Do not expand type t in patterns

CHANGELOG.md

@@ -24,6 +24,7 @@
 - Make JSX completion work for `make` functions of type `React.component<props>`, like what you get when using `React.lazy_`. https://github.com/rescript-lang/rescript-vscode/pull/966
 - Hover: print signature above docstrings. https://github.com/rescript-lang/rescript-vscode/pull/969
 - Adjust function template snippet return. https://github.com/rescript-lang/rescript-vscode/pull/985
+- Don't expand `type t` maker functions in patterns. https://github.com/rescript-lang/rescript-vscode/pull/986
 
 #### :rocket: New Feature
 

analysis/src/CompletionBackEnd.ml

@@ -1355,8 +1355,9 @@ let rec completeTypedValue ?(typeArgContext : typeArgContext option) ~rawOpens
   let printConstructorArgs = printConstructorArgs ~mode in
   let create = Completion.create ?typeArgContext in
   match t with
-  | TtypeT {env; path} ->
-    if Debug.verbose () then print_endline "[complete_typed_value]--> TtypeT";
+  | TtypeT {env; path} when mode = Expression ->
+    if Debug.verbose () then
+      print_endline "[complete_typed_value]--> TtypeT (Expression)";
     (* Find all values in the module with type t *)
     let valueWithTypeT t =
       match t.Types.desc with
@@ -1445,6 +1446,22 @@ let rec completeTypedValue ?(typeArgContext : typeArgContext option) ~rawOpens
       create "false" ~kind:(Label "bool") ~env;
     ]
     |> filterItems ~prefix
+  | TtypeT {env; path} ->
+    if Debug.verbose () then
+      print_endline "[complete_typed_value]--> TtypeT (Pattern)";
+    (* This is in patterns. Emit an alias/binding with the module name as a value name. *)
+    if prefix <> "" then []
+    else
+      let moduleName =
+        match path |> Utils.expandPath with
+        | _t :: moduleName :: _rest -> String.uncapitalize_ascii moduleName
+        | _ -> "value"
+      in
+      [
+        create moduleName ~kind:(Label moduleName) ~env
+          ~insertText:("${0:" ^ moduleName ^ "}")
+          ~includesSnippets:true;
+      ]
   | Tvariant {env; constructors; variantDecl; variantName} ->
     if Debug.verbose () then print_endline "[complete_typed_value]--> Tvariant";
     constructors

analysis/tests/src/CompletionTypeT.res

@@ -0,0 +1,9 @@
+let date = Some(Js.Date.make())
+
+type withDate = {date: Js.Date.t}
+
+// let x = switch date { | }
+//                        ^com
+
+// let x: withDate = {date: }
+//                         ^com

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

@@ -0,0 +1,112 @@
+Complete src/CompletionTypeT.res 4:26
+XXX Not found!
+Completable: Cpattern Value[date]
+Package opens Pervasives.JsxModules.place holder
+Resolved opens 1 pervasives
+ContextPath Value[date]
+Path date
+[{
+    "label": "None",
+    "kind": 12,
+    "tags": [],
+    "detail": "Js.Date.t",
+    "documentation": null
+  }, {
+    "label": "Some(_)",
+    "kind": 12,
+    "tags": [],
+    "detail": "Js.Date.t",
+    "documentation": null,
+    "insertText": "Some(${1:_})",
+    "insertTextFormat": 2
+  }, {
+    "label": "Some(date)",
+    "kind": 4,
+    "tags": [],
+    "detail": "date",
+    "documentation": null,
+    "insertText": "Some(${0:date})",
+    "insertTextFormat": 2
+  }]
+
+Complete src/CompletionTypeT.res 7:27
+XXX Not found!
+Completable: Cexpression Type[withDate]->recordField(date)
+Package opens Pervasives.JsxModules.place holder
+Resolved opens 1 pervasives
+ContextPath Type[withDate]
+Path withDate
+[{
+    "label": "Js.Date.makeWithYMD()",
+    "kind": 12,
+    "tags": [],
+    "detail": "(~year: float, ~month: float, ~date: float, unit) => t",
+    "documentation": null,
+    "insertText": "Js.Date.makeWithYMD($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.makeWithYMDHM()",
+    "kind": 12,
+    "tags": [],
+    "detail": "(\n  ~year: float,\n  ~month: float,\n  ~date: float,\n  ~hours: float,\n  ~minutes: float,\n  unit,\n) => t",
+    "documentation": null,
+    "insertText": "Js.Date.makeWithYMDHM($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.make()",
+    "kind": 12,
+    "tags": [],
+    "detail": "unit => t",
+    "documentation": null,
+    "insertText": "Js.Date.make($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.fromString()",
+    "kind": 12,
+    "tags": [],
+    "detail": "string => t",
+    "documentation": null,
+    "insertText": "Js.Date.fromString($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.fromFloat()",
+    "kind": 12,
+    "tags": [],
+    "detail": "float => t",
+    "documentation": null,
+    "insertText": "Js.Date.fromFloat($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.parse()",
+    "kind": 12,
+    "tags": [],
+    "detail": "string => t",
+    "documentation": null,
+    "insertText": "Js.Date.parse($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.makeWithYM()",
+    "kind": 12,
+    "tags": [],
+    "detail": "(~year: float, ~month: float, unit) => t",
+    "documentation": null,
+    "insertText": "Js.Date.makeWithYM($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.makeWithYMDHMS()",
+    "kind": 12,
+    "tags": [],
+    "detail": "(\n  ~year: float,\n  ~month: float,\n  ~date: float,\n  ~hours: float,\n  ~minutes: float,\n  ~seconds: float,\n  unit,\n) => t",
+    "documentation": null,
+    "insertText": "Js.Date.makeWithYMDHMS($0)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Js.Date.makeWithYMDH()",
+    "kind": 12,
+    "tags": [],
+    "detail": "(\n  ~year: float,\n  ~month: float,\n  ~date: float,\n  ~hours: float,\n  unit,\n) => t",
+    "documentation": null,
+    "insertText": "Js.Date.makeWithYMDH($0)",
+    "insertTextFormat": 2
+  }]
+