#![deny(warnings)] // FIXME(static_mut_refs): Do not allow `static_mut_refs` lint #![allow(static_mut_refs)] use std::cell::RefCell; use std::fmt::{self, Write}; use std::ptr; #[test] fn test_format() { let s = fmt::format(format_args!("Hello, {}!", "world")); assert_eq!(s, "Hello, world!"); } struct A; struct B; struct C; struct D; impl fmt::LowerHex for A { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_str("aloha") } } impl fmt::UpperHex for B { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_str("adios") } } impl fmt::Display for C { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.pad_integral(true, "☃", "123") } } impl fmt::Binary for D { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_str("aa")?; f.write_char('☃')?; f.write_str("bb") } } macro_rules! t { ($a:expr, $b:expr) => { assert_eq!($a, $b) }; } #[test] fn test_format_macro_interface() { // Various edge cases without formats t!(format!(""), ""); t!(format!("hello"), "hello"); t!(format!("hello {{"), "hello {"); // default formatters should work t!(format!("{}", 1.0f32), "1"); t!(format!("{}", 1.0f64), "1"); t!(format!("{}", "a"), "a"); t!(format!("{}", "a".to_string()), "a"); t!(format!("{}", false), "false"); t!(format!("{}", 'a'), "a"); // At least exercise all the formats t!(format!("{}", true), "true"); t!(format!("{}", '☃'), "☃"); t!(format!("{}", 10), "10"); t!(format!("{}", 10_usize), "10"); t!(format!("{:?}", '☃'), "'☃'"); t!(format!("{:?}", 10), "10"); t!(format!("{:?}", 10_usize), "10"); t!(format!("{:?}", "true"), "\"true\""); t!(format!("{:?}", "foo\nbar"), "\"foo\\nbar\""); t!(format!("{:?}", "foo\n\"bar\"\r\n\'baz\'\t\\qux\\"), r#""foo\n\"bar\"\r\n'baz'\t\\qux\\""#); t!(format!("{:?}", "foo\0bar\x01baz\u{7f}q\u{75}x"), r#""foo\0bar\u{1}baz\u{7f}qux""#); t!(format!("{:o}", 10_usize), "12"); t!(format!("{:x}", 10_usize), "a"); t!(format!("{:X}", 10_usize), "A"); t!(format!("{}", "foo"), "foo"); t!(format!("{}", "foo".to_string()), "foo"); if cfg!(target_pointer_width = "32") { t!(format!("{:#p}", ptr::without_provenance::(0x1234)), "0x00001234"); t!(format!("{:#p}", ptr::without_provenance_mut::(0x1234)), "0x00001234"); } else { t!(format!("{:#p}", ptr::without_provenance::(0x1234)), "0x0000000000001234"); t!(format!("{:#p}", ptr::without_provenance_mut::(0x1234)), "0x0000000000001234"); } t!(format!("{:p}", ptr::without_provenance::(0x1234)), "0x1234"); t!(format!("{:p}", ptr::without_provenance_mut::(0x1234)), "0x1234"); t!(format!("{A:x}"), "aloha"); t!(format!("{B:X}"), "adios"); t!(format!("foo {} ☃☃☃☃☃☃", "bar"), "foo bar ☃☃☃☃☃☃"); t!(format!("{1} {0}", 0, 1), "1 0"); t!(format!("{foo} {bar}", foo = 0, bar = 1), "0 1"); t!(format!("{foo} {1} {bar} {0}", 0, 1, foo = 2, bar = 3), "2 1 3 0"); t!(format!("{} {0}", "a"), "a a"); t!(format!("{_foo}", _foo = 6usize), "6"); t!(format!("{foo_bar}", foo_bar = 1), "1"); t!(format!("{}", 5 + 5), "10"); t!(format!("{C:#4}"), "☃123"); t!(format!("{D:b}"), "aa☃bb"); let a: &dyn fmt::Debug = &1; t!(format!("{a:?}"), "1"); // Formatting strings and their arguments t!(format!("{}", "a"), "a"); t!(format!("{:4}", "a"), "a "); t!(format!("{:4}", "☃"), "☃ "); t!(format!("{:>4}", "a"), " a"); t!