better / more tests

Author: anmonteiro

formatTest/unit_tests/expected_output/infix.re

@@ -1206,3 +1206,5 @@ let foo = (a, b) => a =- b;
 let (=\>) = (a, b) => a + b;
 
 let x = a =\> b;
+
+let (=>>) = (a, b) => a + b;

formatTest/unit_tests/input/infix.re

@@ -923,3 +923,5 @@ let foo = (a, b) => a =- b;
 let (=\>) = (a, b) => a + b;
 
 let x = a =\> b;
+
+let (=>>) = (a, b) => a + b;

src/reason-parser/reason_lexer.mll

@@ -600,7 +600,7 @@ rule token = parse
       { INFIXOP_WITH_EQUAL(lexeme_operator lexbuf) }
   (* `=\>` is treated especially due to conflicts with the function declaration
      syntax *)
-  | '\\'? '=' '\\'? '>' operator_chars*
+  | '\\'? "=\\>"
             { INFIXOP0(lexeme_operator lexbuf) }
   | '\\'? '@' operator_chars*
             { INFIXOP1(lexeme_operator lexbuf) }