[flow][match] Error on unary pattern + on bigint literal

Summary:
Error on unary pattern `+` on bigint literal (e.g. `+1n`). This is not allowed in JS in general.

Changelog: [internal]

Reviewed By: SamChou19815

Differential Revision: D67502323

fbshipit-source-id: 0471e0d1093e2026beebf7353fb9c01c5139cbe8

src/typing/debug_js.ml

@@ -1908,6 +1908,8 @@ let dump_error_message =
     | EMatchInvalidObjectPropertyLiteral { loc } ->
       spf "EMatchInvalidObjectPropertyLiteral (%s)" (string_of_aloc loc)
     | EMatchInvalidUnaryZero { loc } -> spf "EMatchInvalidUnaryZero (%s)" (string_of_aloc loc)
+    | EMatchInvalidUnaryPlusBigInt { loc } ->
+      spf "EMatchInvalidUnaryBigInt (%s)" (string_of_aloc loc)
     | EDevOnlyRefinedLocInfo { refined_loc; refining_locs = _ } ->
       spf "EDevOnlyRefinedLocInfo {refined_loc=%s}" (string_of_aloc refined_loc)
     | EDevOnlyInvalidatedRefinementInfo { read_loc; invalidation_info = _ } ->

src/typing/errors/error_message.ml

@@ -624,6 +624,7 @@ and 'loc t' =
     }
   | EMatchInvalidObjectPropertyLiteral of { loc: 'loc }
   | EMatchInvalidUnaryZero of { loc: 'loc }
+  | EMatchInvalidUnaryPlusBigInt of { loc: 'loc }
   (* Dev only *)
   | EDevOnlyRefinedLocInfo of {
       refined_loc: 'loc;
@@ -1430,6 +1431,7 @@ let rec map_loc_of_error_message (f : 'a -> 'b) : 'a t' -> 'b t' =
   | EMatchInvalidBindingKind { loc; kind } -> EMatchInvalidBindingKind { loc = f loc; kind }
   | EMatchInvalidObjectPropertyLiteral { loc } -> EMatchInvalidObjectPropertyLiteral { loc = f loc }
   | EMatchInvalidUnaryZero { loc } -> EMatchInvalidUnaryZero { loc = f loc }
+  | EMatchInvalidUnaryPlusBigInt { loc } -> EMatchInvalidUnaryPlusBigInt { loc = f loc }
   | EDevOnlyInvalidatedRefinementInfo { read_loc; invalidation_info } ->
     EDevOnlyInvalidatedRefinementInfo
       {
@@ -1730,7 +1732,8 @@ let util_use_op_of_msg nope util = function
   | EMatchNotExhaustive _
   | EMatchInvalidBindingKind _
   | EMatchInvalidObjectPropertyLiteral _
-  | EMatchInvalidUnaryZero _ ->
+  | EMatchInvalidUnaryZero _
+  | EMatchInvalidUnaryPlusBigInt _ ->
     nope
 
 (* Not all messages (i.e. those whose locations are based on use_ops) have locations that can be
@@ -1935,6 +1938,7 @@ let loc_of_msg : 'loc t' -> 'loc option = function
   | EMatchInvalidBindingKind { loc; _ } -> Some loc
   | EMatchInvalidObjectPropertyLiteral { loc } -> Some loc
   | EMatchInvalidUnaryZero { loc } -> Some loc
+  | EMatchInvalidUnaryPlusBigInt { loc } -> Some loc
   | EDevOnlyRefinedLocInfo { refined_loc; refining_locs = _ } -> Some refined_loc
   | EDevOnlyInvalidatedRefinementInfo { read_loc; invalidation_info = _ } -> Some read_loc
   | EUnableToSpread _
@@ -2887,6 +2891,7 @@ let friendly_message_of_msg = function
   | EMatchInvalidObjectPropertyLiteral { loc = _ } ->
     Normal MessageMatchInvalidObjectPropertyLiteral
   | EMatchInvalidUnaryZero { loc = _ } -> Normal MessageMatchInvalidUnaryZero
+  | EMatchInvalidUnaryPlusBigInt { loc = _ } -> Normal MessageMatchInvalidUnaryPlusBigInt
 
