1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
use core::fmt;
use core::panic::{RefUnwindSafe, UnwindSafe};
use super::{NSCopying, NSDictionary, NSObject, NSString};
use crate::ffi::NSInteger;
use crate::rc::{Id, Shared};
use crate::{extern_class, extern_methods, msg_send_id, ClassType};
extern_class!(
/// Information about an error condition including a domain, a
/// domain-specific error code, and application-specific information.
///
/// See also Apple's [documentation on error handling][err], and their
/// NSError [API reference][api].
///
/// [err]: https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ErrorHandlingCocoa/ErrorHandling/ErrorHandling.html#//apple_ref/doc/uid/TP40001806-CH201-SW1
/// [api]: https://developer.apple.com/documentation/foundation/nserror?language=objc
#[derive(PartialEq, Eq, Hash)]
pub struct NSError;
unsafe impl ClassType for NSError {
type Super = NSObject;
}
);
// SAFETY: Error objects are immutable data containers.
unsafe impl Sync for NSError {}
unsafe impl Send for NSError {}
impl UnwindSafe for NSError {}
impl RefUnwindSafe for NSError {}
pub type NSErrorUserInfoKey = NSString;
pub type NSErrorDomain = NSString;
extern_methods!(
/// Creation methods.
unsafe impl NSError {
/// Construct a new [`NSError`] with the given code in the given domain.
pub fn new(code: NSInteger, domain: &NSString) -> Id<Self, Shared> {
unsafe { Self::with_user_info(code, domain, None) }
}
// TODO: Figure out safety of `user_info` dict!
unsafe fn with_user_info(
code: NSInteger,
domain: &NSString,
user_info: Option<&NSDictionary<NSErrorUserInfoKey, NSObject>>,
) -> Id<Self, Shared> {
// SAFETY: `domain` and `user_info` are copied to the error object, so
// even if the `&NSString` came from a `&mut NSMutableString`, we're
// still good!
unsafe {
msg_send_id![
msg_send_id![Self::class(), alloc],
initWithDomain: domain,
code: code,
userInfo: user_info,
]
}
}
}
/// Accessor methods.
unsafe impl NSError {
pub fn domain(&self) -> Id<NSString, Shared> {
unsafe { msg_send_id![self, domain] }
}
#[sel(code)]
pub fn code(&self) -> NSInteger;
pub fn user_info(&self) -> Option<Id<NSDictionary<NSErrorUserInfoKey, NSObject>, Shared>> {
unsafe { msg_send_id![self, userInfo] }
}
pub fn localized_description(&self) -> Id<NSString, Shared> {
// TODO: For some reason this leaks a lot?
let obj: Option<_> = unsafe { msg_send_id![self, localizedDescription] };
obj.expect(
"unexpected NULL localized description; a default should have been generated!",
)
}
// TODO: localizedRecoveryOptions
// TODO: localizedRecoverySuggestion
// TODO: localizedFailureReason
// TODO: helpAnchor
// TODO: +setUserInfoValueProviderForDomain:provider:
// TODO: +userInfoValueProviderForDomain:
// TODO: recoveryAttempter
// TODO: attemptRecoveryFromError:...
// TODO: Figure out if this is a good design, or if we should do something
// differently (like a Rusty name for the function, or putting a bunch of
// statics in a module instead)?
#[allow(non_snake_case)]
pub fn NSLocalizedDescriptionKey() -> &'static NSErrorUserInfoKey {
extern "C" {
#[link_name = "NSLocalizedDescriptionKey"]
static VALUE: &'static NSErrorUserInfoKey;
}
unsafe { VALUE }
}
// TODO: Other NSErrorUserInfoKey values
// TODO: NSErrorDomain values
}
);
impl fmt::Debug for NSError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("NSError")
.field("domain", &self.domain())
.field("code", &self.code())
.field("user_info", &self.user_info())
.finish()
}
}
impl fmt::Display for NSError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.localized_description())
}
}
impl std::error::Error for NSError {}
unsafe impl NSCopying for NSError {
type Ownership = Shared;
type Output = Self;
}
#[cfg(test)]
mod tests {
use super::*;
use alloc::format;
use crate::ns_string;
#[test]
fn custom_domain() {
let error = NSError::new(42, ns_string!("MyDomain"));
assert_eq!(error.code(), 42);
assert_eq!(&*error.domain(), ns_string!("MyDomain"));
let expected = if cfg!(feature = "apple") {
"The operation couldn’t be completed. (MyDomain error 42.)"
} else {
"MyDomain 42"
};
assert_eq!(format!("{}", error), expected);
}
#[test]
fn basic() {
let error = NSError::new(-999, ns_string!("NSURLErrorDomain"));
let expected = if cfg!(feature = "apple") {
"The operation couldn’t be completed. (NSURLErrorDomain error -999.)"
} else {
"NSURLErrorDomain -999"
};
assert_eq!(format!("{}", error), expected);
}
}