Suggest removing superfluous semicolos when statements used as expressions

2 files changed, 205 insertions, 0 deletions

diff --git a/tests/ui/inference/issue-105431-stmts-as-exp.rs b/tests/ui/inference/issue-105431-stmts-as-exp.rs
new file mode 100644
index 00000000000..b5adb4a2b66
--- /dev/null
+++ b/tests/ui/inference/issue-105431-stmts-as-exp.rs
@@ -0,0 +1,76 @@
+#![allow(unused)]
+
+fn test_if() -> i32 {
+    let x = if true {
+        eprintln!("hello");
+        3;
+    }
+    else {
+        4;
+    };
+    x //~ ERROR mismatched types
+}
+
+fn test_if_without_binding() -> i32 {
+    if true { //~ ERROR mismatched types
+        eprintln!("hello");
+        3;
+    }
+    else { //~ ERROR mismatched types
+        4;
+    }
+}
+
+fn test_match() -> i32 {
+    let v = 1;
+    let res = match v {
+        1 => { 1; }
+        _ => { 2; }
+    };
+    res //~ ERROR mismatched types
+}
+
+fn test_match_match_without_binding() -> i32 {
+    let v = 1;
+    match v {
+        1 => { 1; } //~ ERROR mismatched types
+        _ => { 2; } //~ ERROR mismatched types
+    }
+}
+
+fn test_match_arm_different_types() -> i32 {
+    let v = 1;
+    let res = match v {
+        1 => { if 1 < 2 { 1 } else { 2 } }
+        _ => { 2; } //~ ERROR `match` arms have incompatible types
+    };
+    res
+}
+
+fn test_if_match_mixed() -> i32 {
+    let x = if true {
+        3;
+    } else {
+        match 1 {
+            1 => { 1 }
+            _ => { 2 }
+        };
+    };
+    x //~ ERROR mismatched types
+}
+
+fn test_if_match_mixed_failed() -> i32 {
+    let x = if true {
+        3;
+    } else {
+        // because this is a tailed expr, so we won't check deeper
+        match 1 {
+            1 => { 33; }
+            _ => { 44; }
+        }
+    };
+    x //~ ERROR mismatched types
+}
+
+
+fn main() {}
diff --git a/tests/ui/inference/issue-105431-stmts-as-exp.stderr b/tests/ui/inference/issue-105431-stmts-as-exp.stderr
new file mode 100644
index 00000000000..2878d602ec5
--- /dev/null
+++ b/tests/ui/inference/issue-105431-stmts-as-exp.stderr
@@ -0,0 +1,129 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:11:5
+   |
+LL | fn test_if() -> i32 {
+   |                 --- expected `i32` because of return type
+...
+LL |     x
+   |     ^ expected `i32`, found `()`
+   |
+help: remove this semicolon to return this value
+   |
+LL -         3;
+LL +         3
+   |
+help: remove this semicolon to return this value
+   |
+LL -         4;
+LL +         4
+   |
+
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:15:13
+   |
+LL |       if true {
+   |  _____________^
+LL | |         eprintln!("hello");
+LL | |         3;
+   | |          - help: remove this semicolon to return this value
+LL | |     }
+   | |_____^ expected `i32`, found `()`
+
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:19:10
+   |
+LL |       else {
+   |  __________^
+LL | |         4;
+   | |          - help: remove this semicolon to return this value
+LL | |     }
+   | |_____^ expected `i32`, found `()`
+
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:30:5
+   |
+LL | fn test_match() -> i32 {
+   |                    --- expected `i32` because of return type
+...
+LL |     res
+   |     ^^^ expected `i32`, found `()`
+   |
+help: remove this semicolon to return this value
+   |
+LL -         1 => { 1; }
+LL +         1 => { 1 }
+   |
+help: remove this semicolon to return this value
+   |
+LL -         _ => { 2; }
+LL +         _ => { 2 }
+   |
+
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:36:14
+   |
+LL |         1 => { 1; }
+   |              ^^^-^^
+   |              |  |
+   |              |  help: remove this semicolon to return this value
+   |              expected `i32`, found `()`
+
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:37:14
+   |
+LL |         _ => { 2; }
+   |              ^^^-^^
+   |              |  |
+   |              |  help: remove this semicolon to return this value
+   |              expected `i32`, found `()`
+
+error[E0308]: `match` arms have incompatible types
+  --> $DIR/issue-105431-stmts-as-exp.rs:45:16
+   |
+LL |       let res = match v {
+   |  _______________-
+LL | |         1 => { if 1 < 2 { 1 } else { 2 } }
+   | |                ------------------------- this is found to be of type `{integer}`
+LL | |         _ => { 2; }
+   | |                ^-
+   | |                ||
+   | |                |help: consider removing this semicolon
+   | |                expected integer, found `()`
+LL | |     };
+   | |_____- `match` arms have incompatible types
+
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:59:5
+   |
+LL | fn test_if_match_mixed() -> i32 {
+   |                             --- expected `i32` because of return type
+...
+LL |     x
+   |     ^ expected `i32`, found `()`
+   |
+help: remove this semicolon to return this value
+   |
+LL -         3;
+LL +         3
+   |
+help: remove this semicolon to return this value
+   |
+LL -         };
+LL +         }
+   |
+
+error[E0308]: mismatched types
+  --> $DIR/issue-105431-stmts-as-exp.rs:72:5
+   |
+LL | fn test_if_match_mixed_failed() -> i32 {
+   |                                    --- expected `i32` because of return type
+LL |     let x = if true {
+LL |         3;
+   |          - help: remove this semicolon to return this value
+...
+LL |     x
+   |     ^ expected `i32`, found `()`
+
+error: aborting due to 9 previous errors
+
+For more information about this error, try `rustc --explain E0308`.