Extend unnecessary_lazy_eval to cover `bool::then` -> `bool::then_some`

diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index cc1530f0ed0da031f8473de9a113f5fe94f5f8c4..36389d798ed573afa8c350cd60e1645bbcae663a 100644 (file)
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -2737,6 +2737,7 @@ fn check_methods<'tcx>(&self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
                     }
                 },
                 ("take", []) => needless_option_take::check(cx, expr, recv),
+                ("then", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "then_some"),
                 ("to_os_string" | "to_owned" | "to_path_buf" | "to_vec", []) => {
                     implicit_clone::check(cx, name, expr, recv);
                 },

diff --git a/clippy_lints/src/methods/unnecessary_lazy_eval.rs b/clippy_lints/src/methods/unnecessary_lazy_eval.rs
index 865f6d0318eb9451c95b0e3bd40b9f667d419c14..a9c641b46068371161a13c6b701a9f1cb7ba218f 100644 (file)
--- a/clippy_lints/src/methods/unnecessary_lazy_eval.rs
+++ b/clippy_lints/src/methods/unnecessary_lazy_eval.rs
@@ -20,8 +20,9 @@ pub(super) fn check<'tcx>(
 ) {
     let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Option);
     let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Result);
+    let is_bool = cx.typeck_results().expr_ty(recv).is_bool();
 
-    if is_option || is_result {
+    if is_option || is_result || is_bool {
         if let hir::ExprKind::Closure { body, .. } = arg.kind {
             let body = cx.tcx.hir().body(body);
             let body_expr = &body.value;
@@ -33,8 +34,10 @@ pub(super) fn check<'tcx>(
             if eager_or_lazy::switch_to_eager_eval(cx, body_expr) {
                 let msg = if is_option {
                     "unnecessary closure used to substitute value for `Option::None`"
-                } else {
+                } else if is_result {
                     "unnecessary closure used to substitute value for `Result::Err`"
+                } else {
+                    "unnecessary closure used with `bool::then`"
                 };
                 let applicability = if body
                     .params

diff --git a/tests/ui/unnecessary_lazy_eval.fixed b/tests/ui/unnecessary_lazy_eval.fixed
index 65fcdc43061bfe8557441050c3cc73c54121ccb5..eed817968832193aa2d7588043480134c3e04d13 100644 (file)
--- a/tests/ui/unnecessary_lazy_eval.fixed
+++ b/tests/ui/unnecessary_lazy_eval.fixed
@@ -30,6 +30,7 @@ fn main() {
     let ext_opt = Some(42);
     let nested_opt = Some(Some(42));
     let nested_tuple_opt = Some(Some((42, 43)));
+    let cond = true;
 
     // Should lint - Option
     let _ = opt.unwrap_or(2);
@@ -42,6 +43,7 @@ fn main() {
     let _ = opt.get_or_insert(2);
     let _ = opt.ok_or(2);
     let _ = nested_tuple_opt.unwrap_or(Some((1, 2)));
+    let _ = cond.then_some(astronomers_pi);
 
     // Cases when unwrap is not called on a simple variable
     let _ = Some(10).unwrap_or(2);

diff --git a/tests/ui/unnecessary_lazy_eval.rs b/tests/ui/unnecessary_lazy_eval.rs
index 206080ed69ada8dd7735ed9b6551cd7b12dc672b..1588db79b38a8c2345a5a623466a705998fedb97 100644 (file)
--- a/tests/ui/unnecessary_lazy_eval.rs
+++ b/tests/ui/unnecessary_lazy_eval.rs
@@ -30,6 +30,7 @@ fn main() {
     let ext_opt = Some(42);
     let nested_opt = Some(Some(42));
     let nested_tuple_opt = Some(Some((42, 43)));
+    let cond = true;
 
     // Should lint - Option
     let _ = opt.unwrap_or_else(|| 2);
@@ -42,6 +43,7 @@ fn main() {
     let _ = opt.get_or_insert_with(|| 2);
     let _ = opt.ok_or_else(|| 2);
     let _ = nested_tuple_opt.unwrap_or_else(|| Some((1, 2)));
+    let _ = cond.then(|| astronomers_pi);
 
