Recognize unwrap_or_else method

Author: pksunkara

CHANGELOG.md

@@ -5248,6 +5248,7 @@ Released 2018-09-13
 [`unnecessary_fold`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold
 [`unnecessary_join`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_join
 [`unnecessary_lazy_evaluations`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations
+[`unnecessary_literal_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
 [`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed
 [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation
 [`unnecessary_owned_empty_strings`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_owned_empty_strings

clippy_lints/src/methods/mod.rs

@@ -3893,13 +3893,16 @@ impl Methods {
                 ("unwrap_or_default", []) => {
                     unnecessary_literal_unwrap::check(cx, expr, recv, name);
                 }
-                ("unwrap_or_else", [u_arg]) => match method_call(recv) {
-                    Some(("map", recv, [map_arg], _, _))
-                        if map_unwrap_or::check(cx, expr, recv, map_arg, u_arg, &self.msrv) => {},
-                    _ => {
-                        unwrap_or_else_default::check(cx, expr, recv, u_arg);
-                        unnecessary_lazy_eval::check(cx, expr, recv, u_arg, "unwrap_or");
-                    },
+                ("unwrap_or_else", [u_arg]) => {
+                    match method_call(recv) {
+                        Some(("map", recv, [map_arg], _, _))
+                            if map_unwrap_or::check(cx, expr, recv, map_arg, u_arg, &self.msrv) => {},
+                        _ => {
+                            unwrap_or_else_default::check(cx, expr, recv, u_arg);
+                            unnecessary_lazy_eval::check(cx, expr, recv, u_arg, "unwrap_or");
+                        },
+                    }
+                    unnecessary_literal_unwrap::check(cx, expr, recv, name);
                 },
                 ("zip", [arg]) => {
                     if let ExprKind::MethodCall(name, iter_recv, [], _) = recv.kind

tests/ui/unnecessary_literal_unwrap.fixed

@@ -1,5 +1,6 @@
 //run-rustfix
 #![warn(clippy::unnecessary_literal_unwrap)]
+#![allow(clippy::unnecessary_lazy_evaluations)]
 
 fn unwrap_option() {
     let _val = 1;
@@ -15,11 +16,13 @@ fn unwrap_result() {
 fn unwrap_methods_option() {
     let _val = 1;
     let _val = 1;
+    let _val = 1;
 }
 
 fn unwrap_methods_result() {
     let _val = 1;
     let _val = 1;
+    let _val = 1;
 }
 
 fn main() {

tests/ui/unnecessary_literal_unwrap.rs

@@ -1,5 +1,6 @@
 //run-rustfix
 #![warn(clippy::unnecessary_literal_unwrap)]
+#![allow(clippy::unnecessary_lazy_evaluations)]
 
 fn unwrap_option() {
     let _val = Some(1).unwrap();
@@ -15,11 +16,13 @@ fn unwrap_result() {
 fn unwrap_methods_option() {
     let _val = Some(1).unwrap_or(2);
     let _val = Some(1).unwrap_or_default();
+    let _val = Some(1).unwrap_or_else(|| _val);
 }
 
 fn unwrap_methods_result() {
     let _val = Ok::<usize, ()>(1).unwrap_or(2);
     let _val = Ok::<usize, ()>(1).unwrap_or_default();
+    let _val = Ok::<usize, ()>(1).unwrap_or_else(|()| _val);
 }
 
 fn main() {

tests/ui/unnecessary_literal_unwrap.stderr

@@ -1,5 +1,5 @@
 error: used `unwrap()` on `Some` value
-  --> $DIR/unnecessary_literal_unwrap.rs:5:16
+  --> $DIR/unnecessary_literal_unwrap.rs:6:16
    |
 LL |     let _val = Some(1).unwrap();
    |                ^^^^^^^^^^^^^^^^
@@ -12,7 +12,7 @@ LL +     let _val = 1;
    |
 
 error: used `expect()` on `Some` value
-  --> $DIR/unnecessary_literal_unwrap.rs:6:16
+  --> $DIR/unnecessary_literal_unwrap.rs:7:16
    |
 LL |     let _val = Some(1).expect("this never happens");
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -24,7 +24,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap()` on `Ok` value
-  --> $DIR/unnecessary_literal_unwrap.rs:10:16
+  --> $DIR/unnecessary_literal_unwrap.rs:11:16
    |
 LL |     let _val = Ok::<usize, ()>(1).unwrap();
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -36,7 +36,7 @@ LL +     let _val = 1;
    |
 
 error: used `expect()` on `Ok` value
-  --> $DIR/unnecessary_literal_unwrap.rs:11:16
+  --> $DIR/unnecessary_literal_unwrap.rs:12:16
    |
 LL |     let _val = Ok::<usize, ()>(1).expect("this never happens");
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -48,7 +48,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or()` on `Some` value
-  --> $DIR/unnecessary_literal_unwrap.rs:16:16
+  --> $DIR/unnecessary_literal_unwrap.rs:17:16
    |
 LL |     let _val = Some(1).unwrap_or(2);
    |                ^^^^^^^^^^^^^^^^^^^^
@@ -60,7 +60,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or_default()` on `Some` value
-  --> $DIR/unnecessary_literal_unwrap.rs:17:16
+  --> $DIR/unnecessary_literal_unwrap.rs:18:16
    |
 LL |     let _val = Some(1).unwrap_or_default();
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -71,8 +71,20 @@ LL -     let _val = Some(1).unwrap_or_default();
 LL +     let _val = 1;
    |
 
+error: used `unwrap_or_else()` on `Some` value
+  --> $DIR/unnecessary_literal_unwrap.rs:19:16
+   |
+LL |     let _val = Some(1).unwrap_or_else(|| _val);
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: remove the `Some` and `unwrap_or_else()`
+   |
+LL -     let _val = Some(1).unwrap_or_else(|| _val);
+LL +     let _val = 1;
+   |
+
 error: used `unwrap_or()` on `Ok` value
-  --> $DIR/unnecessary_literal_unwrap.rs:21:16
+  --> $DIR/unnecessary_literal_unwrap.rs:23:16
    |
 LL |     let _val = Ok::<usize, ()>(1).unwrap_or(2);
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -84,7 +96,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or_default()` on `Ok` value
-  --> $DIR/unnecessary_literal_unwrap.rs:22:16
+  --> $DIR/unnecessary_literal_unwrap.rs:24:16
    |
 LL |     let _val = Ok::<usize, ()>(1).unwrap_or_default();
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -95,5 +107,17 @@ LL -     let _val = Ok::<usize, ()>(1).unwrap_or_default();
 LL +     let _val = 1;
    |
 
-error: aborting due to 8 previous errors
+error: used `unwrap_or_else()` on `Ok` value
+  --> $DIR/unnecessary_literal_unwrap.rs:25:16
+   |
+LL |     let _val = Ok::<usize, ()>(1).unwrap_or_else(|()| _val);
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: remove the `Ok` and `unwrap_or_else()`
+   |
+LL -     let _val = Ok::<usize, ()>(1).unwrap_or_else(|()| _val);
+LL +     let _val = 1;
+   |
+
+error: aborting due to 10 previous errors