src/test/ui/fmt/ifmt-bad-arg.rs

   1 fn main() {
   2     // bad arguments to the format! call
   3
   4     // bad number of arguments, see #44954 (originally #15780)
   5
   6     format!("{}");
   7     //~^ ERROR: 1 positional argument in format string, but no arguments were given
   8
   9     format!("{1}", 1);
  10     //~^ ERROR: invalid reference to positional argument 1 (there is 1 argument)
  11     //~^^ ERROR: argument never used
  12
  13     format!("{} {}");
  14     //~^ ERROR: 2 positional arguments in format string, but no arguments were given
  15
  16     format!("{0} {1}", 1);
  17     //~^ ERROR: invalid reference to positional argument 1 (there is 1 argument)
  18
  19     format!("{0} {1} {2}", 1, 2);
  20     //~^ ERROR: invalid reference to positional argument 2 (there are 2 arguments)
  21
  22     format!("{} {value} {} {}", 1, value=2);
  23     //~^ ERROR: invalid reference to positional argument 2 (there are 2 arguments)
  24     format!("{name} {value} {} {} {} {} {} {}", 0, name=1, value=2);
  25     //~^ ERROR: invalid reference to positional arguments 3, 4 and 5 (there are 3 arguments)
  26
  27     format!("{} {foo} {} {bar} {}", 1, 2, 3);
  28     //~^ ERROR: cannot find value `foo` in this scope
  29     //~^^ ERROR: cannot find value `bar` in this scope
  30
  31     format!("{foo}");                //~ ERROR: cannot find value `foo` in this scope
  32     format!("", 1, 2);               //~ ERROR: multiple unused formatting arguments
  33     format!("{}", 1, 2);             //~ ERROR: argument never used
  34     format!("{1}", 1, 2);            //~ ERROR: argument never used
  35     format!("{}", 1, foo=2);         //~ ERROR: named argument never used
  36     format!("{foo}", 1, foo=2);      //~ ERROR: argument never used
  37     format!("", foo=2);              //~ ERROR: named argument never used
  38     format!("{} {}", 1, 2, foo=1, bar=2);  //~ ERROR: multiple unused formatting arguments
  39
  40     format!("{foo}", foo=1, foo=2);  //~ ERROR: duplicate argument
  41     format!("{foo} {} {}", foo=1, 2);   //~ ERROR: positional arguments cannot follow
  42
  43     // bad named arguments, #35082
  44
  45     format!("{valuea} {valueb}", valuea=5, valuec=7);
  46     //~^ ERROR cannot find value `valueb` in this scope
  47     //~^^ ERROR named argument never used
  48
  49     // bad syntax of the format string
  50
  51     format!("{"); //~ ERROR: expected `'}'` but string was terminated
  52
  53     format!("foo } bar"); //~ ERROR: unmatched `}` found
  54     format!("foo }"); //~ ERROR: unmatched `}` found
  55
  56     format!("foo %s baz", "bar"); //~ ERROR: argument never used
  57
  58     format!(r##"
  59
  60         {foo}
  61
  62     "##);
  63     //~^^^ ERROR: cannot find value `foo` in this scope
  64
  65     // bad syntax in format string with multiple newlines, #53836
  66     format!("first number: {}
  67 second number: {}
  68 third number: {}
  69 fourth number: {}
  70 fifth number: {}
  71 sixth number: {}
  72 seventh number: {}
  73 eighth number: {}
  74 ninth number: {
  75 tenth number: {}",
  76         1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
  77     //~^^ ERROR: invalid format string
  78     println!("{} {:.*} {}", 1, 3.2, 4);
  79     //~^ ERROR 4 positional arguments in format string, but there are 3 arguments
  80     //~| ERROR mismatched types
  81     println!("{} {:07$.*} {}", 1, 3.2, 4);
  82     //~^ ERROR 4 positional arguments in format string, but there are 3 arguments
  83     //~| ERROR mismatched types
  84     println!("{} {:07$} {}", 1, 3.2, 4);
  85     //~^ ERROR invalid reference to positional argument 7 (there are 3 arguments)
  86     println!("{:foo}", 1); //~ ERROR unknown format trait `foo`
  87     println!("{5} {:4$} {6:7$}", 1);
  88     //~^ ERROR invalid reference to positional arguments 4, 5, 6 and 7 (there is 1 argument)
  89
  90     // We used to ICE here because we tried to unconditionally access the first argument, which
  91     // doesn't exist.
  92     println!("{:.*}");
  93     //~^ ERROR 2 positional arguments in format string, but no arguments were given
  94 }