Show variant constructor's inline record types on hover (#7519)

* Show variant inline record type on hover

* Show variant constructor type information below type on hover

* Refactor Hover.newHover

* Add analysis tests

* Add CHANGELOG entry

Author: mediremi

CHANGELOG.md

@@ -17,6 +17,7 @@
 - Add `RegExp.flags`. https://github.com/rescript-lang/rescript/pull/7461
 - Add `Array.findLast`, `Array.findLastWithIndex`, `Array.findLastIndex`, `Array.findLastIndexWithIndex` and `Array.findLastIndexOpt`. https://github.com/rescript-lang/rescript/pull/7503
 - Add `options` argument to `Console.dir`. https://github.com/rescript-lang/rescript/pull/7504
+- Show variant constructor's inline record types on hover. https://github.com/rescript-lang/rescript/pull/7519
 
 #### :bug: Bug fix
 

analysis/src/Hover.ml

@@ -137,13 +137,21 @@ let expandTypes ~file ~package ~supportsMarkdownLinks typ =
       `Default )
 
 (* Produces a hover with relevant types expanded in the main type being hovered. *)
-let hoverWithExpandedTypes ~file ~package ~supportsMarkdownLinks typ =
-  let typeString = Markdown.codeBlock (typ |> Shared.typeToString) in
+let hoverWithExpandedTypes ~file ~package ~supportsMarkdownLinks ?constructor
+    typ =
   let expandedTypes, expansionType =
     expandTypes ~file ~package ~supportsMarkdownLinks typ
   in
   match expansionType with
-  | `Default -> typeString :: expandedTypes |> String.concat "\n"
+  | `Default ->
+    let typeString = Shared.typeToString typ in
+    let typeString =
+      match constructor with
+      | Some constructor ->
+        typeString ^ "\n" ^ CompletionBackEnd.showConstructor constructor
+      | None -> typeString
+    in
+    Markdown.codeBlock typeString :: expandedTypes |> String.concat "\n"
   | `InlineType -> expandedTypes |> String.concat "\n"
 
 (* Leverages autocomplete functionality to produce a hover for a position. This
@@ -256,33 +264,22 @@ let newHover ~full:{file; package} ~supportsMarkdownLinks locItem =
          | Const_int64 _ -> "int64"
          | Const_bigint _ -> "bigint"))
   | Typed (_, t, locKind) ->
-    let fromType ~docstring typ =
-      ( hoverWithExpandedTypes ~file ~package ~supportsMarkdownLinks typ,
-        docstring )
+    let fromType ?constructor typ =
+      hoverWithExpandedTypes ~file ~package ~supportsMarkdownLinks ?constructor
+        typ
     in
     let parts =
       match References.definedForLoc ~file ~package locKind with
       | None ->
-        let typeString, docstring = t |> fromType ~docstring:[] in
-        typeString :: docstring
+        let typeString = t |> fromType in
+        [typeString]
       | Some (docstring, res) -> (
         match res with
-        | `Declared ->
-          let typeString, docstring = t |> fromType ~docstring in
+        | `Declared | `Field ->
+          let typeString = t |> fromType in
           typeString :: docstring
-        | `Constructor {cname = {txt}; args; docstring} ->
-          let typeString, docstring = t |> fromType ~docstring in
-          let argsString =
-            match args with
-            | InlineRecord _ | Args [] -> ""
-            | Args args ->
-              args
-              |> List.map (fun (t, _) -> Shared.typeToString t)
-              |> String.concat ", " |> Printf.sprintf "(%s)"
-          in
-          typeString :: Markdown.codeBlock (txt ^ argsString) :: docstring
-        | `Field ->
-          let typeString, docstring = t |> fromType ~docstring in
-          typeString :: docstring)
+        | `Constructor constructor ->
+          let typeString = t |> fromType ~constructor in
+          typeString :: constructor.docstring)
     in
     Some (String.concat Markdown.divider parts)

tests/analysis_tests/tests/src/Hover.res

@@ -254,6 +254,14 @@ type variant = | /** Cool variant! */ CoolVariant | /** Other cool variant */ Ot
 let coolVariant = CoolVariant
 //                  ^hov
 
+type payloadVariants = InlineRecord({field1: int, field2: bool}) | Args(int, bool)
+
+let payloadVariant = InlineRecord({field1: 1, field2: true})
+//                    ^hov
+
+let payloadVariant2 = Args(1, true)
+//                     ^hov
+
 // Hover on unsaved
 // let fff = "hello"; fff
 //                     ^hov

