusCode == 200) {
-        token = jsonDecode(response.body);
+      token = jsonDecode(response.body);
-        log.info('Login successful');
+      log.info('Login successful');
-        return Result.ok(null);
+    } else {
-      } else {
+      throw Exception(
-        log.warning('Login failed: ${response.statusCode}, ${response.body}');
+        "Failed logging in: Response code ${response.statusCode}\nResponse: ${response.body}",
-        return Result.error(
+      );
-          Exception(
-            "Response code ${response.statusCode}\nResponse: ${response.body}",
-          ),
-        );
-      }
-    } on Exception catch (e) {
-      log.warning('Error during login', e);
-      return Result.error(e);
     }
   }
 
@@ -49,27 +39,26 @@ class ApiClient {
     log.info('Logged out successfully.');
   }
 
-  Future<http.Response?> get(String endpoint, {bool isBinary = false}) async {
+  Future<http.Response> get(
-    try {
+    String endpoint, {
-      final url = '$baseUrl$endpoint';
+    bool isBinary = false,
-      final headers = {
+    bool throwExceptionIfStatusCodeNot200 = false,
-        'Authorization': 'Bearer $token',
+  }) async {
-        if (!isBinary) 'Content-Type': 'application/json',
+    final url = '$baseUrl$endpoint';
-      };
+    final headers = {
+      'Authorization': 'Bearer $token',
+      if (!isBinary) 'Content-Type': 'application/json',
+    };
 
-      final response = await http.get(Uri.parse(url), headers: headers);
+    final response = await http.get(Uri.parse(url), headers: headers);
 
-      if (response.statusCode == 200) {
+    if (!throwExceptionIfStatusCodeNot200 || response.statusCode == 200) {
-        return response;
+      return response;
-      } else {
+    } else {
-        log.warning(
+      throw Exception(
-          'GET request failed: ${response.statusCode} ${response.body}',
+        'GET request failed: ${response.statusCode} ${response.body}',
-        );
+      );
-      }
-    } catch (e) {
-      log.warning('Error during GET request', e);
     }
-    return null;
   }
 
   Future<http.Response?> post(
@@ -130,71 +119,41 @@ class ApiClient {
   }
 
   Future<List<Sheet>> fetchSheets() async {
-    try {
+    final response = await get(
-      final response = await get("/list/sheets");
+      "/list/sheets",
+      throwExceptionIfStatusCodeNot200: true,
+    );
 
-      if (response == null) {
+    final data = jsonDecode(response.body);
-        return List.empty();
+    return (data as List<dynamic>)
-      }
+        .map((sheet) => Sheet.fromJson(sheet as Map<String, dynamic>))
-
+        .toList();
-      if (response.statusCode == 200) {
-        final data = jsonDecode(response.body);
-        return (data as List<dynamic>)
-            .map((sheet) => Sheet.fromJson(sheet as Map<String, dynamic>))
-            .toList();
-      } else {
-        log.warning(
-          'Failed to fetch sheets with status: ${response.statusCode}',
-        );
-        log.info('Response: ${response.body}');
-      }
-    } catch (e) {
-      log.warning('Error during fetching sheets', e);
-    }
-
-    return List.empty();
   }
 
-  Future<Uint8List?> fetchPdfFileData(String sheetUuid) async {
+  Future<Uint8List> fetchPdfFileData(String sheetUuid) async {
-    try {
+    final response = await get(
-      final response = await get('/sheet/pdf/$sheetUuid', isBinary: true);
+      '/sheet/pdf/$sheetUuid',
+      isBinary: true,
+      throwExceptionIfStatusCodeNot200: true,
+    );
 
-      if (response != null && response.statusCode == 200) {
+    log.info("PDF downloaded");
-        log.info("PDF downloaded");
+    return response.bodyBytes;
-        return response.bodyBytes;
-      } else {
-        log.warning(
-          "Failed to fetch PDF from API. Status: ${response?.statusCode}",
-        );
-      }
-    } catch (e) {
-      log.warning("Error fetching PDF", e);
-    }
-
-    return null;
   }
 
-  Future<File?> getPdfFileCached(String sheetUuid) async {
+  Future<File> getPdfFileCached(String sheetUuid) async {
-    try {
+    final cacheDir = await getTemporaryDirectory();
-      final cacheDir = await getTemporaryDirectory();
+    final cachedPdfPath = '${cacheDir.path}/$sheetUuid.pdf';
-      final cachedPdfPath = '${cacheDir.path}/$sheetUuid.pdf';
 
