ban empty ident in syntax-level

Author: cometkim

jscomp/syntax/src/res_scanner.ml

@@ -291,11 +291,12 @@ let scanNumber scanner =
   else Token.Int {i = literal; suffix}
 
 let scanExoticIdentifier scanner =
-  (* TODO: are we disregarding the current char...? Should be a quote *)
-  next scanner;
   let buffer = Buffer.create 20 in
   let startPos = position scanner in
 
+  (* TODO: are we disregarding the current char...? Should be a quote *)
+  next scanner;
+
   let rec scan () =
     match scanner.ch with
     | '"' -> next scanner
@@ -315,8 +316,17 @@ let scanExoticIdentifier scanner =
       scan ()
   in
   scan ();
+
+  let ident = Buffer.contents buffer in
+  let _ =
+    if ident = "" then
+      let endPos = position scanner in
+      scanner.err ~startPos ~endPos
+        (Diagnostics.message "A quoted identifier can't be empty string.")
+  in
+
   (* TODO: do we really need to create a new buffer instead of substring once? *)
-  Token.Lident (Buffer.contents buffer)
+  Token.Lident ident
 
 let scanStringEscapeSequence ~startPos scanner =
   let scan ~n ~base ~max =

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

@@ -1,3 +1,9 @@
+type \""
+
+type \"" = int
+
+let \""
+
 let \"a
 b
 c" = 1

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

@@ -1,47 +1,97 @@
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:1:7
+  tests/parsing/errors/scanner/exoticIdent.res:1:7-8
 
-  1 │ let \"a
-  2 │ b
-  3 │ c" = 1
+  1 │ type \""
+  2 │ 
+  3 │ type \"" = int
 
-  A quoted identifier can't contain line breaks.
+  A quoted identifier can't be empty string.
 
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:2:1
+  tests/parsing/errors/scanner/exoticIdent.res:3:7-8
 
-  1 │ let \"a
-  2 │ b
-  3 │ c" = 1
+  1 │ type \""
+  2 │ 
+  3 │ type \"" = int
   4 │ 
+  5 │ let \""
 
-  Did you forget a `=` here?
+  A quoted identifier can't be empty string.
 
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:3:2-4:0
+  tests/parsing/errors/scanner/exoticIdent.res:5:6-7
 
-  1 │ let \"a
-  2 │ b
-  3 │ c" = 1
+  3 │ type \"" = int
   4 │ 
+  5 │ let \""
+  6 │ 
+  7 │ let \"a
 
-  This string is missing a double quote at the end
+  A quoted identifier can't be empty string.
 
 
   Syntax error!
-  tests/parsing/errors/scanner/exoticIdent.res:3:2-4:0
+  tests/parsing/errors/scanner/exoticIdent.res:5:8-7:3
 
-  1 │ let \"a
-  2 │ b
-  3 │ c" = 1
+  3 │ type \"" = int
   4 │ 
+  5 │ let \""
+  6 │ 
+  7 │ let \"a
+  8 │ b
+  9 │ c" = 1
+
+  Did you forget a `=` here?
+
+
+  Syntax error!
+  tests/parsing/errors/scanner/exoticIdent.res:7:6-7
+
+  5 │ let \""
+  6 │ 
+  7 │ let \"a
+  8 │ b
+  9 │ c" = 1
+
+  A quoted identifier can't contain line breaks.
+
+
+  Syntax error!
+  tests/parsing/errors/scanner/exoticIdent.res:8:1
+
+   6 │ 
+   7 │ let \"a
+   8 │ b
+   9 │ c" = 1
+  10 │ 
+
+  Did you forget a `=` here?
+
+
+  Syntax error!
+  tests/parsing/errors/scanner/exoticIdent.res:9:2-10:0
+
+   7 │ let \"a
+   8 │ b
+   9 │ c" = 1
+  10 │ 
+
+  This string is missing a double quote at the end
+
+
+  Syntax error!
+  tests/parsing/errors/scanner/exoticIdent.res:9:2-10:0
+
+   7 │ let \"a
+   8 │ b
+   9 │ c" = 1
+  10 │ 
 
   consecutive statements on a line must be separated by ';' or a newline
 
-let a = b
-;;c
-;;{js| = 1
-|js}
+type nonrec 
+type nonrec  = int
+let Fatal error: exception Invalid_argument("index out of bounds")