Mobile Location Testing Strategies for the Tongcheng Travel App

Background – Tongcheng Travel is a global travel app used by users on various networks and devices; testing all possible location scenarios manually is infeasible, so a systematic approach to mobile location testing is required.

Content Overview – The article covers five main topics: understanding the app's location mechanism, common third‑party map SDKs and coordinate systems, designing a location test plan, case studies of location‑related issues, and a summary.

1. Understanding the App Location Mechanism

1) System‑level positioning methods include cellular, GPS, and Wi‑Fi.

2) Common third‑party SDKs such as Baidu, Gaode (Amap), and Google Maps are used.

3) The app’s location processing flow is illustrated with diagrams.

2. Third‑Party SDKs and Coordinate Systems

The global standard is WGS‑84; China’s GCJ‑02 (Mars coordinate) adds an offset, and some providers apply further transformations, leading to inconsistencies between SDKs.

3. Location Test Plan

• Overall mapping of test points and city‑level scenarios.

• Specific city‑dimension test items: successful location, failure, unsupported cities, direct‑controlled municipalities, and overseas cities.

• Test techniques include obtaining latitude/longitude via Baidu, Gaode, or Google pickers, using internal debug tools to inject custom coordinates, and restarting the app to trigger location updates.

4. Location Issue Cases

Case 1 (Taiwan) – The app returned China as the location; the cause was missing city info from Gaode. The solution was to add a Taiwan coordinate region and use Google reverse‑geocoding.

Case 2 (Coordinate bias) – Converting Gaode coordinates to WGS‑84 before calling Google caused offset errors; the fix was to use Gaode’s raw coordinates directly with Google API.

Case 3 (Overseas city accuracy) – Only country‑level data was matched; the root cause was incomplete data and ambiguous short codes. Solutions included enriching overseas city data, adjusting server matching logic to prioritize country code before short code, and extensive manual verification.

5. Summary

The article shares the design of location testing solutions for the Tongcheng Travel client, presents several real‑world issues and their resolutions, and emphasizes the need for comprehensive knowledge of location services before testing, helping developers and testers reduce online problems and improve user experience.