Fix symbol providers to return real instances

Fixes #920.

See microsoft/vscode#50207.

src/providers/dart_symbol_provider.ts

@@ -1,5 +1,5 @@
 import * as path from "path";
-import { CancellationToken, DocumentSymbolProvider, SymbolInformation, TextDocument, Uri, WorkspaceSymbolProvider, workspace } from "vscode";
+import { CancellationToken, DocumentSymbolProvider, Location, SymbolInformation, TextDocument, Uri, workspace, WorkspaceSymbolProvider } from "vscode";
 import * as as from "../analysis/analysis_server_types";
 import { Analyzer, getSymbolKindForElementKind } from "../analysis/analyzer";
 import { fsPath, toRangeOnLine } from "../utils";
@@ -55,15 +55,15 @@ export class DartSymbolProvider implements WorkspaceSymbolProvider, DocumentSymb
 			containerName = result.className || "";
 		}
 
-		return {
-			containerName,
-			kind: getSymbolKindForElementKind(result.kind),
-			location: {
-				range: toRangeOnLine({ startLine: result.line, startColumn: result.column, length: 0 }),
-				uri: Uri.file(file),
-			},
+		return new SymbolInformation(
 			name,
-		};
+			getSymbolKindForElementKind(result.kind),
+			containerName,
+			new Location(
+				Uri.file(file),
+				toRangeOnLine({ startLine: result.line, startColumn: result.column, length: 0 }),
+			),
+		);
 	}
 
 	private createDisplayPath(inputPath: string): string {

src/providers/legacy_dart_document_symbol_provider.ts

@@ -1,4 +1,4 @@
-import { CancellationToken, DocumentSymbolProvider, Range, SymbolInformation, TextDocument, Uri } from "vscode";
+import { CancellationToken, DocumentSymbolProvider, Location, Range, SymbolInformation, TextDocument, Uri } from "vscode";
 import * as as from "../analysis/analysis_server_types";
 import { Analyzer, getSymbolKindForElementKind } from "../analysis/analyzer";
 import { fsPath } from "../utils";
@@ -42,15 +42,15 @@ export class LegacyDartDocumentSymbolProvider implements DocumentSymbolProvider
 		if (element.parameters && element.kind !== "SETTER")
 			name = `${name}${element.parameters}`;
 
-		symbols.push({
-			containerName: parent && parent.name,
-			kind: getSymbolKindForElementKind(element.kind),
-			location: {
-				range: this.getRange(document, outline),
-				uri: Uri.file(element.location.file),
-			},
+		symbols.push(new SymbolInformation(
 			name,
-		});
+			getSymbolKindForElementKind(element.kind),
+			parent && parent.name,
+			new Location(
+				Uri.file(element.location.file),
+				this.getRange(document, outline),
+			),
+		));
 
 		if (outline.children) {
 			for (const child of outline.children)