(format!("{:<4}", "a"), "a "); t!(format!("{:^5}", "a"), " a "); t!(format!("{:^5}", "aa"), " aa "); t!(format!("{:^4}", "a"), " a "); t!(format!("{:^4}", "aa"), " aa "); t!(format!("{:.4}", "a"), "a"); t!(format!("{:4.4}", "a"), "a "); t!(format!("{:4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa"); t!(format!("{:<4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa"); t!(format!("{:>4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa"); t!(format!("{:^4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa"); t!(format!("{:>10.4}", "aaaaaaaaaaaaaaaaaa"), " aaaa"); t!(format!("{:2.4}", "aaaaa"), "aaaa"); t!(format!("{:2.4}", "aaaa"), "aaaa"); t!(format!("{:2.4}", "aaa"), "aaa"); t!(format!("{:2.4}", "aa"), "aa"); t!(format!("{:2.4}", "a"), "a "); t!(format!("{:0>2}", "a"), "0a"); t!(format!("{:.*}", 4, "aaaaaaaaaaaaaaaaaa"), "aaaa"); t!(format!("{:.1$}", "aaaaaaaaaaaaaaaaaa", 4), "aaaa"); t!(format!("{:.a$}", "aaaaaaaaaaaaaaaaaa", a = 4), "aaaa"); t!(format!("{:._a$}", "aaaaaaaaaaaaaaaaaa", _a = 4), "aaaa"); t!(format!("{:1$}", "a", 4), "a "); t!(format!("{1:0$}", 4, "a"), "a "); t!(format!("{:a$}", "a", a = 4), "a "); t!(format!("{:-#}", "a"), "a"); t!(format!("{:+#}", "a"), "a"); t!(format!("{:/^10.8}", "1234567890"), "/12345678/"); // Some float stuff t!(format!("{:}", 1.0f32), "1"); t!(format!("{:}", 1.0f64), "1"); t!(format!("{:.3}", 1.0f64), "1.000"); t!(format!("{:10.3}", 1.0f64), " 1.000"); t!(format!("{:+10.3}", 1.0f64), " +1.000"); t!(format!("{:+10.3}", -1.0f64), " -1.000"); t!(format!("{:e}", 1.2345e6f32), "1.2345e6"); t!(format!("{:e}", 1.2345e6f64), "1.2345e6"); t!(format!("{:E}", 1.2345e6f64), "1.2345E6"); t!(format!("{:.3e}", 1.2345e6f64), "1.234e6"); t!(format!("{:10.3e}", 1.2345e6f64), " 1.234e6"); t!(format!("{:+10.3e}", 1.2345e6f64), " +1.234e6"); t!(format!("{:+10.3e}", -1.2345e6f64), " -1.234e6"); // Float edge cases t!(format!("{}", -0.0), "-0"); t!(format!("{:?}", 0.0), "0.0"); // sign aware zero padding t!(format!("{:<3}", 1), "1 "); t!(format!("{:>3}", 1), " 1"); t!(format!("{:^3}", 1), " 1 "); t!(format!("{:03}", 1), "001"); t!(format!("{:<03}", 1), "001"); t!(format!("{:>03}", 1), "001"); t!(format!("{:^03}", 1), "001"); t!(format!("{:+03}", 1), "+01"); t!(format!("{:<+03}", 1), "+01"); t!(format!("{:>+03}", 1), "+01"); t!(format!("{:^+03}", 1), "+01"); t!(format!("{:#05x}", 1), "0x001"); t!(format!("{:<#05x}", 1), "0x001"); t!(format!("{:>#05x}", 1), "0x001"); t!(format!("{:^#05x}", 1), "0x001"); t!(format!("{:05}", 1.2), "001.2"); t!(format!("{:<05}", 1.2), "001.2"); t!(format!("{:>05}", 1.2), "001.2"); t!(format!("{:^05}", 1.2), "001.2"); t!(format!("{:05}", -1.2), "-01.2"); t!(format!("{:<05}", -1.2), "-01.2"); t!(format!("{:>05}", -1.2), "-01.2"); t!(format!("{:^05}", -1.2), "-01.2"); t!(format!("{:+05}", 1.2), "+01.2"); t!(format!("{:<+05}", 1.2), "+01.2"); t!(format!("{:>+05}", 1.2), "+01.2"); t!(format!("{:^+05}", 1.2), "+01.2"); // Ergonomic format_args! t!(format!("{0:x} {0:X}", 15), "f F"); t!(format!("{0:x} {0:X} {}", 15), "f F 15"); t!(format!("{:x}{0:X}{a:x}{:X}{1:x}{a:X}", 13, 14, a = 15), "dDfEeF"); t!(format!("{a:x} {a:X}", a = 15), "f F"); // And its edge cases t!