feat(compiler): Correct lexer error in malformed match (#2370)

Author: spotandjake

compiler/src/parsing/wrapped_lexer.re

@@ -437,3 +437,30 @@ let token = state => {
     triple;
   };
 };
+
+let print_syntax_error =
+  Printf.(
+    Location.(
+      fun
+      | Lex_fast_forward_failed(acc, None) => {
+          let loc =
+            switch (List.rev(acc)) {
+            | [_, (tkn, loc_start, loc_end), ..._] => {
+                loc_start,
+                loc_end,
+                loc_ghost: false,
+              }
+            | [(tkn, loc_start, loc_end), ..._] => {
+                loc_start,
+                loc_end,
+                loc_ghost: false,
+              }
+            | [] => Location.dummy_loc
+            };
+          Some(errorf(~loc, "Syntax error."));
+        }
+      | _ => None
+    )
+  );
+
+let _ = Location.register_error_of_exn(print_syntax_error);

compiler/test/suites/parsing.re

@@ -563,4 +563,7 @@ describe("parsing", ({test, testSkip}) => {
       prog_core_loc: Location.dummy_loc,
     },
   );
+  // Regression for #2369
+  assertCompileError("lexer_hack_match_1", "(match { })", "Syntax error.");
+  assertCompileError("lexer_hack_match_2", "(match (true)", "Syntax error.");
 });