Walk the Dog

Ок, найду информацию про подход “выгулять собачку” в контексте сложных проектов вроде MMORPG — откуда пошло, как называется в индустрии, кто использует, и какие есть аналоги вроде smoke/sanity тестов, integration scaffolding и пр. Также поищу упоминания в dev-блогах, GDC-докладах и т.п. Дам подборку терминов, описаний и реальных кейсов.

Informal “Walk the Dog” Testing in Game Development

What is the “Walk the Dog” Test?

In game development – especially for complex systems like MMORPGs – “walk the dog” is an informal nickname for a basic end-to-end test of a game build. The idea is to bring up the minimum viable game environment (e.g. a test server and client in an MMO), then spawn a simple autonomous entity (often metaphorically a dog or similar NPC) and let it walk a predefined route and perform simple actions. This minimal scenario exercises core systems (loading a world, pathfinding, AI scripts, networking, etc.) to ensure everything “hangs together” without immediate failure (tdd - Is test-driven development a normal approach in game development? - Stack Overflow). In other words, it’s a quick smoke test of the game – does the game run and can an NPC navigate and act, indicating the major subsystems are working?

Such a test is typically automated and very simplistic. For example, a smoke test in a shooter might load a level, spawn an AI bot, have it move and shoot, then verify it behaved as expected (tdd - Is test-driven development a normal approach in game development? - Stack Overflow). If the bot can walk its doggy path successfully, the build is at least fundamentally sound. If even this simple loop fails (e.g. the NPC gets stuck or the server crashes), developers know something is seriously wrong with the latest build.

Is “Dog-Walking Test” an Official Term?

The term “dog-walking test” (or “выгулять собачку” in Russian) is slang rather than an official industry term. It does evoke the practice described, but you won’t find it in formal QA documentation. In industry settings, this kind of quick basic check is usually referred to as a smoke test or sanity test, or more generally a build verification test (BVT). The concept is widely used, even if the “dog” nickname isn’t universal. One developer describes essentially this process as a smoke test: “load up a level and provide a script that loads an AI agent and gives it commands. Then determine if the agent performs those commands” (tdd - Is test-driven development a normal approach in game development? - Stack Overflow) – which is exactly what “walking the dog” entails.

Importantly, this shouldn’t be confused with “dogfooding.” Dogfooding means developers/testers actively use the game as a player would (e.g. devs play nightly builds of their MMO for a while to experience it firsthand). That is a broader internal testing practice and not the same as the automated “dog-walk” smoke test. The “walk the dog” test is much more minimal and automated – it’s just to verify the game’s basic loop runs without blowing up, whereas dogfooding is about trying the actual gameplay to catch issues and assess fun.

Examples of “Walk the Dog”–Style Tests in the Industry

Although the slang varies, many studios have described automated minimal tests very similar to the “walk the dog” concept:

• Ubisoft (Massive) – The Division: In developing Tom Clancy’s The Division (an online open-world shooter), the team built automated bots to act as players for testing. One type, called a server bot, essentially roams the game world performing basic actions (moving, fighting) on autopilot. “They just teleport around the world, find NPCs to kill, shoot the NPCs and then they teleport off… They’ve got god mode so they can’t be killed and they just do this continuously… occasionally disconnect and reconnect or group up into co-op sessions” (The Secret AI Testers inside Tom Clancy’s The Division). This simple AI isn’t trying to be smart or simulate real tactics – it’s a bare-bones exercise of core systems (movement, combat, server load, group formation). The Division’s lead engineer noted that these dumb bots were critical: “we honestly would not have been able to ship a stable Division 1 or 2” without them (The Secret AI Testers inside Tom Clancy’s The Division). They served as a persistent smoke test, catching crashes or server issues in the basic game loop and providing performance metrics, long before any human testers ever could.

• CCP Games – EVE Online: CCP has written about similar approaches for EVE Online, their long-running MMO. They developed an automated testing system where a thin client (a stripped-down game client with no graphics) logs into the game and runs through a script of actions (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online). These automated EVE clients (sometimes called “agents”) fly around in the game universe performing simple tasks continuously to monitor performance and stability (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online). For instance, CCP’s QA team set up NPC characters (in invulnerable developer ships) that “will be flying ’round EVE recording the performance of EVE” as they traverse the world (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online). This is essentially a perpetual “walk the dog” test in production – the bots undock, warp through star systems, perhaps perform a few actions, ensuring that at a basic level the universe is behaving. CCP even noted that because these automated runs can be repeated exactly the same way, they’re great for comparing server performance between builds (though they acknowledged automated bots can’t fully mimic unpredictable player behavior) (Mass Testing - EVE Community).

• Rare – Sea of Thieves: Rare’s multiplayer pirate game Sea of Thieves uses Unreal Engine, and the team leveraged Unreal’s built-in automation framework to test gameplay features. In a GDC talk, Rare engineers discussed how they integrated automated gameplay tests (using Unreal’s functional test system) to verify things like quests and AI in Sea of Thieves (Reto_KriegDK (u/Reto_KriegDK) - Reddit). While details are sparse publicly, it’s likely these tests involved spawning a game server, having AI ships or characters perform routine activities (sail to an island, pick up treasure, etc.), akin to a “dog-walk” of the game’s core pirate loop.

