Try completions if path didn't have any results

Author: nojaf

analysis/src/CompletionBackEnd.ml

@@ -1076,34 +1076,7 @@ and getCompletionsForContextPath ~debug ~full ~opens ~rawOpens ~pos ~env ~exact
     | Some (Tpromise (env, typ), _env) ->
       [Completion.create "dummy" ~env ~kind:(Completion.Value typ)]
     | _ -> [])
-  | CPId {path = ["throw"]; completionContext = Value; loc = _} ->
-    let exn_typ = Ctype.newconstr Predef.path_exn [] in
-    let names_from_cmt =
-      let moduleName = env.file.moduleName in
-      match Hashtbl.find_opt full.package.pathsForModule moduleName with
-      | None -> []
-      | Some paths -> (
-        let uri = getUri paths in
-        let cmt_path = getCmtPath ~uri paths in
-        match Shared.tryReadCmt cmt_path with
-        | None -> []
-        | Some infos -> exceptions_from_cmt_infos infos)
-    in
-    let all = names_from_cmt @ predefined_exceptions in
-    all
-    |> List.map (fun (name, hasArgs) ->
-           let insertText =
-             if hasArgs then Printf.sprintf "(%s($0))" name
-             else Printf.sprintf "(%s)" name
-           in
-           let isBuiltin = List.mem (name, hasArgs) predefined_exceptions in
-           let detail =
-             if isBuiltin then "Built-in Exception"
-             else "User-defined Exception"
-           in
-           Completion.create name ~env ~kind:(Completion.Value exn_typ)
-             ~includesSnippets:true ~insertText ~detail)
-  | CPId {path; completionContext; loc} ->
+  | CPId {path; completionContext; loc} -> (
     if Debug.verbose () then print_endline "[ctx_path]--> CPId";
     (* Looks up the type of an identifier.
 
@@ -1141,7 +1114,37 @@ and getCompletionsForContextPath ~debug ~full ~opens ~rawOpens ~pos ~env ~exact
         | _ -> byPath
       else byPath
     in
-    result
+    match (result, path) with
+    | [], [prefix] when Utils.startsWith "throw" prefix ->
+      let exn_typ = Ctype.newconstr Predef.path_exn [] in
+      let names_from_cmt =
+        let moduleName = env.file.moduleName in
+        match Hashtbl.find_opt full.package.pathsForModule moduleName with
+        | None -> []
+        | Some paths -> (
+          let uri = getUri paths in
+          let cmt_path = getCmtPath ~uri paths in
+          match Shared.tryReadCmt cmt_path with
+          | None -> []
+          | Some infos -> exceptions_from_cmt_infos infos)
+      in
+      let all = names_from_cmt @ predefined_exceptions in
+      all
+      |> List.map (fun (name, hasArgs) ->
+             let insertText =
+               if hasArgs then Printf.sprintf "throw(%s($0))" name
+               else Printf.sprintf "throw(%s)" name
+             in
+             let isBuiltin = List.mem (name, hasArgs) predefined_exceptions in
+             let detail =
+               if isBuiltin then "Built-in Exception"
+               else "User-defined Exception"
+             in
+             Completion.create
+               (Printf.sprintf "throw(%s)" name)
+               ~env ~kind:(Completion.Value exn_typ) ~includesSnippets:true
+               ~insertText ~filterText:"throw" ~detail)
+    | _ -> result)
   | CPApply (cp, labels) -> (
     if Debug.verbose () then print_endline "[ctx_path]--> CPApply";
     match

tests/analysis_tests/tests/src/Throw.res

@@ -1,5 +1,5 @@
 exception MyCustomThingToThrow(string)
 exception NoArgsToThrow
 
-// let x = () => throw
-//                    ^com
+// let x = () => thro
+//                   ^com

tests/analysis_tests/tests/src/expected/Throw.res.txt

@@ -1,74 +1,83 @@
-Complete src/Throw.res 3:22
-posCursor:[3:22] posNoWhite:[3:21] Found expr:[3:11->3:22]
-posCursor:[3:22] posNoWhite:[3:21] Found expr:[3:17->3:22]
-Pexp_ident throw:[3:17->3:22]
-Completable: Cpath Value[throw]
+Complete src/Throw.res 3:21
+posCursor:[3:21] posNoWhite:[3:20] Found expr:[3:11->3:21]
+posCursor:[3:21] posNoWhite:[3:20] Found expr:[3:17->3:21]
+Pexp_ident thro:[3:17->3:21]
+Completable: Cpath Value[thro]
 Package opens Stdlib.place holder Pervasives.JsxModules.place holder
 Resolved opens 1 Stdlib
-ContextPath Value[throw]
+ContextPath Value[thro]
+Path thro
 [{
-    "label": "MyCustomThingToThrow",
+    "label": "throw(MyCustomThingToThrow)",
     "kind": 12,
     "tags": [],
     "detail": "User-defined Exception",
     "documentation": null,
-    "insertText": "(MyCustomThingToThrow($0))",
+    "filterText": "throw",
+    "insertText": "throw(MyCustomThingToThrow($0))",
     "insertTextFormat": 2
   }, {
-    "label": "NoArgsToThrow",
+    "label": "throw(NoArgsToThrow)",
     "kind": 12,
     "tags": [],
     "detail": "User-defined Exception",
     "documentation": null,
-    "insertText": "(NoArgsToThrow)",
+    "filterText": "throw",
+    "insertText": "throw(NoArgsToThrow)",
     "insertTextFormat": 2
   }, {
-    "label": "Not_found",
+    "label": "throw(Not_found)",
     "kind": 12,
     "tags": [],
     "detail": "Built-in Exception",
     "documentation": null,
-    "insertText": "(Not_found($0))",
+    "filterText": "throw",
+    "insertText": "throw(Not_found($0))",
     "insertTextFormat": 2
   }, {
-    "label": "Invalid_argument",
+    "label": "throw(Invalid_argument)",
     "kind": 12,
     "tags": [],
     "detail": "Built-in Exception",
     "documentation": null,
-    "insertText": "(Invalid_argument($0))",
+    "filterText": "throw",
+    "insertText": "throw(Invalid_argument($0))",
     "insertTextFormat": 2
   }, {
-    "label": "Assert_failure",
+    "label": "throw(Assert_failure)",
     "kind": 12,
     "tags": [],
     "detail": "Built-in Exception",
     "documentation": null,
-    "insertText": "(Assert_failure($0))",
+    "filterText": "throw",
+    "insertText": "throw(Assert_failure($0))",
     "insertTextFormat": 2
   }, {
-    "label": "Failure",
+    "label": "throw(Failure)",
     "kind": 12,
     "tags": [],
     "detail": "Built-in Exception",
     "documentation": null,
-    "insertText": "(Failure($0))",
+    "filterText": "throw",
+    "insertText": "throw(Failure($0))",
     "insertTextFormat": 2
   }, {
-    "label": "Match_failure",
+    "label": "throw(Match_failure)",
     "kind": 12,
     "tags": [],
     "detail": "Built-in Exception",
     "documentation": null,
-    "insertText": "(Match_failure($0))",
+    "filterText": "throw",
+    "insertText": "throw(Match_failure($0))",
     "insertTextFormat": 2
   }, {
-    "label": "Division_by_zero",
+    "label": "throw(Division_by_zero)",
     "kind": 12,
     "tags": [],
     "detail": "Built-in Exception",
     "documentation": null,
-    "insertText": "(Division_by_zero)",
+    "filterText": "throw",
+    "insertText": "throw(Division_by_zero)",
     "insertTextFormat": 2
   }]