test(lsp): add test for references in lspcmd

cmd/templ/lspcmd/lsp_test.go

@@ -319,6 +319,115 @@ func TestHover(t *testing.T) {
 	}
 }
 
+func TestReferences(t *testing.T) {
+	if testing.Short() {
+		return
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	log, _ := zap.NewProduction()
+
+	ctx, appDir, _, server, teardown, err := Setup(ctx, log)
+	if err != nil {
+		t.Fatalf("failed to setup test: %v", err)
+		return
+	}
+	defer teardown(t)
+	defer cancel()
+
+	templFile, err := os.ReadFile(appDir + "/templates.templ")
+	if err != nil {
+		t.Fatalf("failed to read file %q: %v", appDir+"/templates.templ", err)
+		return
+
+	}
+	err = server.DidOpen(ctx, &protocol.DidOpenTextDocumentParams{
+		TextDocument: protocol.TextDocumentItem{
+			URI:        uri.URI("file://" + appDir + "/templates.templ"),
+			LanguageID: "templ",
+			Version:    1,
+			Text:       string(templFile),
+		},
+	})
+	if err != nil {
+		t.Errorf("failed to register open file: %v", err)
+		return
+	}
+	log.Info("Calling References")
+
+	tests := []struct {
+		line      int
+		character int
+		assert    func(t *testing.T, l []protocol.Location) (msg string, ok bool)
+	}{
+		{
+			// this is the definition of the templ function in the templates.templ file.
+			line:      5,
+			character: 9,
+			assert: func(t *testing.T, actual []protocol.Location) (msg string, ok bool) {
+				expectedReference := []protocol.Location{
+					{
+						// This is the useage of the templ function in the main.go file.
+						URI: uri.URI("file://" + appDir + "/main.go"),
+						Range: protocol.Range{
+							Start: protocol.Position{
+								Line:      uint32(24),
+								Character: uint32(7),
+							},
+							End: protocol.Position{
+								Line:      uint32(24),
+								Character: uint32(11),
+							},
+						},
+					},
+				}
+				if diff := lspdiff.References(expectedReference, actual); diff != "" {
+					return fmt.Sprintf("Expected: %+v\nActual: %+v", expectedReference, actual), false
+				}
+				return "", true
+			},
+		},
+	}
+
+	for i, test := range tests {
+		t.Run(fmt.Sprintf("test-%d", i), func(t *testing.T) {
+			// Give CI/CD pipeline executors some time because they're often quite slow.
+			var ok bool
+			var msg string
+			for i := 0; i < 3; i++ {
+				if err != nil {
+					t.Error(err)
+					return
+				}
+				actual, err := server.References(ctx, &protocol.ReferenceParams{
+					TextDocumentPositionParams: protocol.TextDocumentPositionParams{
+						TextDocument: protocol.TextDocumentIdentifier{
+							URI: uri.URI("file://" + appDir + "/templates.templ"),
+						},
+						// Positions are zero indexed.
+						Position: protocol.Position{
+							Line:      uint32(test.line - 1),
+							Character: uint32(test.character - 1),
+						},
+					},
+				})
+				if err != nil {
+					t.Errorf("failed to get references: %v", err)
+					return
+				}
+				msg, ok = test.assert(t, actual)
+				if !ok {
+					break
+				}
+				time.Sleep(time.Millisecond * 500)
+			}
+			if !ok {
+				t.Error(msg)
+			}
+		})
+	}
+}
+
 func TestCodeAction(t *testing.T) {
 	if testing.Short() {
 		return

cmd/templ/lspcmd/lspdiff/lspdiff.go

@@ -25,6 +25,10 @@ func CompletionList(expected, actual *protocol.CompletionList) string {
 	)
 }
 
+func References(expected, actual []protocol.Location) string {
+	return cmp.Diff(expected, actual)
+}
+
 func CompletionListContainsText(cl *protocol.CompletionList, text string) bool {
 	if cl == nil {
 		return false