src/tools/clippy/tests/ui/needless_question_mark.rs

   1 // run-rustfix
   2
   3 #![warn(clippy::needless_question_mark)]
   4 #![allow(
   5     clippy::needless_return,
   6     clippy::unnecessary_unwrap,
   7     clippy::upper_case_acronyms,
   8     dead_code,
   9     unused_must_use
  10 )]
  11 #![feature(custom_inner_attributes)]
  12
  13 struct TO {
  14     magic: Option<usize>,
  15 }
  16
  17 struct TR {
  18     magic: Result<usize, bool>,
  19 }
  20
  21 fn simple_option_bad1(to: TO) -> Option<usize> {
  22     // return as a statement
  23     return Some(to.magic?);
  24 }
  25
  26 // formatting will add a semi-colon, which would make
  27 // this identical to the test case above
  28 #[rustfmt::skip]
  29 fn simple_option_bad2(to: TO) -> Option<usize> {
  30     // return as an expression
  31     return Some(to.magic?)
  32 }
  33
  34 fn simple_option_bad3(to: TO) -> Option<usize> {
  35     // block value "return"
  36     Some(to.magic?)
  37 }
  38
  39 fn simple_option_bad4(to: Option<TO>) -> Option<usize> {
  40     // single line closure
  41     to.and_then(|t| Some(t.magic?))
  42 }
  43
  44 // formatting this will remove the block brackets, making
  45 // this test identical to the one above
  46 #[rustfmt::skip]
  47 fn simple_option_bad5(to: Option<TO>) -> Option<usize> {
  48     // closure with body
  49     to.and_then(|t| {
  50         Some(t.magic?)
  51     })
  52 }
  53
  54 fn simple_result_bad1(tr: TR) -> Result<usize, bool> {
  55     return Ok(tr.magic?);
  56 }
  57
  58 // formatting will add a semi-colon, which would make
  59 // this identical to the test case above
  60 #[rustfmt::skip]
  61 fn simple_result_bad2(tr: TR) -> Result<usize, bool> {
  62     return Ok(tr.magic?)
  63 }
  64
  65 fn simple_result_bad3(tr: TR) -> Result<usize, bool> {
  66     Ok(tr.magic?)
  67 }
  68
  69 fn simple_result_bad4(tr: Result<TR, bool>) -> Result<usize, bool> {
  70     tr.and_then(|t| Ok(t.magic?))
  71 }
  72
  73 // formatting this will remove the block brackets, making
  74 // this test identical to the one above
  75 #[rustfmt::skip]
  76 fn simple_result_bad5(tr: Result<TR, bool>) -> Result<usize, bool> {
  77     tr.and_then(|t| {
  78         Ok(t.magic?)
  79     })
  80 }
  81
  82 fn also_bad(tr: Result<TR, bool>) -> Result<usize, bool> {
  83     if tr.is_ok() {
  84         let t = tr.unwrap();
  85         return Ok(t.magic?);
  86     }
  87     Err(false)
  88 }
  89
  90 fn false_positive_test<U, T>(x: Result<(), U>) -> Result<(), T>
  91 where
  92     T: From<U>,
  93 {
  94     Ok(x?)
  95 }
  96
  97 fn main() {}
  98
  99 mod question_mark_none {
 100     #![clippy::msrv = "1.12.0"]
 101     fn needless_question_mark_option() -> Option<usize> {
 102         struct TO {
 103             magic: Option<usize>,
 104         }
 105         let to = TO { magic: None };
 106         Some(to.magic?) // should not be triggered
 107     }
 108
 109     fn needless_question_mark_result() -> Result<usize, bool> {
 110         struct TO {
 111             magic: Result<usize, bool>,
 112         }
 113         let to = TO { magic: Ok(1_usize) };
 114         Ok(to.magic?) // should not be triggered
 115     }
 116
 117     fn main() {
 118         needless_question_mark_option();
 119         needless_question_mark_result();
 120     }
 121 }
 122
 123 mod question_mark_result {
 124     #![clippy::msrv = "1.21.0"]
 125     fn needless_question_mark_option() -> Option<usize> {
 126         struct TO {
 127             magic: Option<usize>,
 128         }
 129         let to = TO { magic: None };
 130         Some(to.magic?) // should not be triggered
 131     }
 132
 133     fn needless_question_mark_result() -> Result<usize, bool> {
 134         struct TO {
 135             magic: Result<usize, bool>,
 136         }
 137         let to = TO { magic: Ok(1_usize) };
 138         Ok(to.magic?) // should be triggered
 139     }
 140
 141     fn main() {
 142         needless_question_mark_option();
 143         needless_question_mark_result();
 144     }
 145 }
 146
 147 mod question_mark_both {
 148     #![clippy::msrv = "1.22.0"]
 149     fn needless_question_mark_option() -> Option<usize> {
 150         struct TO {
 151             magic: Option<usize>,
 152         }
 153         let to = TO { magic: None };
 154         Some(to.magic?) // should be triggered
 155     }
 156
 157     fn needless_question_mark_result() -> Result<usize, bool> {
 158         struct TO {
 159             magic: Result<usize, bool>,
 160         }
 161         let to = TO { magic: Ok(1_usize) };
 162         Ok(to.magic?) // should be triggered
 163     }
 164
 165     fn main() {
 166         needless_question_mark_option();
 167         needless_question_mark_result();
 168     }
 169 }