Recognize Err

pksunkara · pksunkara · commit 69af0e13b266 · 2023-06-12T16:19:26.000+01:00
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
@@ -3666,7 +3666,10 @@ impl Methods {
                     }
                     unnecessary_literal_unwrap::check(cx, expr, recv, name);
                 },
-                ("expect_err", [_]) => expect_used::check(cx, expr, recv, true, self.allow_expect_in_tests),
+                ("expect_err", [_]) => {
+                    unnecessary_literal_unwrap::check(cx, expr, recv, name);
+                    expect_used::check(cx, expr, recv, true, self.allow_expect_in_tests);
+                },
                 ("extend", [arg]) => {
                     string_extend_chars::check(cx, expr, recv, arg);
                     extend_with_drain::check(cx, expr, recv, arg);
@@ -3874,7 +3877,10 @@ impl Methods {
                     unnecessary_literal_unwrap::check(cx, expr, recv, name);
                     unwrap_used::check(cx, expr, recv, false, self.allow_unwrap_in_tests);
                 },
-                ("unwrap_err", []) => unwrap_used::check(cx, expr, recv, true, self.allow_unwrap_in_tests),
+                ("unwrap_err", []) => {
+                    unnecessary_literal_unwrap::check(cx, expr, recv, name);
+                    unwrap_used::check(cx, expr, recv, true, self.allow_unwrap_in_tests)
+                },
                 ("unwrap_or", [u_arg]) => {
                     match method_call(recv) {
                         Some((arith @ ("checked_add" | "checked_sub" | "checked_mul"), lhs, [rhs], _, _)) => {
diff --git a/clippy_lints/src/methods/unnecessary_literal_unwrap.rs b/clippy_lints/src/methods/unnecessary_literal_unwrap.rs
@@ -9,18 +9,16 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr
     let init = clippy_utils::expr_or_init(cx, recv);
 
     if let hir::ExprKind::Call(call, [arg]) = init.kind {
-        let mess = if is_res_lang_ctor(cx, path_res(cx, call), hir::LangItem::OptionSome) {
-            Some("Some")
+        let constructor = if is_res_lang_ctor(cx, path_res(cx, call), hir::LangItem::OptionSome) {
+            "Some"
         } else if is_res_lang_ctor(cx, path_res(cx, call), hir::LangItem::ResultOk) {
-            Some("Ok")
+            "Ok"
+        } else if is_res_lang_ctor(cx, path_res(cx, call), hir::LangItem::ResultErr) {
+            "Err"
         } else {
-            None
+            return;
         };
 
-        let Some(constructor) = mess else {
-	    return;
-	};
-
         if init.span == recv.span {
             span_lint_and_then(
                 cx,
diff --git a/tests/ui/unnecessary_literal_unwrap.fixed b/tests/ui/unnecessary_literal_unwrap.fixed
@@ -7,10 +7,14 @@ fn unwrap_option() {
     let _val = 1;
 }
 
-fn unwrap_result() {
+fn unwrap_result_ok() {
+    let _val = 1;
+    let _val = 1;
+}
+
+fn unwrap_result_err() {
     let _val = 1;
     let _val = 1;
-    // let val = Err(1).unwrap_err();
 }
 
 fn unwrap_methods_option() {
@@ -27,7 +31,8 @@ fn unwrap_methods_result() {
 
 fn main() {
     unwrap_option();
-    unwrap_result();
+    unwrap_result_ok();
+    unwrap_result_err();
     unwrap_methods_option();
     unwrap_methods_result();
 }
diff --git a/tests/ui/unnecessary_literal_unwrap.rs b/tests/ui/unnecessary_literal_unwrap.rs
@@ -7,10 +7,14 @@ fn unwrap_option() {
     let _val = Some(1).expect("this never happens");
 }
 
