Complete tagged template application (#7278)

* WIP tagged template completion

* Ensure debug logging is behind flag

* Include completions of alias

* Turn off evenMoreCompletions

* Add support for tagged template + dot in FrontEnd.

* Revert change to pipe

* Yeah this is the revert pipe thing

* Revert other changes and commit test result

* Remove local execution commands

* Remove debug log

* Change sample

* Add changelog entry

* Split up cases in frontend.

* Add example

CHANGELOG.md

@@ -21,6 +21,7 @@
 - Fix async context checking for module await. https://github.com/rescript-lang/rescript/pull/7271
 - Fix `%external` extension. https://github.com/rescript-lang/rescript/pull/7272
 - Fix issue with type environment for unified ops. https://github.com/rescript-lang/rescript/pull/7277
+- Fix completion for application with tagged template. https://github.com/rescript-lang/rescript/pull/7278
 
 # 12.0.0-alpha.8
 

analysis/src/CompletionFrontEnd.ml

@@ -1127,6 +1127,65 @@ let completionWithParser1 ~currentFile ~debug ~offset ~path ~posCursor
       (* Case foo-> when the parser adds a ghost expression to the rhs
          so the apply expression does not include the cursor *)
       if setPipeResult ~lhs ~id:"" then setFound ()
+    (*
+       A dot completion for a tagged templated application with an expr hole.
+       Example:
+         sh`echo "meh"`.
+    *)
+    | Pexp_apply
+        {
+          funct = {pexp_desc = Pexp_ident {txt = Lident "."; loc = _}};
+          args =
+            [
+              (* sh`echo "meh"` *)
+              (_, ({pexp_desc = Pexp_apply _} as innerExpr));
+              (* recovery inserted node *)
+              (_, {pexp_desc = Pexp_extension ({txt = "rescript.exprhole"}, _)});
+            ];
+        }
+      when Res_parsetree_viewer.is_tagged_template_literal innerExpr ->
+      exprToContextPath innerExpr
+      |> Option.iter (fun cpath ->
+             setResult
+               (Cpath
+                  (CPField
+                     {
+                       contextPath = cpath;
+                       fieldName = "";
+                       posOfDot;
+                       exprLoc = expr.pexp_loc;
+                     }));
+             setFound ())
+    (*
+       A dot completion for a tagged templated application with an ident.
+       Example:
+         sh`echo "meh"`.foo
+    *)
+    | Pexp_apply
+        {
+          funct = {pexp_desc = Pexp_ident {txt = Lident "."; loc = _}};
+          args =
+            [
+              (*  sh`echo "meh"` *)
+              (_, ({pexp_desc = Pexp_apply _} as innerExpr));
+              (* foo *)
+              (_, {pexp_desc = Pexp_ident {txt = Lident fieldName}});
+            ];
+        }
+      when Res_parsetree_viewer.is_tagged_template_literal innerExpr
+           && expr.pexp_loc |> Loc.hasPos ~pos:posBeforeCursor ->
+      exprToContextPath innerExpr
+      |> Option.iter (fun cpath ->
+             setResult
+               (Cpath
+                  (CPField
+                     {
+                       contextPath = cpath;
+                       fieldName;
+                       posOfDot;
+                       exprLoc = expr.pexp_loc;
+                     }));
+             setFound ())
     | _ -> (
       if expr.pexp_loc |> Loc.hasPos ~pos:posNoWhite && !result = None then (
         setFound ();

tests/analysis_tests/tests/src/CompletionTaggedTemplate.res

@@ -0,0 +1,16 @@
+module M = {
+    type t
+
+    let a = (_t:t) => 4
+    let b = (_:t) => "c"
+    let xyz = (_:t, p:int) => p + 1
+}
+
+@module("meh") @taggedTemplate
+external meh: (array<string>, array<string>) => M.t = "default"
+
+// let x = meh`foo`.
+//                  ^com
+
+// let y = meh`bar`.x
+//                   ^com

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

@@ -0,0 +1,80 @@
+Complete src/CompletionTaggedTemplate.res 11:20
+posCursor:[11:20] posNoWhite:[11:19] Found expr:[11:11->0:-1]
+Completable: Cpath Value[meh](Nolabel, Nolabel).""
+Package opens Pervasives.JsxModules.place holder
+ContextPath Value[meh](Nolabel, Nolabel).""
+ContextPath Value[meh](Nolabel, Nolabel)
+ContextPath Value[meh]
+Path meh
+ContextPath Value[meh](Nolabel, Nolabel, Nolabel)->
+ContextPath Value[meh](Nolabel, Nolabel, Nolabel)
+ContextPath Value[meh]
+Path meh
+CPPipe pathFromEnv:M found:true
+Path M.
+[{
+    "label": "->M.xyz",
+    "kind": 12,
+    "tags": [],
+    "detail": "(t, int) => int",
+    "documentation": null,
+    "sortText": "xyz",
+    "insertText": "->M.xyz",
+    "additionalTextEdits": [{
+      "range": {"start": {"line": 11, "character": 19}, "end": {"line": 11, "character": 20}},
+      "newText": ""
+      }]
+  }, {
+    "label": "->M.b",
+    "kind": 12,
+    "tags": [],
+    "detail": "t => string",
+    "documentation": null,
+    "sortText": "b",
+    "insertText": "->M.b",
+    "additionalTextEdits": [{
+      "range": {"start": {"line": 11, "character": 19}, "end": {"line": 11, "character": 20}},
+      "newText": ""
+      }]
+  }, {
+    "label": "->M.a",
+    "kind": 12,
+    "tags": [],
+    "detail": "t => int",
+    "documentation": null,
+    "sortText": "a",
+    "insertText": "->M.a",
+    "additionalTextEdits": [{
+      "range": {"start": {"line": 11, "character": 19}, "end": {"line": 11, "character": 20}},
+      "newText": ""
+      }]
+  }]
+
+Complete src/CompletionTaggedTemplate.res 14:21
+posCursor:[14:21] posNoWhite:[14:20] Found expr:[14:11->14:21]
+Completable: Cpath Value[meh](Nolabel, Nolabel).x
+Package opens Pervasives.JsxModules.place holder
+ContextPath Value[meh](Nolabel, Nolabel).x
+ContextPath Value[meh](Nolabel, Nolabel)
+ContextPath Value[meh]
+Path meh
+ContextPath Value[meh](Nolabel, Nolabel, Nolabel)->x
+ContextPath Value[meh](Nolabel, Nolabel, Nolabel)
+ContextPath Value[meh]
+Path meh
+CPPipe pathFromEnv:M found:true
+Path M.x
+[{
+    "label": "->M.xyz",
+    "kind": 12,
+    "tags": [],
+    "detail": "(t, int) => int",
+    "documentation": null,
+    "sortText": "xyz",
+    "insertText": "->M.xyz",
+    "additionalTextEdits": [{
+      "range": {"start": {"line": 14, "character": 19}, "end": {"line": 14, "character": 20}},
+      "newText": ""
+      }]
+  }]
+