Add test doc-comment-after-comma-issue-142311.rs

Signed-off-by: xizheyin <[email protected]>

Author: xizheyin

tests/ui/parser/doc-comment-after-missing-comma-issue-142311.rs

@@ -0,0 +1,18 @@
+//! Check that the parser does not suggest converting `///` to a regular comment
+//! when it appears after a missing comma in an item list (e.g. `enum` variants).
+//!
+//! Related issue
+//! - https://github.com/rust-lang/rust/issues/142311
+
+enum Foo {
+    /// Like the noise a sheep makes
+    Bar
+    /// Like where people drink
+    //~^ ERROR expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `/// Like where people drink`
+    Baa///xxxxxx
+    //~^ ERROR expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `///xxxxxx`
+    Baz///xxxxxx
+    //~^ ERROR expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `///xxxxxx`
+}
+
+fn main() {}

tests/ui/parser/doc-comment-after-missing-comma-issue-142311.stderr

@@ -0,0 +1,47 @@
+error: expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `/// Like where people drink`
+  --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:10:5
+   |
+LL |     Bar
+   |        - expected one of `(`, `,`, `=`, `{`, or `}`
+LL |     /// Like where people drink
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ unexpected token
+   |
+help: add a space before the last `/` to write a regular comment
+   |
+LL |     // / Like where people drink
+   |       +
+help: missing `,`
+   |
+LL |     Bar,
+   |        +
+
+error: expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `///xxxxxx`
+  --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:12:8
+   |
+LL |     Baa///xxxxxx
+   |        ^^^^^^^^^ expected one of `(`, `,`, `=`, `{`, or `}`
+   |
+help: add a space before the last `/` to write a regular comment
+   |
+LL |     Baa// /xxxxxx
+   |          +
+help: missing `,`
+   |
+LL |     Baa,///xxxxxx
+   |        +
+
+error: expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `///xxxxxx`
+  --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:14:8
+   |
+LL |     Baz///xxxxxx
+   |        ^^^^^^^^^ expected one of `(`, `,`, `=`, `{`, or `}`
+   |
+   = help: doc comments must come before what they document, if a comment was intended use `//`
+   = help: enum variants can be `Variant`, `Variant = <integer>`, `Variant(Type, ..., TypeN)` or `Variant { fields: Types }`
+help: add a space before the last `/` to write a regular comment
+   |
+LL |     Baz// /xxxxxx
+   |          +
+
+error: aborting due to 3 previous errors
+