nixd: support textDocument/rename, textDocument/prepareRename (#405)

Fixes: #255

libnixf/include/nixf/Sema/VariableLookup.h

@@ -79,6 +79,7 @@ class VariableLookupAnalysis {
     Undefined,
     FromWith,
     Defined,
+    NoSuchVar,
   };
 
   struct LookupResult {
@@ -129,6 +130,8 @@ class VariableLookupAnalysis {
 
   /// \brief Query the which name/with binds to specific varaible.
   [[nodiscard]] LookupResult query(const ExprVar &Var) const {
+    if (!Results.contains(&Var))
+      return {.Kind = LookupResultKind::NoSuchVar};
     return Results.at(&Var);
   }
 

nixd/include/nixd/Controller/Controller.h

@@ -92,6 +92,12 @@ class Controller : public lspserver::LSPServer {
                           std::optional<int64_t> Version,
                           const std::vector<nixf::Diagnostic> &Diagnostics);
 
+  void onRename(const lspserver::RenameParams &Params,
+                lspserver::Callback<lspserver::WorkspaceEdit> Reply);
+
+  void onPrepareRename(const lspserver::TextDocumentPositionParams &Params,
+                       lspserver::Callback<lspserver::Range> Reply);
+
 public:
   Controller(std::unique_ptr<lspserver::InboundPort> In,
              std::unique_ptr<lspserver::OutboundPort> Out);

nixd/lib/Controller/Definition.cpp

@@ -127,11 +127,14 @@ nixd::findDefinition(const Node &N, const ParentMapAnalysis &PMA,
   assert(Var->kind() == Node::NK_ExprVar);
   LookupResult Result = VLA.query(static_cast<const ExprVar &>(*Var));
 
-  assert(Result.Def);
-
   if (Result.Kind == ResultKind::Undefined)
     return error("this varaible is undefined");
 
+  if (Result.Kind == ResultKind::NoSuchVar)
+    return error("this varaible is not used in var lookup (duplicated attr?)");
+
+  assert(Result.Def);
+
   if (Result.Def->isBuiltin())
     return error("this is a builtin variable");
 

nixd/lib/Controller/LifeTime.cpp

@@ -39,7 +39,11 @@ void Controller::
        {"definitionProvider", true},
        {"referencesProvider", true},
        {"documentHighlightProvider", true},
-       {"hoverProvider", true}},
+       {"hoverProvider", true},
+       {"renameProvider",
+        Object{
+            {"prepareProvider", true},
+        }}},
   };
 