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

@@ -301,12 +301,18 @@ Hover src/Hover.res 248:19
 {"contents": {"kind": "markdown", "value": "```rescript\nbool\n```\n---\n Mighty fine field here. "}}
 
 Hover src/Hover.res 253:20
-{"contents": {"kind": "markdown", "value": "```rescript\nvariant\n```\n\n---\n\n```\n \n```\n```rescript\ntype variant = CoolVariant | OtherCoolVariant\n```\nGo to: [Type definition](command:rescript-vscode.go_to_location?%5B%22Hover.res%22%2C251%2C0%5D)\n\n---\n```rescript\nCoolVariant\n```\n---\n Cool variant! "}}
+{"contents": {"kind": "markdown", "value": "```rescript\nvariant\nCoolVariant\n```\n\n---\n\n```\n \n```\n```rescript\ntype variant = CoolVariant | OtherCoolVariant\n```\nGo to: [Type definition](command:rescript-vscode.go_to_location?%5B%22Hover.res%22%2C251%2C0%5D)\n\n---\n Cool variant! "}}
 
-Hover src/Hover.res 257:23
+Hover src/Hover.res 258:22
+{"contents": {"kind": "markdown", "value": "```rescript\npayloadVariants\nInlineRecord({field1: int, field2: bool})\n```\n\n---\n\n```\n \n```\n```rescript\ntype payloadVariants =\n  | InlineRecord({field1: int, field2: bool})\n  | Args(int, bool)\n```\nGo to: [Type definition](command:rescript-vscode.go_to_location?%5B%22Hover.res%22%2C256%2C0%5D)\n"}}
+
+Hover src/Hover.res 261:23
+{"contents": {"kind": "markdown", "value": "```rescript\npayloadVariants\nArgs(int, bool)\n```\n\n---\n\n```\n \n```\n```rescript\ntype payloadVariants =\n  | InlineRecord({field1: int, field2: bool})\n  | Args(int, bool)\n```\nGo to: [Type definition](command:rescript-vscode.go_to_location?%5B%22Hover.res%22%2C256%2C0%5D)\n"}}
+
+Hover src/Hover.res 265:23
 Nothing at that position. Now trying to use completion.
-posCursor:[257:23] posNoWhite:[257:22] Found expr:[257:22->257:25]
-Pexp_ident fff:[257:22->257:25]
+posCursor:[265:23] posNoWhite:[265:22] Found expr:[265:22->265:25]
+Pexp_ident fff:[265:22->265:25]
 Completable: Cpath Value[fff]
 Package opens Stdlib.place holder Pervasives.JsxModules.place holder
 Resolved opens 1 Stdlib
@@ -317,10 +323,10 @@ Resolved opens 1 Stdlib
 ContextPath string
 {"contents": {"kind": "markdown", "value": "```rescript\nstring\n```"}}
 
-Hover src/Hover.res 260:33
+Hover src/Hover.res 268:33
 Nothing at that position. Now trying to use completion.
-posCursor:[260:33] posNoWhite:[260:32] Found expr:[260:31->260:40]
-Pexp_ident someField:[260:31->260:40]
+posCursor:[268:33] posNoWhite:[268:32] Found expr:[268:31->268:40]
+Pexp_ident someField:[268:31->268:40]
 Completable: Cpath Value[someField]
 Package opens Stdlib.place holder Pervasives.JsxModules.place holder
 Resolved opens 1 Stdlib
@@ -333,9 +339,9 @@ ContextPath Value[x]
 Path x
 {"contents": {"kind": "markdown", "value": "```rescript\nbool\n```"}}
 
-Hover src/Hover.res 263:8
+Hover src/Hover.res 271:8
 {"contents": {"kind": "markdown", "value": "\n [`Belt.Array`]()\n\n  **mutable array**: Utilities functions\n\n```rescript\nmodule Array: {\n  module Id\n  module Array\n  module SortArray\n  module MutableQueue\n  module MutableStack\n  module List\n  module Range\n  module Set\n  module Map\n  module MutableSet\n  module MutableMap\n  module HashSet\n  module HashMap\n  module Option\n  module Result\n  module Int\n  module Float\n}\n```"}}
 
-Hover src/Hover.res 266:6
+Hover src/Hover.res 274:6
 {"contents": {"kind": "markdown", "value": "```rescript\ntype aliased = variant\n```\n\n---\n\n```\n \n```\n```rescript\ntype variant = CoolVariant | OtherCoolVariant\n```\nGo to: [Type definition](command:rescript-vscode.go_to_location?%5B%22Hover.res%22%2C251%2C0%5D)\n"}}