library/alloc/tests/fmt.rs

   1 #![deny(warnings)]
   2
   3 use std::cell::RefCell;
   4 use std::fmt::{self, Write};
   5
   6 #[test]
   7 fn test_format() {
   8     let s = fmt::format(format_args!("Hello, {}!", "world"));
   9     assert_eq!(s, "Hello, world!");
  10 }
  11
  12 struct A;
  13 struct B;
  14 struct C;
  15 struct D;
  16
  17 impl fmt::LowerHex for A {
  18     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  19         f.write_str("aloha")
  20     }
  21 }
  22 impl fmt::UpperHex for B {
  23     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  24         f.write_str("adios")
  25     }
  26 }
  27 impl fmt::Display for C {
  28     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  29         f.pad_integral(true, "☃", "123")
  30     }
  31 }
  32 impl fmt::Binary for D {
  33     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  34         f.write_str("aa")?;
  35         f.write_char('☃')?;
  36         f.write_str("bb")
  37     }
  38 }
  39
  40 macro_rules! t {
  41     ($a:expr, $b:expr) => {
  42         assert_eq!($a, $b)
  43     };
  44 }
  45
  46 #[test]
  47 fn test_format_macro_interface() {
  48     // Various edge cases without formats
  49     t!(format!(""), "");
  50     t!(format!("hello"), "hello");
  51     t!(format!("hello {{"), "hello {");
  52
  53     // default formatters should work
  54     t!(format!("{}", 1.0f32), "1");
  55     t!(format!("{}", 1.0f64), "1");
  56     t!(format!("{}", "a"), "a");
  57     t!(format!("{}", "a".to_string()), "a");
  58     t!(format!("{}", false), "false");
  59     t!(format!("{}", 'a'), "a");
  60
  61     // At least exercise all the formats
  62     t!(format!("{}", true), "true");
  63     t!(format!("{}", '☃'), "☃");
  64     t!(format!("{}", 10), "10");
  65     t!(format!("{}", 10_usize), "10");
  66     t!(format!("{:?}", '☃'), "'☃'");
  67     t!(format!("{:?}", 10), "10");
  68     t!(format!("{:?}", 10_usize), "10");
  69     t!(format!("{:?}", "true"), "\"true\"");
  70     t!(format!("{:?}", "foo\nbar"), "\"foo\\nbar\"");
  71     t!(
  72         format!("{:?}", "foo\n\"bar\"\r\n\'baz\'\t\\qux\\"),
  73         r#""foo\n\"bar\"\r\n\'baz\'\t\\qux\\""#
  74     );
  75     t!(format!("{:?}", "foo\0bar\x01baz\u{7f}q\u{75}x"), r#""foo\u{0}bar\u{1}baz\u{7f}qux""#);
  76     t!(format!("{:o}", 10_usize), "12");
  77     t!(format!("{:x}", 10_usize), "a");
  78     t!(format!("{:X}", 10_usize), "A");
  79     t!(format!("{}", "foo"), "foo");
  80     t!(format!("{}", "foo".to_string()), "foo");
  81     if cfg!(target_pointer_width = "32") {
  82         t!(format!("{:#p}", 0x1234 as *const isize), "0x00001234");
  83         t!(format!("{:#p}", 0x1234 as *mut isize), "0x00001234");
  84     } else {
  85         t!(format!("{:#p}", 0x1234 as *const isize), "0x0000000000001234");
