fall back to local completions when expr completion misses

analysis/src/CompletionBackEnd.ml

@@ -1410,17 +1410,27 @@ let rec processCompletable ~debug ~full ~scope ~env ~pos ~forHover
         fallbackOrEmpty ~items ())
     | None -> fallbackOrEmpty ())
   | Cexpression {contextPath; prefix; nested} -> (
+    (* Completions for local things like variables in scope, modules in the
+       project, etc. We only add completions when there's a prefix of some sort
+       we can filter on, since we know we're in some sort of context, and
+       therefore don't want to overwhelm the user with completion items. *)
+    let regularCompletions =
+      if prefix = "" then []
+      else
+        prefix
+        |> getComplementaryCompletionsForTypedValue ~opens ~allFiles ~env ~scope
+    in
     match
       contextPath
       |> getCompletionsForContextPath ~full ~opens ~rawOpens ~allFiles ~pos ~env
            ~exact:true ~scope
       |> completionsGetCompletionType ~full
     with
-    | None -> []
+    | None -> regularCompletions
     | Some (typ, env) -> (
       match typ |> TypeUtils.resolveNested ~env ~full ~nested with
-      | None -> []
-      | Some (typ, env, completionContext) -> (
+      | None -> regularCompletions
+      | Some (typ, _env, completionContext) -> (
         (* Wrap the insert text in braces when we're completing the root of a
            JSX prop value. *)
         let wrapInsertTextInBraces =
@@ -1448,12 +1458,6 @@ let rec processCompletable ~debug ~full ~scope ~env ~pos ~forHover
         match (prefix, completionContext) with
         | "", _ -> items
         | _, None ->
-          (* Completions for local things like variables in scope, modules in the project, etc. *)
-          let regularCompletions =
-            prefix
-            |> getComplementaryCompletionsForTypedValue ~opens ~allFiles ~env
-                 ~scope
-          in
           let items =
             if List.length regularCompletions > 0 then
               (* The client will occasionally sort the list of completions alphabetically, disregarding the order
@@ -1538,8 +1542,8 @@ let rec processCompletable ~debug ~full ~scope ~env ~pos ~forHover
            if Utils.startsWith elementName prefix then
              let name = "<" ^ elementName ^ ">" in
              Some
-               (Completion.create name ~kind:(Label name) ~detail:description ~env
-                  ~docstring:[description] ~insertText:elementName
+               (Completion.create name ~kind:(Label name) ~detail:description
+                  ~env ~docstring:[description] ~insertText:elementName
                   ?deprecated:
                     (match deprecated with
                     | true -> Some "true"

analysis/tests/src/CompletionExpressions.res

@@ -177,3 +177,12 @@ let fnTakingCallback = (
 
 // fnTakingCallback(a, b, c, d, e, )
 //                                ^com
+
+let something = {
+  let second = true
+  let second2 = 1
+  ignore(second)
+  ignore(second2)
+  Js.log(s)
+  //      ^com
+}

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

@@ -713,3 +713,37 @@ Completable: Cexpression CArgument Value[fnTakingCallback]($5)
     "insertTextFormat": 2
   }]
 
+Complete src/CompletionExpressions.res 185:10
+posCursor:[185:10] posNoWhite:[185:9] Found expr:[181:2->185:11]
+posCursor:[185:10] posNoWhite:[185:9] Found expr:[182:2->185:11]
+posCursor:[185:10] posNoWhite:[185:9] Found expr:[183:2->185:11]
+posCursor:[185:10] posNoWhite:[185:9] Found expr:[184:2->185:11]
+posCursor:[185:10] posNoWhite:[185:9] Found expr:[185:2->185:11]
+Pexp_apply ...[185:2->185:8] (...[185:9->185:10])
+Completable: Cexpression CArgument Value[Js, log]($0)=s
+[{
+    "label": "second2",
+    "kind": 12,
+    "tags": [],
+    "detail": "int",
+    "documentation": null
+  }, {
+    "label": "second",
+    "kind": 12,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }, {
+    "label": "someBoolVar",
+    "kind": 12,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }, {
+    "label": "s",
+    "kind": 12,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }]
+