[camera] Remove @throw from iOS implementation (flutter#5034)

Using `@throw` in iOS code violates the style guide, so it shouldn't be done in the plugin as mechanism for communicating errors. More importantly, `NSError` is not intended to be used with `@throw`/`@catch`, and is causing issues when compiled with the iOS 17 SDK.

This removes all use of `@throw`, and all `@catch (NSError* e)`, in favor of other methods of communicating errors. It explicitly does not try to fix all the other strange things about this code (having an `NSError` out-param in an init method, using Cocoa and NSURL error domains and codes for some reason), and instead preserves existing behavior as much as possible. In practice, none of these codepaths should ever actually happen (they indicate programming errors within the plugin, not unexpected runtime behavior), and all of this code will go away when converting to Pigeon anyway, so there's not much value in trying to unwind this structure further.

Fixes flutter/flutter#135195

packages/camera/camera_avfoundation/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.9.13+6
+
+* Fixes incorrect use of `NSError` that could cause crashes on launch.
+
 ## 0.9.13+5
 
 * Ignores audio samples until the first video sample arrives.

packages/camera/camera_avfoundation/example/ios/Runner.xcodeproj/project.pbxproj

@@ -280,7 +280,7 @@
 		97C146E61CF9000F007C117D /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastUpgradeCheck = 1300;
+				LastUpgradeCheck = 1430;
 				ORGANIZATIONNAME = "The Flutter Authors";
 				TargetAttributes = {
 					03BB76672665316900CE5A93 = {

packages/camera/camera_avfoundation/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1300"
+   LastUpgradeVersion = "1430"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

packages/camera/camera_avfoundation/example/ios/RunnerTests/CameraPropertiesTests.m

@@ -19,7 +19,7 @@ - (void)testFLTGetFLTFlashModeForString {
   XCTAssertEqual(FLTFlashModeAuto, FLTGetFLTFlashModeForString(@"auto"));
   XCTAssertEqual(FLTFlashModeAlways, FLTGetFLTFlashModeForString(@"always"));
   XCTAssertEqual(FLTFlashModeTorch, FLTGetFLTFlashModeForString(@"torch"));
-  XCTAssertThrows(FLTGetFLTFlashModeForString(@"unkwown"));
+  XCTAssertEqual(FLTFlashModeInvalid, FLTGetFLTFlashModeForString(@"unknown"));
 }
 
 - (void)testFLTGetAVCaptureFlashModeForFLTFlashMode {
@@ -34,27 +34,27 @@ - (void)testFLTGetAVCaptureFlashModeForFLTFlashMode {
 - (void)testFLTGetStringForFLTExposureMode {
   XCTAssertEqualObjects(@"auto", FLTGetStringForFLTExposureMode(FLTExposureModeAuto));
   XCTAssertEqualObjects(@"locked", FLTGetStringForFLTExposureMode(FLTExposureModeLocked));
-  XCTAssertThrows(FLTGetStringForFLTExposureMode(-1));
+  XCTAssertNil(FLTGetStringForFLTExposureMode(-1));
 }
 
 - (void)testFLTGetFLTExposureModeForString {
   XCTAssertEqual(FLTExposureModeAuto, FLTGetFLTExposureModeForString(@"auto"));
   XCTAssertEqual(FLTExposureModeLocked, FLTGetFLTExposureModeForString(@"locked"));
-  XCTAssertThrows(FLTGetFLTExposureModeForString(@"unknown"));
+  XCTAssertEqual(FLTExposureModeInvalid, FLTGetFLTExposureModeForString(@"unknown"));
 }
 
 #pragma mark - focus mode tests
 
 - (void)testFLTGetStringForFLTFocusMode {
   XCTAssertEqualObjects(@"auto", FLTGetStringForFLTFocusMode(FLTFocusModeAuto));
   XCTAssertEqualObjects(@"locked", FLTGetStringForFLTFocusMode(FLTFocusModeLocked));
-  XCTAssertThrows(FLTGetStringForFLTFocusMode(-1));
+  XCTAssertNil(FLTGetStringForFLTFocusMode(-1));
 }
 