  86         t!(format!("{:#p}", 0x1234 as *mut isize), "0x0000000000001234");
  87     }
  88     t!(format!("{:p}", 0x1234 as *const isize), "0x1234");
  89     t!(format!("{:p}", 0x1234 as *mut isize), "0x1234");
  90     t!(format!("{:x}", A), "aloha");
  91     t!(format!("{:X}", B), "adios");
  92     t!(format!("foo {} ☃☃☃☃☃☃", "bar"), "foo bar ☃☃☃☃☃☃");
  93     t!(format!("{1} {0}", 0, 1), "1 0");
  94     t!(format!("{foo} {bar}", foo = 0, bar = 1), "0 1");
  95     t!(format!("{foo} {1} {bar} {0}", 0, 1, foo = 2, bar = 3), "2 1 3 0");
  96     t!(format!("{} {0}", "a"), "a a");
  97     t!(format!("{_foo}", _foo = 6usize), "6");
  98     t!(format!("{foo_bar}", foo_bar = 1), "1");
  99     t!(format!("{}", 5 + 5), "10");
 100     t!(format!("{:#4}", C), "☃123");
 101     t!(format!("{:b}", D), "aa☃bb");
 102
 103     let a: &dyn fmt::Debug = &1;
 104     t!(format!("{:?}", a), "1");
 105
 106     // Formatting strings and their arguments
 107     t!(format!("{}", "a"), "a");
 108     t!(format!("{:4}", "a"), "a   ");
 109     t!(format!("{:4}", "☃"), "☃   ");
 110     t!(format!("{:>4}", "a"), "   a");
 111     t!(format!("{:<4}", "a"), "a   ");
 112     t!(format!("{:^5}", "a"), "  a  ");
 113     t!(format!("{:^5}", "aa"), " aa  ");
 114     t!(format!("{:^4}", "a"), " a  ");
 115     t!(format!("{:^4}", "aa"), " aa ");
 116     t!(format!("{:.4}", "a"), "a");
 117     t!(format!("{:4.4}", "a"), "a   ");
 118     t!(format!("{:4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa");
 119     t!(format!("{:<4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa");
 120     t!(format!("{:>4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa");
 121     t!(format!("{:^4.4}", "aaaaaaaaaaaaaaaaaa"), "aaaa");
 122     t!(format!("{:>10.4}", "aaaaaaaaaaaaaaaaaa"), "      aaaa");
 123     t!(format!("{:2.4}", "aaaaa"), "aaaa");
 124     t!(format!("{:2.4}", "aaaa"), "aaaa");
 125     t!(format!("{:2.4}", "aaa"), "aaa");
 126     t!(format!("{:2.4}", "aa"), "aa");
 127     t!(format!("{:2.4}", "a"), "a ");
 128     t!(format!("{:0>2}", "a"), "0a");
 129     t!(format!("{:.*}", 4, "aaaaaaaaaaaaaaaaaa"), "aaaa");
 130     t!(format!("{:.1$}", "aaaaaaaaaaaaaaaaaa", 4), "aaaa");
 131     t!(format!("{:.a$}", "aaaaaaaaaaaaaaaaaa", a = 4), "aaaa");
 132     t!(format!("{:._a$}", "aaaaaaaaaaaaaaaaaa", _a = 4), "aaaa");
 133     t!(format!("{:1$}", "a", 4), "a   ");
 134     t!(format!("{1:0$}", 4, "a"), "a   ");
 135     t!(format!("{:a$}", "a", a = 4), "a   ");
 136     t!(format!("{:-#}", "a"), "a");
 137     t!(format!("{:+#}", "a"), "a");
 138     t!(format!("{:/^10.8}", "1234567890"), "/12345678/");
 139
 140     // Some float stuff
 141     t!(format!("{:}", 1.0f32), "1");
 142     t!(format!("{:}", 1.0f64), "1");