     // Cases when unwrap is not called on a simple variable
     let _ = Some(10).unwrap_or_else(|| 2);

diff --git a/tests/ui/unnecessary_lazy_eval.stderr b/tests/ui/unnecessary_lazy_eval.stderr
index 7e4dd7730e71530b79aa78b6f41937a13c90b143..83dc7fd832c38f8a7974f6175fbb3ac91fd8a179 100644 (file)
--- a/tests/ui/unnecessary_lazy_eval.stderr
+++ b/tests/ui/unnecessary_lazy_eval.stderr
@@ -1,5 +1,5 @@
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:35:13
+  --> $DIR/unnecessary_lazy_eval.rs:36:13
    |
 LL |     let _ = opt.unwrap_or_else(|| 2);
    |             ^^^^--------------------
@@ -9,7 +9,7 @@ LL |     let _ = opt.unwrap_or_else(|| 2);
    = note: `-D clippy::unnecessary-lazy-evaluations` implied by `-D warnings`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:36:13
+  --> $DIR/unnecessary_lazy_eval.rs:37:13
    |
 LL |     let _ = opt.unwrap_or_else(|| astronomers_pi);
    |             ^^^^---------------------------------
@@ -17,7 +17,7 @@ LL |     let _ = opt.unwrap_or_else(|| astronomers_pi);
    |                 help: use `unwrap_or(..)` instead: `unwrap_or(astronomers_pi)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:37:13
+  --> $DIR/unnecessary_lazy_eval.rs:38:13
    |
 LL |     let _ = opt.unwrap_or_else(|| ext_str.some_field);
    |             ^^^^-------------------------------------
@@ -25,7 +25,7 @@ LL |     let _ = opt.unwrap_or_else(|| ext_str.some_field);
    |                 help: use `unwrap_or(..)` instead: `unwrap_or(ext_str.some_field)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:39:13
+  --> $DIR/unnecessary_lazy_eval.rs:40:13
    |
 LL |     let _ = opt.and_then(|_| ext_opt);
    |             ^^^^---------------------
@@ -33,7 +33,7 @@ LL |     let _ = opt.and_then(|_| ext_opt);
    |                 help: use `and(..)` instead: `and(ext_opt)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:40:13
+  --> $DIR/unnecessary_lazy_eval.rs:41:13
    |
 LL |     let _ = opt.or_else(|| ext_opt);
    |             ^^^^-------------------
@@ -41,7 +41,7 @@ LL |     let _ = opt.or_else(|| ext_opt);
    |                 help: use `or(..)` instead: `or(ext_opt)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:41:13
+  --> $DIR/unnecessary_lazy_eval.rs:42:13
    |
 LL |     let _ = opt.or_else(|| None);
    |             ^^^^----------------
@@ -49,7 +49,7 @@ LL |     let _ = opt.or_else(|| None);
    |                 help: use `or(..)` instead: `or(None)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:42:13
+  --> $DIR/unnecessary_lazy_eval.rs:43:13
    |
 LL |     let _ = opt.get_or_insert_with(|| 2);
    |             ^^^^------------------------
@@ -57,7 +57,7 @@ LL |     let _ = opt.get_or_insert_with(|| 2);
    |                 help: use `get_or_insert(..)` instead: `get_or_insert(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:43:13
+  --> $DIR/unnecessary_lazy_eval.rs:44:13
    |
 LL |     let _ = opt.ok_or_else(|| 2);
    |             ^^^^----------------
@@ -65,15 +65,23 @@ LL |     let _ = opt.ok_or_else(|| 2);
    |                 help: use `ok_or(..)` instead: `ok_or(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:44:13
+  --> $DIR/unnecessary_lazy_eval.rs:45:13
    |
 LL |     let _ = nested_tuple_opt.unwrap_or_else(|| Some((1, 2)));
    |             ^^^^^^^^^^^^^^^^^-------------------------------
    |                              |
    |                              help: use `unwrap_or(..)` instead: `unwrap_or(Some((1, 2)))`
 
