Use strict equality check by default (#68)

* test: Add failing test case.

*  fix: Use strict equality comparison by default.

Author: karol-majewski

fixtures/jest/failing-spec.ts

@@ -29,6 +29,23 @@ if (process.env.FAILING !== "0") {
         m.expect(source).toHaveSubscriptions(subs);
       })
     );
+
+    test(
+      "it should fail the strict comparison check when excess properties are present",
+      marbles(m => {
+        interface Person {
+          name: string;
+          age?: number;
+        }
+
+        const source = m.cold<Person>("a-", {
+          a: { name: "Bob", age: undefined }
+        });
+        const expected = m.cold<Person>("a-", { a: { name: "Bob" } });
+
+        m.expect(source).toBeObservable(expected);
+      })
+    );
   });
 
   describe("observe", () => {

source/jest/index.ts

@@ -40,7 +40,7 @@ export function configure(
 } {
   const { marbles } = _configure({
     ...configuration,
-    assertDeepEqual: (a, e) => expect(a).toEqual(e),
+    assertDeepEqual: (a, e) => expect(a).toStrictEqual(e),
     frameworkMatcher: true
   });
 
@@ -66,7 +66,10 @@ export function configure(
             )
           );
         } else {
-          t(c.name, marbles((m, ...rest: any[]) => func(m, c, ...rest)));
+          t(
+            c.name,
+            marbles((m, ...rest: any[]) => func(m, c, ...rest))
+          );
         }
       }, cases);
     });