fix a crash

Author: cometkim

jscomp/syntax/src/res_scanner.ml

@@ -285,12 +285,15 @@ let scanNumber scanner =
 let scanExoticIdentifier scanner =
   let startPos = position scanner in
   let startOff = scanner.offset in
+  let closed = ref false in
 
   next2 scanner;
 
   let rec scan () =
     match scanner.ch with
-    | '"' -> next scanner
+    | '"' ->
+      closed := true;
+      next scanner
     | '\n' | '\r' ->
       (* line break *)
       let endPos = position scanner in
@@ -310,20 +313,23 @@ let scanExoticIdentifier scanner =
   let ident =
     (String.sub [@doesNotRaise]) scanner.src startOff (scanner.offset - startOff)
   in
-  let name =
-    (String.sub [@doesNotRaise]) scanner.src (startOff + 2)
-      (scanner.offset - startOff - 3)
-  in
-
-  let _ =
-    if name = String.empty then
+  if not !closed then (
+    let endPos = position scanner in
+    scanner.err ~startPos ~endPos
+      (Diagnostics.message "Did you forget a \" here?");
+    Token.Lident ident)
+  else
+    let name =
+      (String.sub [@doesNotRaise]) scanner.src (startOff + 2)
+        (scanner.offset - startOff - 3)
+    in
+    if name = String.empty then (
       let endPos = position scanner in
       scanner.err ~startPos ~endPos
-        (Diagnostics.message "A quoted identifier can't be empty string.")
-  in
-
-  if Token.isInfixOperatorTxt name then Token.Lident name
-  else Token.Lident ident
+        (Diagnostics.message "A quoted identifier can't be empty string.");
+      Token.Lident ident)
+    else if Token.isInfixOperatorTxt name then Token.Lident name
+    else Token.Lident ident
 
 let scanStringEscapeSequence ~startPos scanner =
   let scan ~n ~base ~max =

jscomp/syntax/tests/parsing/errors/scanner/expected/exoticIdent.res.txt

@@ -1,6 +1,6 @@
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:1:7-8
+  tests/parsing/errors/scanner/exoticIdent.res:1:6-8
 
   1 │ type \""
   2 │ 
@@ -10,7 +10,7 @@
 
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:3:7-8
+  tests/parsing/errors/scanner/exoticIdent.res:3:6-8
 
   1 │ type \""
   2 │ 
@@ -22,7 +22,7 @@
 
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:5:6-7
+  tests/parsing/errors/scanner/exoticIdent.res:5:5-7
 
   3 │ type \"" = int
   4 │ 
@@ -48,7 +48,7 @@
 
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:7:6-7
+  tests/parsing/errors/scanner/exoticIdent.res:7:5-7
 
   5 │ let \""
   6 │ 
@@ -59,6 +59,19 @@
   A quoted identifier can't contain line breaks.
 
 
+  Syntax error!
+  tests/parsing/errors/scanner/exoticIdent.res:7:5-8:0
+
+   5 │ let \""
+   6 │ 
+   7 │ let \"a
+   8 │ b
+   9 │ c" = 1
+  10 │ 
+
+  Did you forget a " here?
+
+
   Syntax error!
   tests/parsing/errors/scanner/exoticIdent.res:8:1
 
@@ -92,6 +105,11 @@
 
   consecutive statements on a line must be separated by ';' or a newline
 
-type nonrec 
-type nonrec  = int
-let Fatal error: exception Invalid_argument("index out of bounds")
+type nonrec \""
+type nonrec \"" = int
+let \"" = [%rescript.exprhole ]
+let \"a
+ = b
+;;c
+;;{js| = 1
+|js}