Fix that bug

types/jasmine/index.d.ts

@@ -88,7 +88,7 @@ declare function expect<T>(actual: ArrayLike<T>): jasmine.ArrayLikeMatchers<T>;
  * Create an expectation for a spec.
  * @param actual Actual computed value to test expectations against.
  */
-declare function expect<T>(actual?: T): jasmine.Matchers<T>;
+declare function expect<T>(actual: T): jasmine.Matchers<T>;
 
 /**
  * Explicitly mark a spec as failed.

types/jasmine/jasmine-tests.ts

@@ -672,7 +672,7 @@ describe("Multiple spies, when created manually", () => {
 
 describe("jasmine.nothing", () => {
     it("matches any value", () => {
-        expect().nothing();
+        expect("s").nothing();
     });
 });