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const std = @import("std");
const assert = std.debug.assert;
const mem = std.mem;
const builtin = @import("builtin");
pub fn foo() error!i32 {
const x = try bar();
return x + 1;
}
pub fn bar() error!i32 {
return 13;
}
pub fn baz() error!i32 {
const y = foo() catch 1234;
return y + 1;
}
test "error wrapping" {
assert((baz() catch unreachable) == 15);
}
fn gimmeItBroke() []const u8 {
return @errorName(error.ItBroke);
}
test "@errorName" {
assert(mem.eql(u8, @errorName(error.AnError), "AnError"));
assert(mem.eql(u8, @errorName(error.ALongerErrorName), "ALongerErrorName"));
}
test "error values" {
const a = @errorToInt(error.err1);
const b = @errorToInt(error.err2);
assert(a != b);
}
test "redefinition of error values allowed" {
shouldBeNotEqual(error.AnError, error.SecondError);
}
fn shouldBeNotEqual(a: error, b: error) void {
if (a == b) unreachable;
}
test "error binary operator" {
const a = errBinaryOperatorG(true) catch 3;
const b = errBinaryOperatorG(false) catch 3;
assert(a == 3);
assert(b == 10);
}
fn errBinaryOperatorG(x: bool) error!isize {
return if (x) error.ItBroke else isize(10);
}
test "unwrap simple value from error" {
const i = unwrapSimpleValueFromErrorDo() catch unreachable;
assert(i == 13);
}
fn unwrapSimpleValueFromErrorDo() error!isize {
return 13;
}
test "error return in assignment" {
doErrReturnInAssignment() catch unreachable;
}
fn doErrReturnInAssignment() error!void {
var x: i32 = undefined;
x = try makeANonErr();
}
fn makeANonErr() error!i32 {
return 1;
}
test "error union type " {
testErrorUnionType();
comptime testErrorUnionType();
}
fn testErrorUnionType() void {
const x: error!i32 = 1234;
if (x) |value| assert(value == 1234) else |_| unreachable;
assert(@typeId(@typeOf(x)) == builtin.TypeId.ErrorUnion);
assert(@typeId(@typeOf(x).ErrorSet) == builtin.TypeId.ErrorSet);
assert(@typeOf(x).ErrorSet == error);
}
test "error set type " {
testErrorSetType();
comptime testErrorSetType();
}
const MyErrSet = error{
OutOfMemory,
FileNotFound,
};
fn testErrorSetType() void {
assert(@memberCount(MyErrSet) == 2);
const a: MyErrSet!i32 = 5678;
const b: MyErrSet!i32 = MyErrSet.OutOfMemory;
if (a) |value| assert(value == 5678) else |err| switch (err) {
error.OutOfMemory => unreachable,
error.FileNotFound => unreachable,
}
}
test "explicit error set cast" {
testExplicitErrorSetCast(Set1.A);
comptime testExplicitErrorSetCast(Set1.A);
}
const Set1 = error{
A,
B,
};
const Set2 = error{
A,
C,
};
fn testExplicitErrorSetCast(set1: Set1) void {
var x = @errSetCast(Set2, set1);
var y = @errSetCast(Set1, x);
assert(y == error.A);
}
test "comptime test error for empty error set" {
testComptimeTestErrorEmptySet(1234);
comptime testComptimeTestErrorEmptySet(1234);
}
const EmptyErrorSet = error{};
fn testComptimeTestErrorEmptySet(x: EmptyErrorSet!i32) void {
if (x) |v| assert(v == 1234) else |err| @compileError("bad");
}
test "syntax: optional operator in front of error union operator" {
comptime {
assert(?error!i32 == ?(error!i32));
}
}
test "comptime err to int of error set with only 1 possible value" {
testErrToIntWithOnePossibleValue(error.A, @errorToInt(error.A));
comptime testErrToIntWithOnePossibleValue(error.A, @errorToInt(error.A));
}
fn testErrToIntWithOnePossibleValue(
x: error{A},
comptime value: u32,
) void {
if (@errorToInt(x) != value) {
@compileError("bad");
}
}
test "error union peer type resolution" {
testErrorUnionPeerTypeResolution(1);
comptime testErrorUnionPeerTypeResolution(1);
}
fn testErrorUnionPeerTypeResolution(x: i32) void {
const y = switch (x) {
1 => bar_1(),
2 => baz_1(),
else => quux_1(),
};
}
fn bar_1() error {
return error.A;
}
fn baz_1() !i32 {
return error.B;
}
fn quux_1() !i32 {
return error.C;
}
test "error: fn returning empty error set can be passed as fn returning any error" {
entry();
comptime entry();
}
fn entry() void {
foo2(bar2);
}
fn foo2(f: fn () error!void) void {
const x = f();
}
fn bar2() (error{}!void) {}
test "error: Zero sized error set returned with value payload crash" {
_ = foo3(0);
_ = comptime foo3(0);
}
const Error = error{};
fn foo3(b: usize) Error!usize {
return b;
}
test "error: Infer error set from literals" {
_ = nullLiteral("n") catch |err| handleErrors(err);
_ = floatLiteral("n") catch |err| handleErrors(err);
_ = intLiteral("n") catch |err| handleErrors(err);
_ = comptime nullLiteral("n") catch |err| handleErrors(err);
_ = comptime floatLiteral("n") catch |err| handleErrors(err);
_ = comptime intLiteral("n") catch |err| handleErrors(err);
}
fn handleErrors(err: var) noreturn {
switch (err) {
error.T => {},
}
unreachable;
}
fn nullLiteral(str: []const u8) !?i64 {
if (str[0] == 'n') return null;
return error.T;
}
fn floatLiteral(str: []const u8) !?f64 {
if (str[0] == 'n') return 1.0;
return error.T;
}
fn intLiteral(str: []const u8) !?i64 {
if (str[0] == 'n') return 1;
return error.T;
}
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