   Object Result{{

nixd/lib/Controller/Rename.cpp

@@ -0,0 +1,98 @@
+/// \file
+/// \brief This implements [Rename].
+/// [Rename]:
+/// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_rename
+
+#include "Convert.h"
+#include "Definition.h"
+
+#include "lspserver/Protocol.h"
+#include "nixd/Controller/Controller.h"
+
+#include <boost/asio/post.hpp>
+
+using namespace lspserver;
+using namespace nixd;
+using namespace llvm;
+using namespace nixf;
+
+namespace {
+llvm::Expected<WorkspaceEdit> rename(const nixf::Node &Desc,
+                                     const std::string &NewText,
+                                     const ParentMapAnalysis &PMA,
+                                     const VariableLookupAnalysis &VLA,
+                                     const URIForFile &URI) {
+  using lspserver::TextEdit;
+  // Find "definition"
+  auto Def = findDefinition(Desc, PMA, VLA);
+  if (!Def)
+    return Def.takeError();
+
+  std::vector<TextEdit> Edits;
+
+  for (const auto *Use : Def->uses()) {
+    Edits.emplace_back(TextEdit{
+        .range = toLSPRange(Use->range()),
+        .newText = NewText,
+    });
+  }
+
+  Edits.emplace_back(TextEdit{
+      .range = toLSPRange(Def->syntax()->range()),
+      .newText = NewText,
+  });
+  WorkspaceEdit WE;
+  WE.changes = std::map<std::string, std::vector<TextEdit>>{
+      {URI.uri(), std::move(Edits)}};
+  return WE;
+}
+} // namespace
+
+void Controller::onRename(const RenameParams &Params,
+                          Callback<WorkspaceEdit> Reply) {
+  auto Action = [Reply = std::move(Reply), URI = Params.textDocument.uri,
+                 Pos = toNixfPosition(Params.position),
+                 NewText = Params.newName, this]() mutable {
+    std::string File(URI.file());
+    if (std::shared_ptr<NixTU> TU = getTU(File, Reply)) [[likely]] {
+      if (std::shared_ptr<nixf::Node> AST = getAST(*TU, Reply)) [[likely]] {
+        const nixf::Node *Desc = AST->descend({Pos, Pos});
+        if (!Desc) {
+          Reply(error("cannot find corresponding node on given position"));
+          return;
+        }
+        Reply(rename(*Desc, NewText, *TU->parentMap(), *TU->variableLookup(),
+                     URI));
+        return;
+      }
+    }
+  };
+  boost::asio::post(Pool, std::move(Action));
+}
+
+void Controller::onPrepareRename(
+    const lspserver::TextDocumentPositionParams &Params,
+    Callback<lspserver::Range> Reply) {
+  auto Action = [Reply = std::move(Reply), URI = Params.textDocument.uri,
+                 Pos = toNixfPosition(Params.position), this]() mutable {
+    std::string File(URI.file());
+    if (std::shared_ptr<NixTU> TU = getTU(File, Reply)) [[likely]] {
+      if (std::shared_ptr<nixf::Node> AST = getAST(*TU, Reply)) [[likely]] {
+        const nixf::Node *Desc = AST->descend({Pos, Pos});
+        if (!Desc) {
+          Reply(error("cannot find corresponding node on given position"));
+          return;
+        }
+        llvm::Expected<WorkspaceEdit> Exp =
+            rename(*Desc, "", *TU->parentMap(), *TU->variableLookup(), URI);
+        if (Exp) {
+          Reply(toLSPRange(Desc->range()));
+          return;
+        }
+        Reply(Exp.takeError());
+        return;
+      }
+    }
+  };
+  boost::asio::post(Pool, std::move(Action));
+}

nixd/lib/Controller/Support.cpp

@@ -132,6 +132,9 @@ Controller::Controller(std::unique_ptr<lspserver::InboundPort> In,
   Registry.addMethod("textDocument/codeAction", this,
                      &Controller::onCodeAction);
   Registry.addMethod("textDocument/hover", this, &Controller::onHover);
+  Registry.addMethod("textDocument/rename", this, &Controller::onRename);
+  Registry.addMethod("textDocument/prepareRename", this,
+                     &Controller::onPrepareRename);
 }
 
 } // namespace nixd

nixd/meson.build

@@ -14,6 +14,7 @@ libnixd_lib = library(
     'lib/Controller/Hover.cpp',
     'lib/Controller/LifeTime.cpp',
     'lib/Controller/NixTU.cpp',
+    'lib/Controller/Rename.cpp',
     'lib/Controller/Support.cpp',
     'lib/Controller/TextDocumentSync.cpp',
     'lib/Eval/EvalProvider.cpp',

nixd/tools/nixd/test/initialize.md

@@ -36,6 +36,9 @@ CHECK-NEXT:       "definitionProvider": true,
 CHECK-NEXT:       "documentHighlightProvider": true,
 CHECK-NEXT:       "hoverProvider": true,
 CHECK-NEXT:       "referencesProvider": true,
+CHECK-NEXT:       "renameProvider": {
+CHECK-NEXT:         "prepareProvider": true
+CHECK-NEXT:       },
 CHECK-NEXT:       "textDocumentSync": {
 CHECK-NEXT:         "change": 2,
 CHECK-NEXT:         "openClose": true,