 - (void)testFLTGetFLTFocusModeForString {
   XCTAssertEqual(FLTFocusModeAuto, FLTGetFLTFocusModeForString(@"auto"));
   XCTAssertEqual(FLTFocusModeLocked, FLTGetFLTFocusModeForString(@"locked"));
-  XCTAssertThrows(FLTGetFLTFocusModeForString(@"unknown"));
+  XCTAssertEqual(FLTFocusModeInvalid, FLTGetFLTFocusModeForString(@"unknown"));
 }
 
 #pragma mark - resolution preset tests
@@ -67,7 +67,7 @@ - (void)testFLTGetFLTResolutionPresetForString {
   XCTAssertEqual(FLTResolutionPresetVeryHigh, FLTGetFLTResolutionPresetForString(@"veryHigh"));
   XCTAssertEqual(FLTResolutionPresetUltraHigh, FLTGetFLTResolutionPresetForString(@"ultraHigh"));
   XCTAssertEqual(FLTResolutionPresetMax, FLTGetFLTResolutionPresetForString(@"max"));
-  XCTAssertThrows(FLTGetFLTFlashModeForString(@"unknown"));
+  XCTAssertEqual(FLTResolutionPresetInvalid, FLTGetFLTResolutionPresetForString(@"unknown"));
 }
 
 #pragma mark - video format tests
@@ -89,7 +89,7 @@ - (void)testFLTGetUIDeviceOrientationForString {
   XCTAssertEqual(UIDeviceOrientationLandscapeLeft,
                  FLTGetUIDeviceOrientationForString(@"landscapeRight"));
   XCTAssertEqual(UIDeviceOrientationPortrait, FLTGetUIDeviceOrientationForString(@"portraitUp"));
-  XCTAssertThrows(FLTGetUIDeviceOrientationForString(@"unknown"));
+  XCTAssertEqual(UIDeviceOrientationUnknown, FLTGetUIDeviceOrientationForString(@"unknown"));
 }
 
 - (void)testFLTGetStringForUIDeviceOrientation {

packages/camera/camera_avfoundation/ios/Classes/CameraProperties.h

@@ -17,6 +17,9 @@ typedef NS_ENUM(NSInteger, FLTFlashMode) {
   FLTFlashModeAuto,
   FLTFlashModeAlways,
   FLTFlashModeTorch,
+  // This should never occur; it indicates an unknown value was received over
+  // the platform channel.
+  FLTFlashModeInvalid,
 };
 
 /**
@@ -39,6 +42,9 @@ extern AVCaptureFlashMode FLTGetAVCaptureFlashModeForFLTFlashMode(FLTFlashMode m
 typedef NS_ENUM(NSInteger, FLTExposureMode) {
   FLTExposureModeAuto,
   FLTExposureModeLocked,
+  // This should never occur; it indicates an unknown value was received over
+  // the platform channel.
+  FLTExposureModeInvalid,
 };
 
 /**
@@ -61,6 +67,9 @@ extern FLTExposureMode FLTGetFLTExposureModeForString(NSString *mode);
 typedef NS_ENUM(NSInteger, FLTFocusMode) {
   FLTFocusModeAuto,
   FLTFocusModeLocked,
+  // This should never occur; it indicates an unknown value was received over
+  // the platform channel.
+  FLTFocusModeInvalid,
 };
 
 /**
@@ -100,6 +109,9 @@ typedef NS_ENUM(NSInteger, FLTResolutionPreset) {
   FLTResolutionPresetVeryHigh,
   FLTResolutionPresetUltraHigh,
   FLTResolutionPresetMax,
+  // This should never occur; it indicates an unknown value was received over
+  // the platform channel.
+  FLTResolutionPresetInvalid,
 };
 
 /**

packages/camera/camera_avfoundation/ios/Classes/CameraProperties.m

@@ -16,13 +16,7 @@ FLTFlashMode FLTGetFLTFlashModeForString(NSString *mode) {
   } else if ([mode isEqualToString:@"torch"]) {
     return FLTFlashModeTorch;
   } else {
-    NSError *error = [NSError errorWithDomain:NSCocoaErrorDomain
-                                         code:NSURLErrorUnknown
-                                     userInfo:@{
-                                       NSLocalizedDescriptionKey : [NSString
-                                           stringWithFormat:@"Unknown flash mode %@", mode]
-                                     }];
-    @throw error;
+    return FLTFlashModeInvalid;
   }
 }
 
