[test][tools] Add test for timline.mjs

Bug: v8:10668
Change-Id: I51f81a66408a4b262f9ac7e6421609c5e485f779
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2435107
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70174}

test/mjsunit/BUILD.gn

@@ -12,6 +12,7 @@ group("v8_mjsunit") {
 
   data = [
     "./",
+    "../../tools/arguments.js",
     "../../tools/clusterfuzz/v8_mock.js",
     "../../tools/clusterfuzz/v8_mock_archs.js",
     "../../tools/clusterfuzz/v8_mock_webassembly.js",
@@ -24,6 +25,8 @@ group("v8_mjsunit") {
     "../../tools/profile_view.mjs",
     "../../tools/splaytree.mjs",
     "../../tools/tickprocessor.mjs",
+    "../../tools/system-analyzer/log/log.mjs",
+    "../../tools/system-analyzer/timeline.mjs",
     "../../tools/dumpcpp.mjs",
   ]
 }

test/mjsunit/tools/timeline.mjs

@@ -0,0 +1,31 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import { Timeline } from "../../../tools/system-analyzer/timeline.mjs";
+import { Event } from "../../../tools/system-analyzer/log/log.mjs";
+
+
+(function testTimeline() {
+  let timeline = new Timeline();
+  let id1 = "0x3e7e082470cd";
+  let id2 = "0x3e7e082470ad";
+  let time = 12;
+  let event1 = new Event(id1, time);
+  let event2 = new Event(id1, time + 1);
+  let event3 = new Event(id1, time + 2);
+  let event4 = new Event(id1, time + 3);
+  let event5 = new Event(id2, time + 3);
+  timeline.push(event1);
+  timeline.push(event2);
+  timeline.push(event3);
+  timeline.push(event4);
+  timeline.push(event5);
+  let startTime = time;
+  let endTime = time + 2;
+  timeline.selectTimeRange(startTime, endTime);
+  assertArrayEquals(timeline.selection, [event1, event2, event3]);
+  let entryIdx = timeline.find(time + 1);
+  let entry = timeline.at(entryIdx);
+  assertEquals(entry.time, time + 1);
+})();

tools/system-analyzer/timeline.mjs

@@ -76,11 +76,11 @@ class Timeline {
   }
 
   first() {
-    return this.#values.first();
+    return this.#values[0];
   }
 
   last() {
-    return this.#values.last();
+    return this.#values[this.#values.length - 1];
   }
 
   duration() {