( format!( "{a:.0$} {b:.0$} {0:.0$}\n{a:.c$} {b:.c$} {c:.c$}", 4, a = "abcdefg", b = "hijklmn", c = 3 ), "abcd hijk 4\nabc hij 3" ); t!(format!("{a:.*} {0} {:.*}", 4, 3, "efgh", a = "abcdef"), "abcd 4 efg"); t!(format!("{:.a$} {a} {a:#x}", "aaaaaa", a = 2), "aa 2 0x2"); // Test that pointers don't get truncated. { let val = usize::MAX; let exp = format!("{val:#x}"); t!(format!("{:p}", std::ptr::without_provenance::(val)), exp); } // Escaping t!(format!("{{"), "{"); t!(format!("}}"), "}"); // make sure that format! doesn't move out of local variables let a = Box::new(3); let _ = format!("{a}"); let _ = format!("{a}"); // make sure that format! doesn't cause spurious unused-unsafe warnings when // it's inside of an outer unsafe block unsafe { let a: isize = ::std::mem::transmute(3_usize); let _ = format!("{a}"); } // test that trailing commas are acceptable let _ = format!("{}", "test",); let _ = format!("{foo}", foo = "test",); } // Basic test to make sure that we can invoke the `write!` macro with an // fmt::Write instance. #[test] fn test_write() { let mut buf = String::new(); let _ = write!(&mut buf, "{}", 3); { let w = &mut buf; let _ = write!(w, "{foo}", foo = 4); let _ = write!(w, "{}", "hello"); let _ = writeln!(w, "{}", "line"); let _ = writeln!(w, "{foo}", foo = "bar"); let _ = w.write_char('☃'); let _ = w.write_str("str"); } t!(buf, "34helloline\nbar\n☃str"); } // Just make sure that the macros are defined, there's not really a lot that we // can do with them just yet (to test the output) #[test] fn test_print() { print!("hi"); print!("{:?}", vec![0u8]); println!("hello"); println!("this is a {}", "test"); println!("{foo}", foo = "bar"); } // Just make sure that the macros are defined, there's not really a lot that we // can do with them just yet (to test the output) #[test] fn test_format_args() { let mut buf = String::new(); { let w = &mut buf; let _ = write!(w, "{}", format_args!("{}", 1)); let _ = write!(w, "{}", format_args!("test")); let _ = write!(w, "{}", format_args!("{test}", test = 3)); } let s = buf; t!(s, "1test3"); let s = fmt::format(format_args!("hello {}", "world")); t!(s, "hello world"); let s = format!("{}: {}", "args were", format_args!("hello {}", "world")); t!(s, "args were: hello world"); } #[test] fn test_order() { // Make sure format!() arguments are always evaluated in a left-to-right // ordering fn foo() -> isize { static mut FOO: isize = 0; unsafe { FOO += 1; FOO } } assert_eq!( format!("{} {} {a} {b} {} {c}", foo(), foo(), foo(), a = foo(), b = foo(), c = foo()), "1 2 4 5 3 6".to_string() ); } #[test] fn test_once() { // Make sure each argument are evaluated only once even though it may be // formatted multiple times fn foo() -> isize { static mut FOO: isize = 0; unsafe { FOO += 1; FOO } } assert_eq!(format!("{0} {0} {0} {a} {a} {a}", foo(), a = foo()), "1 1 1 2 2 2".to_string()); } #[test] fn test_refcell() { let refcell = RefCell::new(5); assert_eq!(format!("{refcell:?}"), "RefCell { value: 5 }"); let borrow = refcell.borrow_mut(); assert_eq!(format!("{refcell:?}"), "RefCell { value: }"); drop(borrow); assert_eq!(format!("{refcell:?}"), "RefCell { value: 5 }"); }