 143     t!(format!("{:.3}", 1.0f64), "1.000");
 144     t!(format!("{:10.3}", 1.0f64), "     1.000");
 145     t!(format!("{:+10.3}", 1.0f64), "    +1.000");
 146     t!(format!("{:+10.3}", -1.0f64), "    -1.000");
 147
 148     t!(format!("{:e}", 1.2345e6f32), "1.2345e6");
 149     t!(format!("{:e}", 1.2345e6f64), "1.2345e6");
 150     t!(format!("{:E}", 1.2345e6f64), "1.2345E6");
 151     t!(format!("{:.3e}", 1.2345e6f64), "1.234e6");
 152     t!(format!("{:10.3e}", 1.2345e6f64), "   1.234e6");
 153     t!(format!("{:+10.3e}", 1.2345e6f64), "  +1.234e6");
 154     t!(format!("{:+10.3e}", -1.2345e6f64), "  -1.234e6");
 155
 156     // Float edge cases
 157     t!(format!("{}", -0.0), "0");
 158     t!(format!("{:?}", -0.0), "-0.0");
 159     t!(format!("{:?}", 0.0), "0.0");
 160
 161     // sign aware zero padding
 162     t!(format!("{:<3}", 1), "1  ");
 163     t!(format!("{:>3}", 1), "  1");
 164     t!(format!("{:^3}", 1), " 1 ");
 165     t!(format!("{:03}", 1), "001");
 166     t!(format!("{:<03}", 1), "001");
 167     t!(format!("{:>03}", 1), "001");
 168     t!(format!("{:^03}", 1), "001");
 169     t!(format!("{:+03}", 1), "+01");
 170     t!(format!("{:<+03}", 1), "+01");
 171     t!(format!("{:>+03}", 1), "+01");
 172     t!(format!("{:^+03}", 1), "+01");
 173     t!(format!("{:#05x}", 1), "0x001");
 174     t!(format!("{:<#05x}", 1), "0x001");
 175     t!(format!("{:>#05x}", 1), "0x001");
 176     t!(format!("{:^#05x}", 1), "0x001");
 177     t!(format!("{:05}", 1.2), "001.2");
 178     t!(format!("{:<05}", 1.2), "001.2");
 179     t!(format!("{:>05}", 1.2), "001.2");
 180     t!(format!("{:^05}", 1.2), "001.2");
 181     t!(format!("{:05}", -1.2), "-01.2");
 182     t!(format!("{:<05}", -1.2), "-01.2");
 183     t!(format!("{:>05}", -1.2), "-01.2");
 184     t!(format!("{:^05}", -1.2), "-01.2");
 185     t!(format!("{:+05}", 1.2), "+01.2");
 186     t!(format!("{:<+05}", 1.2), "+01.2");
 187     t!(format!("{:>+05}", 1.2), "+01.2");
 188     t!(format!("{:^+05}", 1.2), "+01.2");
 189
 190     // Ergonomic format_args!
 191     t!(format!("{0:x} {0:X}", 15), "f F");
 192     t!(format!("{0:x} {0:X} {}", 15), "f F 15");
 193     t!(format!("{:x}{0:X}{a:x}{:X}{1:x}{a:X}", 13, 14, a = 15), "dDfEeF");
 194     t!(format!("{a:x} {a:X}", a = 15), "f F");
 195
 196     // And its edge cases
 197     t!(
 198         format!(
 199             "{a:.0$} {b:.0$} {0:.0$}\n{a:.c$} {b:.c$} {c:.c$}",
 200             4,
 201             a = "abcdefg",
 202             b = "hijklmn",
 203             c = 3
 204         ),
 205         "abcd hijk 4\nabc hij 3"
 206     );
 207     t!(format!("{a:.*} {0} {:.*}", 4, 3, "efgh", a = "abcdef"), "abcd 4 efg");
 208     t!(format!("{:.a$} {a} {a:#x}", "aaaaaa", a = 2), "aa 2 0x2");
 209
 210     // Test that pointers don't get truncated.
