Test tuple suggestions, including tuple-as-function-argument

Author: bobrippling

src/test/ui/suggestions/args-instead-of-tuple.fixed

@@ -0,0 +1,18 @@
+// Test suggesting tuples where bare arguments may have been passed
+// See issue #86481 for details.
+
+// run-rustfix
+
+fn main() {
+    let _: Result<(i32, i8), ()> = Ok((1, 2));
+    //~^ ERROR this enum variant takes 1 argument but 2 arguments were supplied
+    let _: Option<(i32, i8, &'static str)> = Some((1, 2, "hi"));
+    //~^ ERROR this enum variant takes 1 argument but 3 arguments were supplied
+    let _: Option<()> = Some(());
+    //~^ ERROR this enum variant takes 1 argument but 0 arguments were supplied
+
+    f((1, 2)); //~ ERROR this function takes 1 argument
+}
+
+fn f(_: (i32, i32)) {
+}

src/test/ui/suggestions/args-instead-of-tuple.rs

@@ -0,0 +1,18 @@
+// Test suggesting tuples where bare arguments may have been passed
+// See issue #86481 for details.
+
+// run-rustfix
+
+fn main() {
+    let _: Result<(i32, i8), ()> = Ok(1, 2);
+    //~^ ERROR this enum variant takes 1 argument but 2 arguments were supplied
+    let _: Option<(i32, i8, &'static str)> = Some(1, 2, "hi");
+    //~^ ERROR this enum variant takes 1 argument but 3 arguments were supplied
+    let _: Option<()> = Some();
+    //~^ ERROR this enum variant takes 1 argument but 0 arguments were supplied
+
+    f(1, 2); //~ ERROR this function takes 1 argument
+}
+
+fn f(_: (i32, i32)) {
+}

src/test/ui/suggestions/args-instead-of-tuple.stderr

@@ -0,0 +1,52 @@
+error[E0061]: this enum variant takes 1 argument but 2 arguments were supplied
+  --> $DIR/args-instead-of-tuple.rs:7:36
+   |
+LL |     let _: Result<(i32, i8), ()> = Ok(1, 2);
+   |                                    ^^ -  - supplied 2 arguments
+   |
+help: use parentheses to construct a tuple
+   |
+LL |     let _: Result<(i32, i8), ()> = Ok((1, 2));
+   |                                       +    +
+
+error[E0061]: this enum variant takes 1 argument but 3 arguments were supplied
+  --> $DIR/args-instead-of-tuple.rs:9:46
+   |
+LL |     let _: Option<(i32, i8, &'static str)> = Some(1, 2, "hi");
+   |                                              ^^^^ -  -  ---- supplied 3 arguments
+   |
+help: use parentheses to construct a tuple
+   |
+LL |     let _: Option<(i32, i8, &'static str)> = Some((1, 2, "hi"));
+   |                                                   +          +
+
+error[E0061]: this enum variant takes 1 argument but 0 arguments were supplied
+  --> $DIR/args-instead-of-tuple.rs:11:25
+   |
+LL |     let _: Option<()> = Some();
+   |                         ^^^^-- supplied 0 arguments
+   |
+help: expected the unit value `()`; create it with empty parentheses
+   |
+LL |     let _: Option<()> = Some(());
+   |                              ++
+
+error[E0061]: this function takes 1 argument but 2 arguments were supplied
+  --> $DIR/args-instead-of-tuple.rs:14:5
+   |
+LL |     f(1, 2);
+   |     ^ -  - supplied 2 arguments
+   |
+note: function defined here
+  --> $DIR/args-instead-of-tuple.rs:17:4
+   |
+LL | fn f(_: (i32, i32)) {
+   |    ^ -------------
+help: use parentheses to construct a tuple
+   |
+LL |     f((1, 2));
+   |       +    +
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0061`.