Support top-level await - fixes #1 (#4)

readme.md

@@ -61,6 +61,18 @@ If we don't change the test file and we run the `tsd-check` command again, the t
 
 <img src="screenshot.png" width="1330">
 
+### Top-level `await`
+
+If your method returns a `Promise`, you can use top-level `await` to resolve the value instead of wrapping it in an `async` [IIFE](https://developer.mozilla.org/en-US/docs/Glossary/IIFE).
+
+```ts
+import {expectType} from 'tsd-check';
+import concat from '.';
+
+expectType<Promise<string>>(concat('foo', 'bar'));
+
+expectType<string>(await concat('foo', 'bar'));
+```
 
 
 ## Assertions

source/lib/compiler.ts

@@ -2,6 +2,11 @@ import * as path from 'path';
 import {createProgram, getPreEmitDiagnostics, ScriptTarget, ModuleResolutionKind, flattenDiagnosticMessageText} from 'typescript';
 import {Diagnostic, Context} from './interfaces';
 
+// List of diagnostic codes that should be ignored
+const ignoredDiagnostics = new Set<number>([
+	1308 // Support top-level `await`
+]);
+
 const loadConfig = () => {
 	return {
 		moduleResolution: ModuleResolutionKind.NodeJs,
@@ -28,7 +33,7 @@ export const getDiagnostics = (context: Context): Diagnostic[] => {
 	const result: Diagnostic[] = [];
 
 	for (const diagnostic of diagnostics) {
-		if (!diagnostic.file) {
+		if (!diagnostic.file || ignoredDiagnostics.has(diagnostic.code)) {
 			continue;
 		}