(perf) simple performance tests (#819)

part of #676

packages/language-server/test/plugins/typescript/testfiles/performance.svelte

@@ -0,0 +1,30 @@
+<script lang="ts">
+    function aFunction(param: string) {
+        param += 1; // should error
+        const foo = subFunction();
+
+        function subFunction() {
+            return param ? 1 : 2;
+        }
+    }
+
+    function action(node: HTMLElement) {
+        aFunction(true); // should error
+        const foo = 'bar';
+    }
+</script>
+
+<div use:action>
+    <p>lorem ipsum</p>
+    <slot />
+</div>
+
+<NonExistentComponent
+    propA={1}
+    on:event={(evt) => {
+        const result = evt.detail ? aFunction(false) : aFunction('right');
+        result;
+    }}
+>
+    <p>Inner Content</p>
+</NonExistentComponent>

packages/language-server/test/plugins/typescript/typescript-performance.test.ts

@@ -0,0 +1,46 @@
+import * as path from 'path';
+import { performance } from 'perf_hooks';
+import ts from 'typescript';
+import { Position, Range } from 'vscode-languageserver';
+import { Document, DocumentManager } from '../../../src/lib/documents';
+import { LSConfigManager } from '../../../src/ls-config';
+import { TypeScriptPlugin } from '../../../src/plugins';
+import { pathToUrl } from '../../../src/utils';
+
+describe('TypeScript Plugin Performance Tests', () => {
+    function setup(filename: string) {
+        const docManager = new DocumentManager(() => document);
+        const testDir = path.join(__dirname, 'testfiles');
+        const filePath = path.join(testDir, filename);
+        const uri = pathToUrl(filePath);
+        const document = new Document(uri, ts.sys.readFile(filePath) || '');
+        const pluginManager = new LSConfigManager();
+        const plugin = new TypeScriptPlugin(docManager, pluginManager, [pathToUrl(testDir)]);
+        docManager.openDocument({ uri, text: document.getText() });
+        const updateDocument = (newText: string) =>
+            docManager.updateDocument({ uri, version: 1 }, [
+                { range: Range.create(Position.create(9, 0), Position.create(9, 0)), text: newText }
+            ]);
+        return { plugin, document, updateDocument };
+    }
+
+    it('should be fast enough', async () => {
+        const { document, plugin, updateDocument } = setup('performance');
+
+        const start = performance.now();
+        for (let i = 0; i < 1000; i++) {
+            await plugin.doHover(document, Position.create(1, 15));
+            await plugin.getDiagnostics(document);
+            await plugin.findReferences(document, Position.create(1, 15), {
+                includeDeclaration: true
+            });
+            await plugin.getDocumentSymbols(document);
+            await plugin.getSemanticTokens(document);
+            await plugin.prepareRename(document, Position.create(1, 15));
+            updateDocument('function asd() {}\n');
+        }
+        const end = performance.now();
+
+        console.log(`Performance test took ${end - start}ms`);
+    }).timeout(10000);
+});