Fix issue where variables bound in switches were not be completed.

The scope mechanism was missing a number of cases for complex patterns, as well as cases in switches.

Author: cristianoc

analysis/src/Completion.ml

@@ -319,13 +319,36 @@ let completionWithParser ~debug ~path ~posCursor ~currentFile ~text =
     scope :=
       !scope |> Scope.addValue ~name:vd.pval_name.txt ~loc:vd.pval_name.loc
   in
+  let rec scopePattern (pat : Parsetree.pattern) =
+    match pat.ppat_desc with
+    | Ppat_any -> ()
+    | Ppat_var {txt; loc} -> scope := !scope |> Scope.addValue ~name:txt ~loc
+    | Ppat_alias (p, asA) ->
+      scopePattern p;
+      scope := !scope |> Scope.addValue ~name:asA.txt ~loc:asA.loc
+    | Ppat_constant _ | Ppat_interval _ -> ()
+    | Ppat_tuple pl -> pl |> List.iter scopePattern
+    | Ppat_construct (_, None) -> ()
+    | Ppat_construct (_, Some p) -> scopePattern p
+    | Ppat_variant (_, None) -> ()
+    | Ppat_variant (_, Some p) -> scopePattern p
+    | Ppat_record (fields, _) ->
+      fields |> List.iter (fun (_, p) -> scopePattern p)
+    | Ppat_array pl -> pl |> List.iter scopePattern
+    | Ppat_or (p1, _) -> scopePattern p1
+    | Ppat_constraint (p, _) -> scopePattern p
+    | Ppat_type _ -> ()
+    | Ppat_lazy p -> scopePattern p
+    | Ppat_unpack {txt; loc} -> scope := !scope |> Scope.addValue ~name:txt ~loc
+    | Ppat_exception p -> scopePattern p
+    | Ppat_extension _ -> ()
+    | Ppat_open (_, p) -> scopePattern p
+  in
+
   let scopeValueBinding (vb : Parsetree.value_binding) =
-    match vb.pvb_pat.ppat_desc with
-    | Ppat_var {txt; loc}
-    | Ppat_constraint ({ppat_desc = Ppat_var {txt; loc}}, _) ->
-      scope := !scope |> Scope.addValue ~name:txt ~loc
-    | _ -> ()
+    scopePattern vb.pvb_pat
   in
+
   let scopeTypeKind (tk : Parsetree.type_kind) =
     match tk with
     | Ptype_variant constrDecls ->
@@ -355,6 +378,12 @@ let completionWithParser ~debug ~path ~posCursor ~currentFile ~text =
       !scope |> Scope.addModule ~name:md.pmd_name.txt ~loc:md.pmd_name.loc
   in
 
+  let case (iterator : Ast_iterator.iterator) (case : Parsetree.case) =
+    let oldScope = !scope in
+    scopePattern case.pc_lhs;
+    Ast_iterator.default_iterator.case iterator case;
+    scope := oldScope
+  in
   let structure (iterator : Ast_iterator.iterator)
       (structure : Parsetree.structure) =
     let oldScope = !scope in
@@ -712,6 +741,7 @@ let completionWithParser ~debug ~path ~posCursor ~currentFile ~text =
     {
       Ast_iterator.default_iterator with
       attribute;
+      case;
       expr;
       module_expr;
       module_type;

analysis/tests/src/Completion.res

@@ -232,3 +232,11 @@ module FAO = {
 
 // FAO.forAutoObject["forAutoLabel"].forAuto->ForAuto.a
 //                                                     ^com
+
+let someR = Some(r)
+let _ = switch someR {
+| Some(_z) => 1
+// + _z.
+//      ^com
+| _ => 3
+}

analysis/tests/src/expected/Completion.res.txt

@@ -827,6 +827,11 @@ DocumentSymbol tests/src/Completion.res
         "name": "forAutoObject",
         "kind": 13,
         "location": {"uri": "Completion.res", "range": {"start": {"line": 220, "character": 2}, "end": {"line": 220, "character": 68}}}
+},
+{
+        "name": "someR",
+        "kind": 13,
+        "location": {"uri": "Completion.res", "range": {"start": {"line": 235, "character": 0}, "end": {"line": 235, "character": 19}}}
 }
 ]
 
@@ -1228,8 +1233,8 @@ Completable: Cpath Value[FAO, forAutoObject][""]
   }]
 
 Complete tests/src/Completion.res 226:37
-posCursor:[226:37] posNoWhite:[226:36] Found expr:[226:3->235:0]
-Pexp_field [226:3->226:36] _:[235:0->235:0]
+posCursor:[226:37] posNoWhite:[226:36] Found expr:[226:3->235:3]
+Pexp_field [226:3->226:36] _:[235:0->235:3]
 Completable: Cpath Value[FAO, forAutoObject]["forAutoLabel"].""
 [{
     "label": "forAuto",
@@ -1281,3 +1286,25 @@ Completable: Cpath Value[ForAuto, a]
     "documentation": null
   }]
 
+Complete tests/src/Completion.res 238:8
+posCursor:[238:8] posNoWhite:[238:7] Found expr:[236:8->241:1]
+posCursor:[238:8] posNoWhite:[238:7] Found expr:[237:14->240:8]
+posCursor:[238:8] posNoWhite:[238:7] Found expr:[237:14->240:1]
+Pexp_apply ...[238:3->238:4] (...[237:14->237:15], ...[238:5->240:1])
+posCursor:[238:8] posNoWhite:[238:7] Found expr:[238:5->240:1]
+Pexp_field [238:5->238:7] _:[240:0->240:1]
+Completable: Cpath Value[_z].""
+[{
+    "label": "x",
+    "kind": 5,
+    "tags": [],
+    "detail": "x: int\n\ntype r = {x: int, y: string}",
+    "documentation": null
+  }, {
+    "label": "y",
+    "kind": 5,
+    "tags": [],
+    "detail": "y: string\n\ntype r = {x: int, y: string}",
+    "documentation": null
+  }]
+