+error: unnecessary closure used with `bool::then`
+  --> $DIR/unnecessary_lazy_eval.rs:46:13
+   |
+LL |     let _ = cond.then(|| astronomers_pi);
+   |             ^^^^^-----------------------
+   |                  |
+   |                  help: use `then_some(..)` instead: `then_some(astronomers_pi)`
+
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:47:13
+  --> $DIR/unnecessary_lazy_eval.rs:49:13
    |
 LL |     let _ = Some(10).unwrap_or_else(|| 2);
    |             ^^^^^^^^^--------------------
@@ -81,7 +89,7 @@ LL |     let _ = Some(10).unwrap_or_else(|| 2);
    |                      help: use `unwrap_or(..)` instead: `unwrap_or(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:48:13
+  --> $DIR/unnecessary_lazy_eval.rs:50:13
    |
 LL |     let _ = Some(10).and_then(|_| ext_opt);
    |             ^^^^^^^^^---------------------
@@ -89,7 +97,7 @@ LL |     let _ = Some(10).and_then(|_| ext_opt);
    |                      help: use `and(..)` instead: `and(ext_opt)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:49:28
+  --> $DIR/unnecessary_lazy_eval.rs:51:28
    |
 LL |     let _: Option<usize> = None.or_else(|| ext_opt);
    |                            ^^^^^-------------------
@@ -97,7 +105,7 @@ LL |     let _: Option<usize> = None.or_else(|| ext_opt);
    |                                 help: use `or(..)` instead: `or(ext_opt)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:50:13
+  --> $DIR/unnecessary_lazy_eval.rs:52:13
    |
 LL |     let _ = None.get_or_insert_with(|| 2);
    |             ^^^^^------------------------
@@ -105,7 +113,7 @@ LL |     let _ = None.get_or_insert_with(|| 2);
    |                  help: use `get_or_insert(..)` instead: `get_or_insert(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:51:35
+  --> $DIR/unnecessary_lazy_eval.rs:53:35
    |
 LL |     let _: Result<usize, usize> = None.ok_or_else(|| 2);
    |                                   ^^^^^----------------
@@ -113,7 +121,7 @@ LL |     let _: Result<usize, usize> = None.ok_or_else(|| 2);
    |                                        help: use `ok_or(..)` instead: `ok_or(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:52:28
+  --> $DIR/unnecessary_lazy_eval.rs:54:28
    |
 LL |     let _: Option<usize> = None.or_else(|| None);
    |                            ^^^^^----------------
@@ -121,7 +129,7 @@ LL |     let _: Option<usize> = None.or_else(|| None);
    |                                 help: use `or(..)` instead: `or(None)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:55:13
+  --> $DIR/unnecessary_lazy_eval.rs:57:13
    |
 LL |     let _ = deep.0.unwrap_or_else(|| 2);
    |             ^^^^^^^--------------------
@@ -129,7 +137,7 @@ LL |     let _ = deep.0.unwrap_or_else(|| 2);
    |                    help: use `unwrap_or(..)` instead: `unwrap_or(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:56:13
+  --> $DIR/unnecessary_lazy_eval.rs:58:13
    |
 LL |     let _ = deep.0.and_then(|_| ext_opt);
    |             ^^^^^^^---------------------
@@ -137,7 +145,7 @@ LL |     let _ = deep.0.and_then(|_| ext_opt);
    |                    help: use `and(..)` instead: `and(ext_opt)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:57:13
+  --> $DIR/unnecessary_lazy_eval.rs:59:13
    |
 LL |     let _ = deep.0.or_else(|| None);
    |             ^^^^^^^----------------
@@ -145,7 +153,7 @@ LL |     let _ = deep.0.or_else(|| None);
    |                    help: use `or(..)` instead: `or(None)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:58:13
+  --> $DIR/unnecessary_lazy_eval.rs:60:13
    |
 LL |     let _ = deep.0.get_or_insert_with(|| 2);
    |             ^^^^^^^------------------------
@@ -153,7 +161,7 @@ LL |     let _ = deep.0.get_or_insert_with(|| 2);
    |                    help: use `get_or_insert(..)` instead: `get_or_insert(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:59:13
+  --> $DIR/unnecessary_lazy_eval.rs:61:13
    |
 LL |     let _ = deep.0.ok_or_else(|| 2);
    |             ^^^^^^^----------------
@@ -161,7 +169,7 @@ LL |     let _ = deep.0.ok_or_else(|| 2);
    |                    help: use `ok_or(..)` instead: `ok_or(2)`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:79:28
+  --> $DIR/unnecessary_lazy_eval.rs:81:28
    |
 LL |     let _: Option<usize> = None.or_else(|| Some(3));
    |                            ^^^^^-------------------
@@ -169,7 +177,7 @@ LL |     let _: Option<usize> = None.or_else(|| Some(3));
    |                                 help: use `or(..)` instead: `or(Some(3))`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:80:13
+  --> $DIR/unnecessary_lazy_eval.rs:82:13
    |
 LL |     let _ = deep.0.or_else(|| Some(3));
    |             ^^^^^^^-------------------
@@ -177,7 +185,7 @@ LL |     let _ = deep.0.or_else(|| Some(3));
    |                    help: use `or(..)` instead: `or(Some(3))`
 