 let defered_in_speculation = function
   | EUntypedTypeImport _
@@ -3227,3 +3232,4 @@ let error_code_of_message err : error_code option =
   | EMatchInvalidBindingKind _ -> Some MatchInvalidPattern
   | EMatchInvalidObjectPropertyLiteral _ -> Some MatchInvalidPattern
   | EMatchInvalidUnaryZero _ -> Some MatchInvalidPattern
+  | EMatchInvalidUnaryPlusBigInt _ -> Some MatchInvalidPattern

src/typing/errors/flow_intermediate_error.ml

@@ -4004,6 +4004,8 @@ let to_printable_error :
       ]
     | MessageMatchInvalidUnaryZero ->
       [text "Unary pattern on "; code "0"; text " is not supported."]
+    | MessageMatchInvalidUnaryPlusBigInt ->
+      [text "Unary pattern "; code "+"; text " on bigint literal is not supported."]
   in
   let rec convert_error_message { kind; loc; error_code; root; message; misplaced_source_file = _ }
       =

src/typing/errors/flow_intermediate_error_types.ml

@@ -901,6 +901,7 @@ type 'loc message =
   | MessageMatchInvalidBindingKind of { kind: Flow_ast.Variable.kind }
   | MessageMatchInvalidObjectPropertyLiteral
   | MessageMatchInvalidUnaryZero
+  | MessageMatchInvalidUnaryPlusBigInt
 
 type 'loc intermediate_error = {
   kind: Flow_errors_utils.error_kind;

src/typing/match_pattern.ml

@@ -140,10 +140,12 @@ let rec pattern cx ~on_identifier ~on_expression ~on_binding acc (loc, p) :
     | BooleanPattern x -> BooleanPattern x
     | NullPattern x -> NullPattern x
     | UnaryPattern x ->
-      let { UnaryPattern.argument; _ } = x in
-      (match argument with
-      | (_, UnaryPattern.NumberLiteral { Ast.NumberLiteral.value = 0.0; _ }) ->
+      let { UnaryPattern.operator; argument; _ } = x in
+      (match (operator, argument) with
+      | (_, (_, UnaryPattern.NumberLiteral { Ast.NumberLiteral.value = 0.0; _ })) ->
         Flow_js.add_output cx (Error_message.EMatchInvalidUnaryZero { loc })
+      | (UnaryPattern.Plus, (_, UnaryPattern.BigIntLiteral _)) ->
+        Flow_js.add_output cx (Error_message.EMatchInvalidUnaryPlusBigInt { loc })
       | _ -> ());
       UnaryPattern x
     | MemberPattern mem ->

tests/match/match.exp

@@ -502,6 +502,14 @@ Unary pattern on `0` is not supported. [match-invalid-pattern]
            ^^
 
 
+Error ------------------------------------------------------------------------------------------- pattern-errors.js:46:5
+
+Unary pattern `+` on bigint literal is not supported. [match-invalid-pattern]
+
+   46|     +1n: true, // ERROR
+           ^^^
+
+
 Error -------------------------------------------------------------------------------------------------- patterns.js:9:3
 
 Cannot cast `out` to empty because number [1] is incompatible with empty [2]. [incompatible-cast]
@@ -627,4 +635,4 @@ References:
 
 
 
-Found 47 errors
+Found 48 errors

tests/match/pattern-errors.js

@@ -37,3 +37,13 @@
     0: true, // OK
   };
 }
+
+// Unary `+` on bigint banned
+{
+  declare const x: 1n;
+
+  const e1 = match (x) {
+    +1n: true, // ERROR
+    1n: true, // OK
+  };
+}