[clangd] Expose Code Completion score to the client

[kbobyrev]

Summary

Make it possible for the client to adjust the ranking by using the score Clangd
calculates for the completion items.

[kbobyrev]

Replace actual scores with regex for stability.

[sammccall]

clang-tools-extra/clangd/Protocol.h

1100

/// This is a clangd extension.

clang-tools-extra/clangd/test/completion-auto-trigger.test

27

let's not include the value (note we don't in sortText either, which contains the encoded float)

Use {{.*}}

[kbobyrev]

Replace one instance of hardcoded score missed in the previous update.

[sammccall]

clang-tools-extra/clangd/test/protocol.test

42

oops, raced with you...

you missed some :-)
also I'd just use {{.*}} for readability, up to you though

[kbobyrev]

Make a note that score is Clangd extension.

clang-tools-extra/clangd/CodeComplete.cpp

CompletionItem CodeCompletion::render(const CodeCompleteOptions &Opts) const {
   // FIXME(kadircet): Do not even fill insertText after making sure textEdit is
   // compatible with most of the editors.
   LSP.insertText = LSP.textEdit->newText;
   LSP.insertTextFormat = Opts.EnableSnippets ? InsertTextFormat::Snippet
                                              : InsertTextFormat::PlainText;
   if (InsertInclude && InsertInclude->Insertion)
     LSP.additionalTextEdits.push_back(*InsertInclude->Insertion);
 
+  LSP.score = Score.ExcludingName;
+
   return LSP;
 }
 
 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const CodeCompletion &C) {
   // For now just lean on CompletionItem.
   return OS << C.render(CodeCompleteOptions());
 }
 

clang-tools-extra/clangd/Protocol.h

struct CompletionItem {
   /// An optional array of additional text edits that are applied when selecting
   /// this completion. Edits must not overlap with the main edit nor with
   /// themselves.
   std::vector<TextEdit> additionalTextEdits;
 
   /// Indicates if this item is deprecated.
   bool deprecated = false;
 
+  /// The score that Clangd calculates to rank completion items. This score can
+  /// be used to adjust the ranking on the client side.
+  /// NOTE: This excludes fuzzy matching score which is typically calculated on
+  /// the client side.
+  float score = 0.f;
+
   // TODO(krasimir): The following optional fields defined by the language
   // server protocol are unsupported:
   //
   // data?: any - A data entry field that is preserved on a completion item
   //              between a completion and a completion resolve request.
 };
 llvm::json::Value toJSON(const CompletionItem &);
 llvm::raw_ostream &operator<<(llvm::raw_ostream &, const CompletionItem &);

clang-tools-extra/clangd/Protocol.cpp

llvm::json::Value toJSON(const CompletionItem &CI) {
   if (CI.insertTextFormat != InsertTextFormat::Missing)
     Result["insertTextFormat"] = static_cast<int>(CI.insertTextFormat);
   if (CI.textEdit)
     Result["textEdit"] = *CI.textEdit;
   if (!CI.additionalTextEdits.empty())
     Result["additionalTextEdits"] = llvm::json::Array(CI.additionalTextEdits);
   if (CI.deprecated)
     Result["deprecated"] = CI.deprecated;
+  Result["score"] = CI.score;
   return std::move(Result);
 }
 
 llvm::raw_ostream &operator<<(llvm::raw_ostream &O, const CompletionItem &I) {
   O << I.label << " - " << toJSON(I);
   return O;
 }
 

clang-tools-extra/clangd/test/completion-auto-trigger.test

 # CHECK-NEXT:    "items": [
 # CHECK-NEXT:       {
 # CHECK-NEXT:        "detail": "int",
 # CHECK-NEXT:        "filterText": "size",
 # CHECK-NEXT:        "insertText": "size",
 # CHECK-NEXT:        "insertTextFormat": 1,
 # CHECK-NEXT:        "kind": 5,
 # CHECK-NEXT:        "label": " size",
+# CHECK-NEXT:        "score": 13.200000762939453,
 # CHECK-NEXT:        "sortText": "{{.*}}size",
 # CHECK-NEXT:        "textEdit": {
 # CHECK-NEXT:          "newText": "size",
 # CHECK-NEXT:          "range": {
 # CHECK-NEXT:            "end": {
 # CHECK-NEXT:              "character": 5,
 # CHECK-NEXT:              "line": 3
 # CHECK-NEXT:            },
 # CHECK-NEXT:            "start": {
 # CHECK-NEXT:              "character": 5,
 # CHECK-NEXT:              "line": 3
 # CHECK-NEXT:            }
 # CHECK-NEXT:          }
 # CHECK-NEXT:        }
 # CHECK-NEXT:      },
 # CHECK-NEXT:      {
 # CHECK-NEXT:         "detail": "int",
 # CHECK-NEXT:         "filterText": "default_capacity",
 # CHECK-NEXT:         "insertText": "default_capacity",
 # CHECK-NEXT:         "insertTextFormat": 1,
 # CHECK-NEXT:         "kind": 10,
 # CHECK-NEXT:         "label": " default_capacity",
+# CHECK-NEXT:         "score": 2.6400001049041748,
 # CHECK-NEXT:         "sortText": "{{.*}}default_capacity",
 # CHECK-NEXT:         "textEdit": {
 # CHECK-NEXT:           "newText": "default_capacity",
 # CHECK-NEXT:           "range": {
 # CHECK-NEXT:             "end": {
 # CHECK-NEXT:               "character": 5,
 # CHECK-NEXT:               "line": 3
 # CHECK-NEXT:             },