@@ -48,14 +42,11 @@ AVCaptureFlashMode FLTGetAVCaptureFlashModeForFLTFlashMode(FLTFlashMode mode) {
       return @"auto";
     case FLTExposureModeLocked:
       return @"locked";
+    case FLTExposureModeInvalid:
+      // This value should never actually be used.
+      return nil;
   }
-  NSError *error = [NSError errorWithDomain:NSCocoaErrorDomain
-                                       code:NSURLErrorUnknown
-                                   userInfo:@{
-                                     NSLocalizedDescriptionKey : [NSString
-                                         stringWithFormat:@"Unknown string for exposure mode"]
-                                   }];
-  @throw error;
+  return nil;
 }
 
 FLTExposureMode FLTGetFLTExposureModeForString(NSString *mode) {
@@ -64,13 +55,7 @@ FLTExposureMode FLTGetFLTExposureModeForString(NSString *mode) {
   } else if ([mode isEqualToString:@"locked"]) {
     return FLTExposureModeLocked;
   } else {
-    NSError *error = [NSError errorWithDomain:NSCocoaErrorDomain
-                                         code:NSURLErrorUnknown
-                                     userInfo:@{
-                                       NSLocalizedDescriptionKey : [NSString
-                                           stringWithFormat:@"Unknown exposure mode %@", mode]
-                                     }];
-    @throw error;
+    return FLTExposureModeInvalid;
   }
 }
 
@@ -82,14 +67,11 @@ FLTExposureMode FLTGetFLTExposureModeForString(NSString *mode) {
       return @"auto";
     case FLTFocusModeLocked:
       return @"locked";
+    case FLTFocusModeInvalid:
+      // This value should never actually be used.
+      return nil;
   }
-  NSError *error = [NSError errorWithDomain:NSCocoaErrorDomain
-                                       code:NSURLErrorUnknown
-                                   userInfo:@{
-                                     NSLocalizedDescriptionKey : [NSString
-                                         stringWithFormat:@"Unknown string for focus mode"]
-                                   }];
-  @throw error;
+  return nil;
 }
 
 FLTFocusMode FLTGetFLTFocusModeForString(NSString *mode) {
@@ -98,13 +80,7 @@ FLTFocusMode FLTGetFLTFocusModeForString(NSString *mode) {
   } else if ([mode isEqualToString:@"locked"]) {
     return FLTFocusModeLocked;
   } else {
-    NSError *error = [NSError errorWithDomain:NSCocoaErrorDomain
-                                         code:NSURLErrorUnknown
-                                     userInfo:@{
-                                       NSLocalizedDescriptionKey : [NSString
-                                           stringWithFormat:@"Unknown focus mode %@", mode]
-                                     }];
-    @throw error;
+    return FLTFocusModeInvalid;
   }
 }
 
@@ -120,14 +96,7 @@ UIDeviceOrientation FLTGetUIDeviceOrientationForString(NSString *orientation) {
   } else if ([orientation isEqualToString:@"portraitUp"]) {
     return UIDeviceOrientationPortrait;
   } else {
-    NSError *error = [NSError
-        errorWithDomain:NSCocoaErrorDomain
-                   code:NSURLErrorUnknown
-               userInfo:@{
-                 NSLocalizedDescriptionKey :
-                     [NSString stringWithFormat:@"Unknown device orientation %@", orientation]
-               }];
-    @throw error;
+    return UIDeviceOrientationUnknown;
   }
 }
 
@@ -163,13 +132,7 @@ FLTResolutionPreset FLTGetFLTResolutionPresetForString(NSString *preset) {
   } else if ([preset isEqualToString:@"max"]) {
     return FLTResolutionPresetMax;
   } else {
-    NSError *error = [NSError errorWithDomain:NSCocoaErrorDomain
-                                         code:NSURLErrorUnknown
-                                     userInfo:@{
-                                       NSLocalizedDescriptionKey : [NSString
-                                           stringWithFormat:@"Unknown resolution preset %@", preset]
-                                     }];
-    @throw error;
+    return FLTResolutionPresetInvalid;
   }
 }