[Unittest] Add unit tests to UIString

Bug: 1009443
Change-Id: I4f82d785e5d2f6ab2b2d3a6b4e735961ff906c0e
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2046554
Reviewed-by: Paul Lewis <aerotwist@chromium.org>
Commit-Queue: Jack Franklin <jacktfranklin@chromium.org>

test/unittests/front_end/common/UIString.ts

@@ -14,4 +14,27 @@ describe('UIString', () => {
       values: [],
     }));
   });
+
+  it('serializes UI strings and includes any values', () => {
+    const output = Common.UIString.serializeUIString('a string', ['value1', 'value2']);
+    assert.equal(output, JSON.stringify({
+      messageParts: ['a string'],
+      values: ['value1', 'value2'],
+    }));
+  });
+
+  it('deserializes UI strings', () => {
+    const inputString = 'a string';
+    const serializedString = Common.UIString.serializeUIString(inputString);
+    const deserializedString = Common.UIString.deserializeUIString(serializedString);
+    assert.deepEqual(deserializedString, {
+      messageParts: [inputString],
+      values: [],
+    });
+  });
+
+  it('returns an empty object if no string is given to deserialize', () => {
+    const output = Common.UIString.deserializeUIString();
+    assert.deepEqual(output, {});
+  });
 });