-fn unwrap_result() {
+fn unwrap_result_ok() {
     let _val = Ok::<usize, ()>(1).unwrap();
     let _val = Ok::<usize, ()>(1).expect("this never happens");
-    // let val = Err(1).unwrap_err();
+}
+
+fn unwrap_result_err() {
+    let _val = Err::<(), usize>(1).unwrap_err();
+    let _val = Err::<(), usize>(1).expect_err("this never happens");
 }
 
 fn unwrap_methods_option() {
@@ -27,7 +31,8 @@ fn unwrap_methods_result() {
 
 fn main() {
     unwrap_option();
-    unwrap_result();
+    unwrap_result_ok();
+    unwrap_result_err();
     unwrap_methods_option();
     unwrap_methods_result();
 }
diff --git a/tests/ui/unnecessary_literal_unwrap.stderr b/tests/ui/unnecessary_literal_unwrap.stderr
@@ -47,9 +47,33 @@ LL -     let _val = Ok::<usize, ()>(1).expect("this never happens");
 LL +     let _val = 1;
    |
 
-error: used `unwrap_or()` on `Some` value
+error: used `unwrap_err()` on `Err` value
+  --> $DIR/unnecessary_literal_unwrap.rs:16:16
+   |
+LL |     let _val = Err::<(), usize>(1).unwrap_err();
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: remove the `Err` and `unwrap_err()`
+   |
+LL -     let _val = Err::<(), usize>(1).unwrap_err();
+LL +     let _val = 1;
+   |
+
+error: used `expect_err()` on `Err` value
   --> $DIR/unnecessary_literal_unwrap.rs:17:16
    |
+LL |     let _val = Err::<(), usize>(1).expect_err("this never happens");
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: remove the `Err` and `expect_err()`
+   |
+LL -     let _val = Err::<(), usize>(1).expect_err("this never happens");
+LL +     let _val = 1;
+   |
+
+error: used `unwrap_or()` on `Some` value
+  --> $DIR/unnecessary_literal_unwrap.rs:21:16
+   |
 LL |     let _val = Some(1).unwrap_or(2);
    |                ^^^^^^^^^^^^^^^^^^^^
    |
@@ -60,7 +84,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or_default()` on `Some` value
-  --> $DIR/unnecessary_literal_unwrap.rs:18:16
+  --> $DIR/unnecessary_literal_unwrap.rs:22:16
    |
 LL |     let _val = Some(1).unwrap_or_default();
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -72,7 +96,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or_else()` on `Some` value
-  --> $DIR/unnecessary_literal_unwrap.rs:19:16
+  --> $DIR/unnecessary_literal_unwrap.rs:23:16
    |
 LL |     let _val = Some(1).unwrap_or_else(|| _val);
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -84,7 +108,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or()` on `Ok` value
-  --> $DIR/unnecessary_literal_unwrap.rs:23:16
+  --> $DIR/unnecessary_literal_unwrap.rs:27:16
    |
 LL |     let _val = Ok::<usize, ()>(1).unwrap_or(2);
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -96,7 +120,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or_default()` on `Ok` value
-  --> $DIR/unnecessary_literal_unwrap.rs:24:16
+  --> $DIR/unnecessary_literal_unwrap.rs:28:16
    |
 LL |     let _val = Ok::<usize, ()>(1).unwrap_or_default();
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -108,7 +132,7 @@ LL +     let _val = 1;
    |
 
 error: used `unwrap_or_else()` on `Ok` value
-  --> $DIR/unnecessary_literal_unwrap.rs:25:16
+  --> $DIR/unnecessary_literal_unwrap.rs:29:16
    |
 LL |     let _val = Ok::<usize, ()>(1).unwrap_or_else(|()| _val);
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -119,5 +143,5 @@ LL -     let _val = Ok::<usize, ()>(1).unwrap_or_else(|()| _val);
 LL +     let _val = 1;
    |
 
-error: aborting due to 10 previous errors
+error: aborting due to 12 previous errors
 

