Implement type command (#19944)

* Implement type command

- this will be mapped to textDocument/typeDefinition in LSP protocol. It will be
very useful for `nim` in particular because typically most of the time the type
is inferred.

* Update nimsuggest/nimsuggest.nim

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>

nimsuggest/nimsuggest.nim

@@ -457,6 +457,7 @@ proc execCmd(cmd: string; graph: ModuleGraph; cachedMsgs: CachedMsgs) =
   of "globalsymbols": conf.ideCmd = ideGlobalSymbols
   of "chkfile": conf.ideCmd = ideChkFile
   of "recompile": conf.ideCmd = ideRecompile
+  of "type": conf.ideCmd = ideType
   else: err()
   var dirtyfile = ""
   var orig = ""
@@ -786,7 +787,7 @@ proc executeNoHooksV3(cmd: IdeCmd, file: AbsoluteFile, dirtyfile: AbsoluteFile,
     graph.unmarkAllDirty()
 
   # these commands require partially compiled project
-  elif cmd in {ideSug, ideOutline, ideHighlight, ideDef, ideChkFile} and
+  elif cmd in {ideSug, ideOutline, ideHighlight, ideDef, ideChkFile, ideType} and
        (graph.needsCompilation(fileIndex) or cmd == ideSug):
     # for ideSug use v2 implementation
     if cmd == ideSug:
@@ -802,6 +803,15 @@ proc executeNoHooksV3(cmd: IdeCmd, file: AbsoluteFile, dirtyfile: AbsoluteFile,
     let (sym, info) = graph.findSymData(file, line, col)
     if sym != nil:
       graph.suggestResult(sym, sym.info)
+  of ideType:
+    let (sym, _) = graph.findSymData(file, line, col)
+    if sym != nil:
+      let typeSym = sym.typ.sym
+      if typeSym != nil:
+        graph.suggestResult(typeSym, typeSym.info, ideType)
+      elif sym.typ.len != 0:
+        let genericType = sym.typ[0].sym
+        graph.suggestResult(genericType, genericType.info, ideType)
   of ideUse, ideDus:
     let symbol = graph.findSymData(file, line, col).sym
     if symbol != nil:

nimsuggest/tester.nim

@@ -282,7 +282,7 @@ proc runEpcTest(filename: string): int =
         socket.sendEpcStr(req)
         let sx = parseSexp(socket.recvEpc())
         if not req.startsWith("mod "):
-          let answer = sexpToAnswer(sx)
+          let answer = if sx[2].kind == SNil: "" else: sexpToAnswer(sx)
           doReport(filename, answer, resp, report)
 
     socket.sendEpcStr "return arg"

nimsuggest/tests/tv3_typeDefinition.nim

@@ -0,0 +1,32 @@
+# tests v3
+
+type
+  Foo* = ref object of RootObj
+    bar*: string
+
+proc test(ff: Foo) =
+  echo f#[!]#f.bar
+
+type
+  Fo#[!]#o2* = ref object of RootObj
+
+type
+  FooGeneric[T] = ref object of RootObj
+    bar*: T
+
+let fooGeneric = FooGeneric[string]()
+echo fo#[!]#oGeneric.bar
+
+# bad type
+echo unde#[!]#fined
+
+discard """
+$nimsuggest --v3 --tester $file
+>type $1
+type	skType	tv3_typeDefinition.Foo	Foo	$file	4	2	""	100
+>type $2
+type	skType	tv3_typeDefinition.Foo2	Foo2	$file	11	2	""	100
+>type $3
+type	skType	tv3_typeDefinition.FooGeneric	FooGeneric	$file	14	2	""	100
+>type $4
+"""