• Infinity Ward/Treyarch – Call of Duty: Even in FPS games, the idea of automated sanity tests exists. Activision engineers have spoken at GDC about automated testing and profiling for Call of Duty (Reto_KriegDK (u/Reto_KriegDK) - Reddit). For example, a test might load a level, spawn a soldier bot, have it run forward and fire a weapon. If the game crashes or the bot gets stuck, the smoke test fails. This ensures a baseline confidence that a new build isn’t utterly broken before it goes out to QA or players.

Other studios like Sony Santa Monica (God of War series) and Media Molecule (LittleBigPlanet/Dreams) have likewise built automated “smoke test” suites to catch major issues. Santa Monica’s internal tool “TestMonkey” runs simple scripted gameplay sequences after each build – e.g. launching the game, starting a level, and printing a console log if anything goes wrong ([PDF] TestMonkey: Automated Testing at Santa Monica Studio - GDC Vault). All of these are variations of the same theme: small scripted scenarios that rapidly test if the game’s basic functionalities are intact.

Related Testing Approaches and Terms

The “walk the dog” test aligns with several established testing concepts in software and game development:

• Smoke Testing: This term comes from electronics (plug it in – if you see smoke, that’s bad!). In software, a smoke test is a quick broad verification of major features on a new build (tdd - Is test-driven development a normal approach in game development? - Stack Overflow). In game dev, a smoke test might be “launch the game, load a map, spawn a character, perform a simple action, then exit.” It’s shallow and broad – meant to catch catastrophes (game fails to run or fundamental features are broken). The “dog walking” example is essentially a smoke test for an MMO world. As one engineer explains, smoke testing runs the game as a whole (not unit tests of individual components) to ensure the whole system hangs together (tdd - Is test-driven development a normal approach in game development? - Stack Overflow). If the smoke test passes, the build is stable enough for deeper testing. If it fails, QA likely cannot even start regular testing.

• Sanity Testing: Often used interchangeably with smoke testing, a sanity test generally means a quick check of specific functionality after a change to ensure it “makes sense” (i.e. nothing obviously wrong). It’s like asking “am I crazy, or does this basic thing still work?” (testing - What is a sanity test/check - Stack Overflow). In practice, game teams might do a sanity test after a minor fix – e.g. “just sanity-check that the boss AI still spawns and can be killed”. If smoke testing is a broad sweep over many core features, sanity testing is a narrow check on one area, usually done before investing time in thorough QA.

• Test Scaffolding: In game development, scaffolding refers to writing ad-hoc support code or using special modes to facilitate testing. Games are complex and not easily unit-tested in isolation, so developers create scaffolding – for example, a debug command to spawn that NPC dog and have it walk the route repeatedly. This extra code isn’t part of the shipping game; it’s a temporary framework to test or develop a feature. Scaffolding can also mean stubbing out subsystems or using simplified assets so that you can test one piece without the whole game running. The “walk the dog” setup itself is enabled by scaffolding: a special test map, a script for the NPC’s path, perhaps a cheat to make the NPC invulnerable, etc., all to test the game loop without full gameplay running. Proper scaffolding makes automated tests easier to write. (That said, game devs caution against writing too much elaborate scaffolding that doesn’t get used – it should be just enough to support your tests without becoming a maintenance burden (Is test-driven development a normal approach in game development?).)

• Minimum Viable Game Loop: This term borrows from “minimum viable product.” It means implementing the simplest playable slice of the game – the core loop – and nothing more. In a new game project, you might code the minimum loop (e.g. in a platformer: spawn character → run and jump → reach goal → repeat) to prove that the concept works. In testing terms, the minimum viable game loop can serve as a basic acceptance test for the game: if the minimal loop fails, the game is not in a viable state. When an MMO team brings up a server with one NPC and one player and that NPC can walk from point A to B, that is the minimum game loop functioning. This concept is related to smoke testing – you are testing the minimum playable functionality. Some studios explicitly aim to get a “minimum playable” early in development, which doubles as a continuous test: as long as that minimal game scenario works, the build isn’t completely broken. It’s also analogous to a “vertical slice” (a thin slice of gameplay systems), but a vertical slice often includes polish and is used for demonstrating the game, whereas a minimum viable loop is bare-bones and used internally to validate core gameplay and systems.

• Regression Testing: Once a “walk the dog” test is in place, it can be run continuously to catch regressions. A regression is when something that worked before has broken due to new changes. Automated smoke tests and bots “walking” around the world each day help ensure that yesterday’s working features haven’t collapsed today. If the NPC dog suddenly falls through the floor on today’s build, that regression gets flagged immediately, pinpointing a recent change as the likely culprit. Many game studios maintain whole suites of regression tests – from unit tests on low-level code to high-level smoke tests – especially as games receive updates and patches over years.