 211     {
 212         let val = usize::MAX;
 213         let exp = format!("{:#x}", val);
 214         t!(format!("{:p}", val as *const isize), exp);
 215     }
 216
 217     // Escaping
 218     t!(format!("{{"), "{");
 219     t!(format!("}}"), "}");
 220
 221     // make sure that format! doesn't move out of local variables
 222     let a = Box::new(3);
 223     format!("{}", a);
 224     format!("{}", a);
 225
 226     // make sure that format! doesn't cause spurious unused-unsafe warnings when
 227     // it's inside of an outer unsafe block
 228     unsafe {
 229         let a: isize = ::std::mem::transmute(3_usize);
 230         format!("{}", a);
 231     }
 232
 233     // test that trailing commas are acceptable
 234     format!("{}", "test",);
 235     format!("{foo}", foo = "test",);
 236 }
 237
 238 // Basic test to make sure that we can invoke the `write!` macro with an
 239 // fmt::Write instance.
 240 #[test]
 241 fn test_write() {
 242     let mut buf = String::new();
 243     let _ = write!(&mut buf, "{}", 3);
 244     {
 245         let w = &mut buf;
 246         let _ = write!(w, "{foo}", foo = 4);
 247         let _ = write!(w, "{}", "hello");
 248         let _ = writeln!(w, "{}", "line");
 249         let _ = writeln!(w, "{foo}", foo = "bar");
 250         let _ = w.write_char('☃');
 251         let _ = w.write_str("str");
 252     }
 253
 254     t!(buf, "34helloline\nbar\n☃str");
 255 }
 256
 257 // Just make sure that the macros are defined, there's not really a lot that we
 258 // can do with them just yet (to test the output)
 259 #[test]
 260 fn test_print() {
 261     print!("hi");
 262     print!("{:?}", vec![0u8]);
 263     println!("hello");
 264     println!("this is a {}", "test");
 265     println!("{foo}", foo = "bar");
 266 }
 267
 268 // Just make sure that the macros are defined, there's not really a lot that we
 269 // can do with them just yet (to test the output)
 270 #[test]
 271 fn test_format_args() {
 272     let mut buf = String::new();
 273     {
 274         let w = &mut buf;
 275         let _ = write!(w, "{}", format_args!("{}", 1));
 276         let _ = write!(w, "{}", format_args!("test"));
 277         let _ = write!(w, "{}", format_args!("{test}", test = 3));
 278     }
 279     let s = buf;
 280     t!(s, "1test3");
 281
 282     let s = fmt::format(format_args!("hello {}", "world"));
 283     t!(s, "hello world");
 284     let s = format!("{}: {}", "args were", format_args!("hello {}", "world"));
 285     t!(s, "args were: hello world");
 286 }
 287
 288 #[test]
 289 fn test_order() {
 290     // Make sure format!() arguments are always evaluated in a left-to-right
 291     // ordering
 292     fn foo() -> isize {
 293         static mut FOO: isize = 0;
 294         unsafe {
 295             FOO += 1;
 296             FOO
 297         }
 298     }
 299     assert_eq!(
 300         format!("{} {} {a} {b} {} {c}", foo(), foo(), foo(), a = foo(), b = foo(), c = foo()),
 301         "1 2 4 5 3 6".to_string()
 302     );
 303 }
 304
 305 #[test]
 306 fn test_once() {
 307     // Make sure each argument are evaluated only once even though it may be
 308     // formatted multiple times
 309     fn foo() -> isize {
 310         static mut FOO: isize = 0;
 311         unsafe {
 312             FOO += 1;
 313             FOO
 314         }
 315     }
 316     assert_eq!(format!("{0} {0} {0} {a} {a} {a}", foo(), a = foo()), "1 1 1 2 2 2".to_string());
 317 }
 318
 319 #[test]
 320 fn test_refcell() {
 321     let refcell = RefCell::new(5);
 322     assert_eq!(format!("{:?}", refcell), "RefCell { value: 5 }");
 323     let borrow = refcell.borrow_mut();
 324     assert_eq!(format!("{:?}", refcell), "RefCell { value: <borrowed> }");
 325     drop(borrow);
 326     assert_eq!(format!("{:?}", refcell), "RefCell { value: 5 }");
 327 }