 # CHECK-NEXT:    "items": [
 # CHECK-NEXT:      {
 # CHECK-NEXT:        "detail": "int",
 # CHECK-NEXT:        "filterText": "ns_member",
 # CHECK-NEXT:        "insertText": "ns_member",
 # CHECK-NEXT:        "insertTextFormat": 1,
 # CHECK-NEXT:        "kind": 6,
 # CHECK-NEXT:        "label": " ns_member",
+# CHECK-NEXT:        "score": 6.6000003814697266,
 # CHECK-NEXT:        "sortText": "{{.*}}ns_member",
 # CHECK-NEXT:        "textEdit": {
 # CHECK-NEXT:          "newText": "ns_member",
 # CHECK-NEXT:          "range": {
 # CHECK-NEXT:            "end": {
 # CHECK-NEXT:              "character": 6,
 # CHECK-NEXT:              "line": 6
 # CHECK-NEXT:            },

clang-tools-extra/clangd/test/completion-snippets.test

 # CHECK-NEXT:  "result": {
 # CHECK-NEXT:    "isIncomplete": {{.*}}
 # CHECK-NEXT:    "items": [
 # CHECK:           "filterText": "func_with_args",
 # CHECK-NEXT:      "insertText": "func_with_args(${1:int a}, ${2:int b})",
 # CHECK-NEXT:      "insertTextFormat": 2,
 # CHECK-NEXT:      "kind": 3,
 # CHECK-NEXT:      "label": " func_with_args(int a, int b)",
+# CHECK-NEXT:      "score": 9.9000005722045898,
 # CHECK-NEXT:      "sortText": "{{.*}}func_with_args"
 # CHECK-NEXT:      "textEdit": {
 # CHECK-NEXT:        "newText": "func_with_args(${1:int a}, ${2:int b})",
 # CHECK-NEXT:        "range": {
 # CHECK-NEXT:          "end": {
 # CHECK-NEXT:            "character": 7,
 # CHECK-NEXT:            "line": 2
 # CHECK-NEXT:          }

clang-tools-extra/clangd/test/completion.test

 # CHECK-NEXT:    "items": [
 # CHECK-NEXT:    {
 # CHECK-NEXT:      "detail": "int",
 # CHECK-NEXT:      "filterText": "a",
 # CHECK-NEXT:      "insertText": "a",
 # CHECK-NEXT:      "insertTextFormat": 1,
 # CHECK-NEXT:      "kind": 5,
 # CHECK-NEXT:      "label": " a",
+# CHECK-NEXT:      "score": 13.200000762939453,
 # CHECK-NEXT:      "sortText": "{{.*}}a"
 # CHECK-NEXT:      "textEdit": {
 # CHECK-NEXT:        "newText": "a",
 # CHECK-NEXT:        "range": {
 # CHECK-NEXT:          "end": {
 # CHECK-NEXT:            "character": 4,
 # CHECK-NEXT:            "line": 2
 # CHECK-NEXT:          }

 # CHECK-NEXT:    "items": [
 # CHECK-NEXT:    {
 # CHECK-NEXT:      "detail": "int",
 # CHECK-NEXT:      "filterText": "b",
 # CHECK-NEXT:      "insertText": "b",
 # CHECK-NEXT:      "insertTextFormat": 1,
 # CHECK-NEXT:      "kind": 5,
 # CHECK-NEXT:      "label": " b",
+# CHECK-NEXT:      "score": 13.200000762939453,
 # CHECK-NEXT:      "sortText": "{{.*}}b"
 # CHECK-NEXT:      "textEdit": {
 # CHECK-NEXT:        "newText": "b",
 # CHECK-NEXT:        "range": {
 # CHECK-NEXT:          "end": {
 # CHECK-NEXT:            "character": 4,
 # CHECK-NEXT:            "line": 2
 # CHECK-NEXT:          }

