Fix startTime and endTime computation when chunks are not sorted (#111)

* Fix startTime and endTime computation when chunks are not sorted

* Bump version

package.json

@@ -1,6 +1,6 @@
 {
   "name": "rosbag",
-  "version": "3.0.0",
+  "version": "3.0.1",
   "license": "Apache-2.0",
   "repository": "cruise-automation/rosbag.js",
   "dependencies": {

src/bag.js

@@ -68,8 +68,14 @@ export default class Bag {
     this.chunkInfos = result.chunkInfos;
 
     if (chunkCount > 0) {
-      this.startTime = this.chunkInfos[0].startTime;
-      this.endTime = this.chunkInfos[chunkCount - 1].endTime;
+      // Get the earliest startTime among all chunks
+      this.startTime = this.chunkInfos
+        .map((x) => x.startTime)
+        .reduce((prev, current) => (TimeUtil.compare(prev, current) <= 0 ? prev : current));
+      // Get the latest endTime among all chunks
+      this.endTime = this.chunkInfos
+        .map((x) => x.endTime)
+        .reduce((prev, current) => (TimeUtil.compare(prev, current) > 0 ? prev : current));
     }
   }
 

src/bag.test.js

@@ -211,6 +211,14 @@ describe("rosbag - high-level api", () => {
     expect(messages).toHaveLength(9);
   });
 
+  it("computes start and end time for unsorted chunks", async () => {
+    const filename = getFixture("example-unsorted-chunks");
+    expect(fs.existsSync(filename)).toBe(true);
+    const bag = await Bag.open(filename);
+    expect(bag.startTime).toEqual({ sec: 1, nsec: 0 });
+    expect(bag.endTime).toEqual({ sec: 3, nsec: 0 });
+  });
+
   describe("compression", () => {
     it("throws if compression scheme is not registered", async () => {
       let errorThrown = false;