1 files changed, 81 insertions, 0 deletions
diff --git a/browser/components/places/tests/unit/test_PUIU_title_difference_spotter.js b/browser/components/places/tests/unit/test_PUIU_title_difference_spotter.js
new file mode 100644
index 0000000000..aaa4db6bb2
--- /dev/null
+++ b/browser/components/places/tests/unit/test_PUIU_title_difference_spotter.js
@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests the difference indication for titles.
+ */
+
+const TESTS = [
+  {
+    title: null,
+    expected: undefined,
+  },
+  {
+    title: "Short title",
+    expected: undefined,
+  },
+  {
+    title: "Short title2",
+    expected: undefined,
+  },
+  {
+    title: "Long title same as another",
+    expected: undefined,
+  },
+  {
+    title: "Long title same as another",
+    expected: undefined,
+  },
+  {
+    title: "Long title with difference at the end 1",
+    expected: 38,
+  },
+  {
+    title: "Long title with difference at the end 2",
+    expected: 38,
+  },
+  {
+    title: "A long title with difference 123456 in the middle.",
+    expected: 30,
+  },
+  {
+    title: "A long title with difference 135246 in the middle.",
+    expected: 30,
+  },
+  {
+    title:
+      "Some long titles with variable 12345678 differences to 13572468 other titles",
+    expected: 32,
+  },
+  {
+    title:
+      "Some long titles with variable 12345678 differences to 15263748 other titles",
+    expected: 32,
+  },
+  {
+    title:
+      "Some long titles with variable 15263748 differences to 12345678 other titles",
+    expected: 32,
+  },
+  {
+    title: "One long title which will be shorter than the other one",
+    expected: 40,
+  },
+  {
+    title:
+      "One long title which will be shorter that the other one (not this one)",
+    expected: 40,
+  },
+];
+
+add_task(async function test_difference_finding() {
+  PlacesUIUtils.insertTitleStartDiffs(TESTS);
+
+  for (let result of TESTS) {
+    Assert.equal(
+      result.titleDifferentIndex,
+      result.expected,
+      `Should have returned the correct index for "${result.title}"`
+    );
+  }
+});