clang-tools-extra/clangd/test/protocol.test

 # CHECK-NEXT:  "result": {
 # CHECK-NEXT:    "isIncomplete": false,
 # CHECK-NEXT:    "items": [
 #      CHECK:        "filterText": "a",
 # CHECK-NEXT:        "insertText": "a",
 # CHECK-NEXT:        "insertTextFormat": 1,
 # CHECK-NEXT:        "kind": 5,
 # CHECK-NEXT:        "label": " a",
+# CHECK-NEXT:        "score": 13.200000762939453,
 # CHECK-NEXT:        "sortText": "{{.*}}"
 #      CHECK:    ]
 # CHECK-NEXT:  }
 
 X-Test: Testing
 Content-Type: application/vscode-jsonrpc; charset-utf-8
 Content-Length: 146
 Content-Type: application/vscode-jsonrpc; charset-utf-8

 # CHECK-NEXT:  "result": {
 # CHECK-NEXT:    "isIncomplete": false,
 # CHECK-NEXT:    "items": [
 #      CHECK:        "filterText": "a",
 # CHECK-NEXT:        "insertText": "a",
 # CHECK-NEXT:        "insertTextFormat": 1,
 # CHECK-NEXT:        "kind": 5,
 # CHECK-NEXT:        "label": " a",
+# CHECK-NEXT:        "score": 13.200000762939453,
 # CHECK-NEXT:        "sortText": "{{.*}}"
 #      CHECK:    ]
 # CHECK-NEXT:  }
 # STDERR: Warning: Duplicate Content-Length header received. The previous value for this message (10) was ignored.
 
 Content-Type: application/vscode-jsonrpc; charset-utf-8
 Content-Length: 10
 

 # CHECK-NEXT:  "result": {
 # CHECK-NEXT:    "isIncomplete": false,
 # CHECK-NEXT:    "items": [
 #      CHECK:        "filterText": "a",
 # CHECK-NEXT:        "insertText": "a",
 # CHECK-NEXT:        "insertTextFormat": 1,
 # CHECK-NEXT:        "kind": 5,
 # CHECK-NEXT:        "label": " a",
+# CHECK-NEXT:        "score": 13.200000762939453,
 # CHECK-NEXT:        "sortText": "{{.*}}"
 #      CHECK:    ]
 # CHECK-NEXT:  }
 Content-Length: 1024
 
 {"jsonrpc":"2.0","id":5,"method":"textDocument/completion","params":{"textDocument":{"uri":"test:/main.cpp"},"position":{"line":3,"character":5}}}
 # Test message which reads beyond the end of the stream.
 #
 # Ensure this is the last test in the file!
 # STDERR: Input was aborted. Read only {{[0-9]+}} bytes of expected {{[0-9]+}}.
 

clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

TEST(CompletionTest, Render) {
   C.RequiredQualifier = "Foo::";
   C.Scope = "ns::Foo::";
   C.Documentation = "This is x().";
   C.Includes.emplace_back();
   auto &Include = C.Includes.back();
   Include.Header = "\"foo.h\"";
   C.Kind = CompletionItemKind::Method;
   C.Score.Total = 1.0;
+  C.Score.ExcludingName = .5;
   C.Origin = SymbolOrigin::AST | SymbolOrigin::Static;
 
   CodeCompleteOptions Opts;
   Opts.IncludeIndicator.Insert = "^";
   Opts.IncludeIndicator.NoInsert = "";
   Opts.EnableSnippets = false;
 
   auto R = C.render(Opts);
   EXPECT_EQ(R.label, "Foo::x(bool) const");
   EXPECT_EQ(R.insertText, "Foo::x");
   EXPECT_EQ(R.insertTextFormat, InsertTextFormat::PlainText);
   EXPECT_EQ(R.filterText, "x");
   EXPECT_EQ(R.detail, "int\n\"foo.h\"");
   EXPECT_EQ(R.documentation, "This is x().");
   EXPECT_THAT(R.additionalTextEdits, IsEmpty());
   EXPECT_EQ(R.sortText, sortText(1.0, "x"));
   EXPECT_FALSE(R.deprecated);
+  EXPECT_EQ(R.score, .5f);
 
   Opts.EnableSnippets = true;
   R = C.render(Opts);
   EXPECT_EQ(R.insertText, "Foo::x(${0:bool})");
   EXPECT_EQ(R.insertTextFormat, InsertTextFormat::Snippet);
 
   Include.Insertion.emplace();
   R = C.render(Opts);