-      final cachedFile = File(cachedPdfPath);
+    final cachedFile = File(cachedPdfPath);
-      if (await cachedFile.exists()) {
+    if (await cachedFile.exists()) {
-        log.info("PDF found in cache: $cachedPdfPath");
+      log.info("PDF found in cache: $cachedPdfPath");
-        return cachedFile;
-      }
-
-      final pdfFileData = await fetchPdfFileData(sheetUuid);
-      await cachedFile.writeAsBytes(
-        pdfFileData!,
-      ); // TODO: proper error handling
-      log.info("PDF cached at: $cachedPdfPath");
       return cachedFile;
-    } catch (e) {
-      log.warning("Error fetching PDF", e);
     }
 
-    return null;
+    final pdfFileData = await fetchPdfFileData(sheetUuid);
+    await cachedFile.writeAsBytes(pdfFileData);
+    log.info("PDF cached at: $cachedPdfPath");
+    return cachedFile;
   }
 }

lib/home_page.dart

@@ -106,6 +106,7 @@ class _MyHomePageState extends State<MyHomePage> {
               },
             );
           } else if (snapshot.hasError) {
+            log.warning("Error loading sheets:", snapshot.error);
             return Center(
               child: Text(
                 style: Theme.of(

lib/login_page.dart

@@ -63,15 +63,16 @@ class _LoginPageState extends State<LoginPage> {
       _error = null;
     });
     final apiClient = ApiClient(baseUrl: "$serverUrl/api");
-    final loginResult = await apiClient.login(email, password);
+    try {
-    if (loginResult.isOk()) {
+      await apiClient.login(email, password);
+
       await _storageHelper.writeSecure(SecureStorageKey.url, serverUrl);
       await _storageHelper.writeSecure(SecureStorageKey.jwt, apiClient.token!);
       await _storageHelper.writeSecure(SecureStorageKey.email, email);
       await _navigateToMainPage();
-    } else {
+    } catch (e) {
       setState(() {
-        _error = "Login failed.\n${loginResult.error()}";
+        _error = "Login failed.\n$e";
       });
     }
   }

lib/sheet_viewer_page.dart

@@ -60,17 +60,11 @@ class _SheetViewerPageState extends State<SheetViewerPage>
 
   Future<bool> loadPdf() async {
     if (kIsWeb) {
-      var data = await widget.apiClient.fetchPdfFileData(widget.sheet.uuid);
+      final data = await widget.apiClient.fetchPdfFileData(widget.sheet.uuid);
-      if (data == null) {
-        throw Exception("Failed fetching pdf file");
-      }
 
       document = await PdfDocument.openData(data);
     } else {
-      var file = await widget.apiClient.getPdfFileCached(widget.sheet.uuid);
+      final file = await widget.apiClient.getPdfFileCached(widget.sheet.uuid);
-      if (file == null) {
-        throw Exception("Failed fetching pdf file");
-      }
 
       document = await PdfDocument.openFile(file.path);
     }
@@ -181,6 +175,7 @@ class _SheetViewerPageState extends State<SheetViewerPage>
                 ],
               );
             } else if (snapshot.hasError) {
+              log.warning("Error loading pdf:", snapshot.error);
               return Center(
                 child: Text(
                   style: Theme.of(

lib/utility.dart

@@ -1,70 +0,0 @@
-/// Utility class that simplifies handling errors.
-///
-/// Return a [Result] from a function to indicate success or failure.
-///
-/// A [Result] is either an [Ok] with a value of type [T]
-/// or an [Err] with an [Exception].
-///
-/// Use [Result.ok] to create a successful result with a value of type [T].
-/// Use [Result.error] to create an error result with an [Exception].
-///
-/// Evaluate the result using a switch statement:
-/// ```dart
-/// switch (result) {
-///   case Ok(): {
-///     print(result.value);
-///   }
-///   case Error(): {
-///     print(result.error);
-///   }
-/// }
-/// ```
-sealed class Result<T> {
-  const Result();
-
-  /// Creates a successful [Result], completed with the specified [value].
-  const factory Result.ok(T value) = Ok._;
-
-  /// Creates an error [Result], completed with the specified [error].
-  const factory Result.error(Exception error) = Err._;
-
-  bool isOk() {
-    return this is Ok;
-  }
-
-  T value() {
-    Ok<T> ok = this as Ok<T>;
-    return ok._value;
-  }
-
-  bool isErr() {
-    return this is Err;
-  }
-
-  Exception error() {
-    Err<T> err = this as Err<T>;
-    return err._error;
-  }
-}
-
-/// A successful [Result] with a returned [value].
-final class Ok<T> extends Result<T> {
-  const Ok._(this._value);
-
-  /// The returned value of this result.
-  final T _value;
-
-  @override
-  String toString() => 'Result<$T>.ok($_value)';
-}
-
-/// An error [Result] with a resulting [error].
-final class Err<T> extends Result<T> {
-  const Err._(this._error);
-
-  /// The resulting error of this result.
-  final Exception _error;
-
-  @override
-  String toString() => 'Result<$T>.error($_error)';
-}