Original file line number	Diff line number	Diff line change
`@@ -47,9 +47,33 @@ LL - let _val = Ok::<usize, ()>(1).expect("this never happens");`
`47`	`47`	`LL + let _val = 1;`
`48`	`48`	`\|`
`49`	`49`
`50`		-error: used `unwrap_or()` on `Some` value
	`50`	+error: used `unwrap_err()` on `Err` value
	`51`	`+ --> $DIR/unnecessary_literal_unwrap.rs:16:16`
	`52`	`+ \|`
	`53`	`+LL \| let _val = Err::<(), usize>(1).unwrap_err();`
	`54`	`+ \| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
	`55`	`+ \|`
	`56`	+help: remove the `Err` and `unwrap_err()`
	`57`	`+ \|`
	`58`	`+LL - let _val = Err::<(), usize>(1).unwrap_err();`
	`59`	`+LL + let _val = 1;`
	`60`	`+ \|`
	`61`	`+`
	`62`	+error: used `expect_err()` on `Err` value
`51`	`63`	`--> $DIR/unnecessary_literal_unwrap.rs:17:16`
`52`	`64`	`\|`
	`65`	`+LL \| let _val = Err::<(), usize>(1).expect_err("this never happens");`
	`66`	`+ \| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
	`67`	`+ \|`
	`68`	+help: remove the `Err` and `expect_err()`
	`69`	`+ \|`
	`70`	`+LL - let _val = Err::<(), usize>(1).expect_err("this never happens");`
	`71`	`+LL + let _val = 1;`
	`72`	`+ \|`
	`73`	`+`
	`74`	+error: used `unwrap_or()` on `Some` value
	`75`	`+ --> $DIR/unnecessary_literal_unwrap.rs:21:16`
	`76`	`+ \|`
`53`	`77`	`LL \| let _val = Some(1).unwrap_or(2);`
`54`	`78`	`\| ^^^^^^^^^^^^^^^^^^^^`
`55`	`79`	`\|`
`@@ -60,7 +84,7 @@ LL + let _val = 1;`
`60`	`84`	`\|`
`61`	`85`
`62`	`86`	error: used `unwrap_or_default()` on `Some` value
`63`		`- --> $DIR/unnecessary_literal_unwrap.rs:18:16`
	`87`	`+ --> $DIR/unnecessary_literal_unwrap.rs:22:16`
`64`	`88`	`\|`
`65`	`89`	`LL \| let _val = Some(1).unwrap_or_default();`
`66`	`90`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`@@ -72,7 +96,7 @@ LL + let _val = 1;`
`72`	`96`	`\|`
`73`	`97`
`74`	`98`	error: used `unwrap_or_else()` on `Some` value
`75`		`- --> $DIR/unnecessary_literal_unwrap.rs:19:16`
	`99`	`+ --> $DIR/unnecessary_literal_unwrap.rs:23:16`
`76`	`100`	`\|`
`77`	`101`	`LL \| let _val = Some(1).unwrap_or_else(\|\| _val);`
`78`	`102`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`@@ -84,7 +108,7 @@ LL + let _val = 1;`
`84`	`108`	`\|`
`85`	`109`
`86`	`110`	error: used `unwrap_or()` on `Ok` value
`87`		`- --> $DIR/unnecessary_literal_unwrap.rs:23:16`
	`111`	`+ --> $DIR/unnecessary_literal_unwrap.rs:27:16`
`88`	`112`	`\|`
`89`	`113`	`LL \| let _val = Ok::<usize, ()>(1).unwrap_or(2);`
`90`	`114`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`@@ -96,7 +120,7 @@ LL + let _val = 1;`
`96`	`120`	`\|`
`97`	`121`
`98`	`122`	error: used `unwrap_or_default()` on `Ok` value
`99`		`- --> $DIR/unnecessary_literal_unwrap.rs:24:16`
	`123`	`+ --> $DIR/unnecessary_literal_unwrap.rs:28:16`
`100`	`124`	`\|`
`101`	`125`	`LL \| let _val = Ok::<usize, ()>(1).unwrap_or_default();`
`102`	`126`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`@@ -108,7 +132,7 @@ LL + let _val = 1;`
`108`	`132`	`\|`
`109`	`133`
`110`	`134`	error: used `unwrap_or_else()` on `Ok` value
`111`		`- --> $DIR/unnecessary_literal_unwrap.rs:25:16`
	`135`	`+ --> $DIR/unnecessary_literal_unwrap.rs:29:16`
`112`	`136`	`\|`
`113`	`137`	`LL \| let _val = Ok::<usize, ()>(1).unwrap_or_else(\|()\| _val);`
`114`	`138`	`\| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^`
`@@ -119,5 +143,5 @@ LL - let _val = Ok::<usize, ()>(1).unwrap_or_else(\|()\| _val);`
`119`	`143`	`LL + let _val = 1;`
`120`	`144`	`\|`
`121`	`145`
`122`		`-error: aborting due to 10 previous errors`
	`146`	`+error: aborting due to 12 previous errors`
`123`	`147`