[flow][match] Autocomplete for identifier patterns in match expressions

Summary:
Autocomplete for identifier patterns in match expressions.
Also, tests confirming that we don't autocomplete binding pattern names, and don't autocomplete object pattern keys with local identifiers.

Changelog: [internal]

Reviewed By: panagosg7

Differential Revision: D67830066

fbshipit-source-id: 50d03368b9c586ad4e1e19418c5877e52e2b3d7c

src/services/autocomplete/autocomplete_js.ml

@@ -925,6 +925,20 @@ class process_request_searcher cx ~from_trigger_character ~cursor =
         this#find loc name Ac_type_binding
       else
         id
+
+    (* Don't autocomplete match object pattern property keys. *)
+    method! match_object_pattern_property_key key =
+      let open Ast.MatchPattern.ObjectPattern.Property in
+      let (loc, token) =
+        match key with
+        | StringLiteral (loc, { Ast.StringLiteral.raw; _ }) -> (loc, raw)
+        | NumberLiteral (loc, { Ast.NumberLiteral.raw; _ }) -> (loc, raw)
+        | Identifier (loc, { Ast.Identifier.name; _ }) -> (loc, name)
+      in
+      if this#covers_target loc then
+        this#find loc token Ac_ignored
+      else
+        key
   end
 
 let autocomplete_id ~cursor _cx _ac_name ac_loc = covers_target cursor ac_loc

src/services/autocomplete/keywords.ml

@@ -16,6 +16,7 @@ type context_node =
   | ObjectKey
   | Type
   | SwitchCase
+  | MatchPattern
 
 (* TODO: include `of`, `in`, and `instanceof`. We don't currently autocomplete at positions where those are valid. *)
 (* true, false, and null are not included here, because we already suggest those when we have type info *)
@@ -103,6 +104,8 @@ let export_default_keywords ~component_syntax_enabled =
   else
     []
 
+let match_pattern_keywords = ["const"]
+
 exception Found of context_node list
 
 class mapper target =
@@ -145,6 +148,9 @@ class mapper target =
 
     method! switch_case case = this#with_context SwitchCase (fun () -> super#switch_case case)
 
+    method! match_pattern pattern =
+      this#with_context MatchPattern (fun () -> super#match_pattern pattern)
+
     method! identifier (loc, id) =
       if this#target_contained_by loc then raise (Found context);
       super#identifier (loc, id)
@@ -162,6 +168,7 @@ let keywords_of_context ~component_syntax_enabled ~pattern_matching_expressions_
   | Expression :: SwitchCase :: _ ->
     []
   | Expression :: _ -> expression_keywords ~pattern_matching_expressions_enabled
+  | MatchPattern :: _ when pattern_matching_expressions_enabled -> match_pattern_keywords
   | _ -> []
 
 let keywords_at_loc ~component_syntax_enabled ~pattern_matching_expressions_enabled ast loc =

tests/autocomplete_match/autocomplete_match.exp

@@ -17,3 +17,31 @@ Flags: --pretty
   ]
 }
 
+pattern-identifier.js:6:5
+Flags: --pretty
+{"result":[{"name":"foo","type":"1"}]}
+
+pattern-binding.js:6:14
+Flags: --pretty
+{"result":[]}
+
+pattern-binding.js:8:14
+Flags: --pretty
+{"result":[]}
+
+pattern-binding.js:10:9
+Flags: --pretty
+{"result":[]}
+
+pattern-binding.js:12:10
+Flags: --pretty
+{"result":[]}
+
+pattern-binding.js:15:4
+Flags: --pretty
+{"result":[{"name":"const","type":""}]}
+
+pattern-object.js:6:5
+Flags: --pretty
+{"result":[]}
+

tests/autocomplete_match/pattern-binding.js

@@ -0,0 +1,17 @@
+declare const x: number;
+
+const foo = "foo"; // Will not be in autocomplete results below.
+
+const e = match (x) {
+  [...const f ]: 0,
+//           ^
+  {...const f }: 0,
+//           ^
+  1 as f : 0,
+//      ^
+  const f : 0,
+//       ^
+
+  c
+// ^
+};

tests/autocomplete_match/pattern-identifier.js

@@ -0,0 +1,8 @@
+declare const x: number;
+
+declare const foo: 1;
+
+const e = match (x) {
+   f
+//  ^
+};

tests/autocomplete_match/pattern-object.js

@@ -0,0 +1,8 @@
+declare const x: number;
+
+const foo = "foo"; // Will not be in autocomplete results below.
+
+const e = match (x) {
+  {f
+//  ^
+};

tests/autocomplete_match/test.sh

@@ -7,3 +7,6 @@
 # shellcheck disable=SC2094
 
 queries_in_file autocomplete "keyword-expression.js" --pretty
+queries_in_file autocomplete "pattern-identifier.js" --pretty
+queries_in_file autocomplete "pattern-binding.js" --pretty
+queries_in_file autocomplete "pattern-object.js" --pretty