 error: unnecessary closure used to substitute value for `Option::None`
-  --> $DIR/unnecessary_lazy_eval.rs:81:13
+  --> $DIR/unnecessary_lazy_eval.rs:83:13
    |
 LL |     let _ = opt.or_else(|| Some(3));
    |             ^^^^-------------------
@@ -185,7 +193,7 @@ LL |     let _ = opt.or_else(|| Some(3));
    |                 help: use `or(..)` instead: `or(Some(3))`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:87:13
+  --> $DIR/unnecessary_lazy_eval.rs:89:13
    |
 LL |     let _ = res2.unwrap_or_else(|_| 2);
    |             ^^^^^---------------------
@@ -193,7 +201,7 @@ LL |     let _ = res2.unwrap_or_else(|_| 2);
    |                  help: use `unwrap_or(..)` instead: `unwrap_or(2)`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:88:13
+  --> $DIR/unnecessary_lazy_eval.rs:90:13
    |
 LL |     let _ = res2.unwrap_or_else(|_| astronomers_pi);
    |             ^^^^^----------------------------------
@@ -201,7 +209,7 @@ LL |     let _ = res2.unwrap_or_else(|_| astronomers_pi);
    |                  help: use `unwrap_or(..)` instead: `unwrap_or(astronomers_pi)`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:89:13
+  --> $DIR/unnecessary_lazy_eval.rs:91:13
    |
 LL |     let _ = res2.unwrap_or_else(|_| ext_str.some_field);
    |             ^^^^^--------------------------------------
@@ -209,7 +217,7 @@ LL |     let _ = res2.unwrap_or_else(|_| ext_str.some_field);
    |                  help: use `unwrap_or(..)` instead: `unwrap_or(ext_str.some_field)`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:111:35
+  --> $DIR/unnecessary_lazy_eval.rs:113:35
    |
 LL |     let _: Result<usize, usize> = res.and_then(|_| Err(2));
    |                                   ^^^^--------------------
@@ -217,7 +225,7 @@ LL |     let _: Result<usize, usize> = res.and_then(|_| Err(2));
    |                                       help: use `and(..)` instead: `and(Err(2))`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:112:35
+  --> $DIR/unnecessary_lazy_eval.rs:114:35
    |
 LL |     let _: Result<usize, usize> = res.and_then(|_| Err(astronomers_pi));
    |                                   ^^^^---------------------------------
@@ -225,7 +233,7 @@ LL |     let _: Result<usize, usize> = res.and_then(|_| Err(astronomers_pi));
    |                                       help: use `and(..)` instead: `and(Err(astronomers_pi))`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:113:35
+  --> $DIR/unnecessary_lazy_eval.rs:115:35
    |
 LL |     let _: Result<usize, usize> = res.and_then(|_| Err(ext_str.some_field));
    |                                   ^^^^-------------------------------------
@@ -233,7 +241,7 @@ LL |     let _: Result<usize, usize> = res.and_then(|_| Err(ext_str.some_field))
    |                                       help: use `and(..)` instead: `and(Err(ext_str.some_field))`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:115:35
+  --> $DIR/unnecessary_lazy_eval.rs:117:35
    |
 LL |     let _: Result<usize, usize> = res.or_else(|_| Ok(2));
    |                                   ^^^^------------------
@@ -241,7 +249,7 @@ LL |     let _: Result<usize, usize> = res.or_else(|_| Ok(2));
    |                                       help: use `or(..)` instead: `or(Ok(2))`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:116:35
+  --> $DIR/unnecessary_lazy_eval.rs:118:35
    |
 LL |     let _: Result<usize, usize> = res.or_else(|_| Ok(astronomers_pi));
    |                                   ^^^^-------------------------------
@@ -249,7 +257,7 @@ LL |     let _: Result<usize, usize> = res.or_else(|_| Ok(astronomers_pi));
    |                                       help: use `or(..)` instead: `or(Ok(astronomers_pi))`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:117:35
+  --> $DIR/unnecessary_lazy_eval.rs:119:35
    |
 LL |     let _: Result<usize, usize> = res.or_else(|_| Ok(ext_str.some_field));
    |                                   ^^^^-----------------------------------
@@ -257,7 +265,7 @@ LL |     let _: Result<usize, usize> = res.or_else(|_| Ok(ext_str.some_field));
    |                                       help: use `or(..)` instead: `or(Ok(ext_str.some_field))`
 
 error: unnecessary closure used to substitute value for `Result::Err`
-  --> $DIR/unnecessary_lazy_eval.rs:118:35
+  --> $DIR/unnecessary_lazy_eval.rs:120:35
    |
 LL |       let _: Result<usize, usize> = res.
    |  ___________________________________^
@@ -271,5 +279,5 @@ LL | |         or_else(|_| Ok(ext_str.some_field));
    |           |
    |           help: use `or(..)` instead: `or(Ok(ext_str.some_field))`
 
-error: aborting due to 33 previous errors
+error: aborting due to 34 previous errors