unit tests tor tassign

Author: Seth Davenport

src/utils/shallow-equal.spec.ts

@@ -53,5 +53,10 @@ describe('Utils', () => {
         )
       ).to.equal(false);
     });
+
+    it('should return true for two references to the same thing', () => {
+      const thing = { a: 1, b: 2, c: undefined };
+      expect(shallowEqual(thing, thing)).to.equal(true);
+    });
   });
 });

src/utils/tassign.spec.ts

@@ -0,0 +1,52 @@
+import { expect } from 'chai';
+import { tassign } from './tassign';
+
+describe('tassign', () => {
+  it('Returns an object with original and new values', () => {
+    const initial = {
+      a: 1,
+      b: 2,
+    };
+
+    const assigned = {
+      b: 3,
+    };
+
+    const expected = {
+      a: 1,
+      b: 3,
+    };
+
+    expect(tassign(initial, assigned)).to.eql(expected);
+  });
+
+  it('Returns a new object reference', () => {
+    const initial = {
+      a: 1,
+      b: 2,
+    };
+
+    const assigned = {};
+
+    expect(tassign(initial, assigned)).not.to.equal(initial);
+  });
+
+  it('Does not mutate the original object', () => {
+    const initial = {
+      a: 1,
+      b: 2,
+    };
+
+    const assigned = {
+      b: 3,
+    };
+
+    const expected = {
+      a: 1,
+      b: 2,
+    };
+
+    tassign(initial, assigned);
+    expect(initial).to.eql(expected);
+  });
+});