nixd/tools/nixd/test/rename-duplicated.md

@@ -0,0 +1,72 @@
+# RUN: nixd --lit-test < %s | FileCheck %s
+
+// https://github.com/nix-community/nixd/issues/255
+
+<-- initialize(0)
+
+```json
+{
+   "jsonrpc":"2.0",
+   "id":0,
+   "method":"initialize",
+   "params":{
+      "processId":123,
+      "rootPath":"",
+      "capabilities":{
+      },
+      "trace":"off"
+   }
+}
+```
+
+
+<-- textDocument/didOpen
+
+```json
+{
+   "jsonrpc":"2.0",
+   "method":"textDocument/didOpen",
+   "params":{
+      "textDocument":{
+         "uri":"file:///basic.nix",
+         "languageId":"nix",
+         "version":1,
+         "text":"rec { bar = 1; a = 1; a = bar; b = a; }"
+      }
+   }
+}
+```
+
+<-- textDocument/rename(2)
+
+
+```json
+{
+   "jsonrpc":"2.0",
+   "id":2,
+   "method":"textDocument/rename",
+   "params":{
+      "textDocument":{
+         "uri":"file:///basic.nix"
+      },
+      "position":{
+        "line": 0,
+        "character":28
+      },
+      "newName": "b"
+   }
+}
+```
+
+```
+     CHECK: "error": {
+CHECK-NEXT:   "code": -32001,
+CHECK-NEXT:   "message": "this varaible is not used in var lookup (duplicated attr?)"
+CHECK-NEXT: },
+CHECK-NEXT: "id": 2,
+CHECK-NEXT: "jsonrpc": "2.0"
+```
+
+```json
+{"jsonrpc":"2.0","method":"exit"}
+```

nixd/tools/nixd/test/rename-issue-255-1.md

@@ -0,0 +1,97 @@
+# RUN: nixd --lit-test < %s | FileCheck %s
+
+// https://github.com/nix-community/nixd/issues/255
+
+<-- initialize(0)
+
+```json
+{
+   "jsonrpc":"2.0",
+   "id":0,
+   "method":"initialize",
+   "params":{
+      "processId":123,
+      "rootPath":"",
+      "capabilities":{
+      },
+      "trace":"off"
+   }
+}
+```
+
+
+<-- textDocument/didOpen
+
+```json
+{
+   "jsonrpc":"2.0",
+   "method":"textDocument/didOpen",
+   "params":{
+      "textDocument":{
+         "uri":"file:///basic.nix",
+         "languageId":"nix",
+         "version":1,
+         "text":"{a ? 1}: { x = a; }"
+      }
+   }
+}
+```
+
+<-- textDocument/rename(2)
+
+
+```json
+{
+   "jsonrpc":"2.0",
+   "id":2,
+   "method":"textDocument/rename",
+   "params":{
+      "textDocument":{
+         "uri":"file:///basic.nix"
+      },
+      "position":{
+        "line": 0,
+        "character":1
+      },
+      "newName": "b"
+   }
+}
+```
+
+```
+     CHECK: "id": 2,
+CHECK-NEXT: "jsonrpc": "2.0",
+CHECK-NEXT: "result": {
+CHECK-NEXT:   "changes": {
+CHECK-NEXT:     "file:///basic.nix": [
+CHECK-NEXT:       {
+CHECK-NEXT:         "newText": "b",
+CHECK-NEXT:         "range": {
+CHECK-NEXT:           "end": {
+CHECK-NEXT:             "character": 16,
+CHECK-NEXT:             "line": 0
+CHECK-NEXT:           },
+CHECK-NEXT:           "start": {
+CHECK-NEXT:             "character": 15,
+CHECK-NEXT:             "line": 0
+CHECK-NEXT:           }
+CHECK-NEXT:         }
+CHECK-NEXT:       },
+CHECK-NEXT:       {
+CHECK-NEXT:         "newText": "b",
+CHECK-NEXT:         "range": {
+CHECK-NEXT:           "end": {
+CHECK-NEXT:             "character": 2,
+CHECK-NEXT:             "line": 0
+CHECK-NEXT:           },
+CHECK-NEXT:           "start": {
+CHECK-NEXT:             "character": 1,
+CHECK-NEXT:             "line": 0
+CHECK-NEXT:           }
+CHECK-NEXT:         }
+CHECK-NEXT:       }
+```
+
+```json
+{"jsonrpc":"2.0","method":"exit"}
+```