• Other Terms: There are many related testing methods. Soak Testing (or stability testing) is running the game for an extended time to see if it crashes or degrades (e.g. leaving that NPC dog walking in circles overnight to check for memory leaks or server slowdowns). Monkey Testing refers to random, unguided input or automation – for games, “monkey” bots might randomly press keys or move in random directions to try to crash the game in unexpected ways. And in online games, canary testing is used in deployment – not exactly a test of the build’s basics, but releasing a new build to a small subset of servers/players to ensure it’s stable before wider rollout (similar mindset of small test first). All these approaches complement each other in a modern game QA strategy.

Integration with CI/CD and Automated QA

(image) Figure: As games grow more complex, studios rely on automation (telemetry, test tools, and scripts) to reduce the burden on manual testers. Smoke tests and “dog-walk” scenarios are often integrated into continuous build systems to catch problems early.

In modern game development, Continuous Integration/Continuous Deployment (CI/CD) pipelines are increasingly used to maintain quality. This means every time developers submit new code or content, an automated build is created and a battery of tests run automatically. The “walk the dog” style test is perfect to include in a CI pipeline – it’s fast and gives immediate feedback. Studios often configure a nightly build or even per-commit build that will automatically launch the game in a test mode and run a smoke test sequence. For example, one team notes that smoke tests are run in conjunction with continuous integration to provide feedback on game behavior (tdd - Is test-driven development a normal approach in game development? - Stack Overflow). If the test fails, the CI system can alert the team that the build is busted.

In practice, a CI server might spin up a headless game server and a game client, simulate a login, spawn the test NPC, and have it walk its path. Meanwhile, it logs any errors or asserts (or uses telemetry to verify the NPC reached its destination). If anything goes wrong – say the NPC can’t complete the route – the CI marks the build as failed. This prevents bad code from progressing down the pipeline. It also frees human QA from having to repeatedly do the most basic checks; they get to focus on deeper issues once the build passes the automated smoke test.

Studios like CCP have spoken about using a dedicated farm of machines for automated tests on each new build of EVE Online, covering different hardware profiles (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online) (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online). Similarly, developers of Heroes & Generals noted they track performance and run compliance tests on nightly builds automatically (Reto_KriegDK (u/Reto_KriegDK) - Reddit). Integrating these tests with CI means that every day, first thing in the morning, the team can see if the latest build survived a suite of automated “dog walks” overnight (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online). This tight feedback loop is essential in live service games where frequent updates can introduce breaking bugs.

Finally, these automated tests play a role in continuous delivery for games (especially online titles). Before a patch is pushed to players or even to a test server, the build must pass all automated checks – including the trivial but crucial ones like our NPC walking test. In the context of CI/CD, the “walk the dog” test is a form of gate: the build cannot be deployed unless the dog successfully took its walk. It’s a simple safeguard that dramatically reduces the chance of deploying a completely unplayable build. Given that modern games can’t afford long downtimes or game-breaking bugs in production, this kind of automated sanity check has become a standard QA automation practice in the industry.

Conclusion

While the terminology “walk the dog test” might be used informally among developers (and makes for a vivid metaphor), the practice it refers to is very real and widely adopted. Whether called a smoke test, sanity test, or an automated gameplay test, the idea is to spawn something simple in the game and see if the lights stay on. From MMORPG servers spinning up a lone NPC wandering about, to shooter games running a bot through a level, these tests give developers confidence that a complex game’s foundation is intact. Alongside related methods like scaffolding of test scenarios and continuous smoke testing in CI pipelines, “walking the dog” helps game studios ensure that increasingly complex games don’t require exponentially more manual testing to maintain quality. It’s a small test with big benefits – much like a quick dog walk can reveal if something’s wrong (a loose leash or a broken sidewalk), a quick automated walk in a game world can reveal critical issues early, keeping the development process on track.

Sources:

1. Chris Howe, Stack Overflow answer: on using smoke tests (scripted AI agents running in-game) for game development (tdd - Is test-driven development a normal approach in game development? - Stack Overflow).
2. Nick Patrick, “The Secret AI Testers inside The Division”: on Ubisoft’s use of server bots that roam and test The Division’s online world (The Secret AI Testers inside Tom Clancy’s The Division) (The Secret AI Testers inside Tom Clancy’s The Division).
3. CCP Lingorm, EVE Online devblog: on automated test clients and in-game agent bots used to test EVE Online’s performance and stability (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online) (Testing, Automation, Monitoring and Benchmarking OH MY! | EVE Online).
4. CCP Habakuk, Mass Testing notes: on the use of thin clients (headless test clients) in EVE Online for repeated automated tests (Mass Testing - EVE Community).
5. Reddit AMA by Reto_KriegDK (dev on Heroes & Generals): mentions GDC talks on Unreal automation (Sea of Thieves) (Reto_KriegDK (u/Reto_KriegDK) - Reddit) and automated testing in Call of Duty (Reto_KriegDK (u/Reto_KriegDK) - Reddit).
6. Sion Sheevok, Stack Overflow: definition of sanity testing as a quick validation of obvious logic (testing - What is a sanity test/check - Stack Overflow).
7. GDC Canada 2009 – M. Vasquez: Automated QA slides stressing the need for automation (smoke tests, telemetry) as games grow in complexity (GDC 2005) (GDC 2005).

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