| name | mcc-integration-testing |
| description | Use when proving MCC behavior on a real local Minecraft server, validating runtime or protocol changes end-to-end, exercising movement, physics, inventory, entity, chat, or terrain behavior, or running a single-version or cross-version regression sweep. |
| metadata | {"category":"discipline","triggers":["integration test","real server","local server","regression sweep","rcon","tmux","offline mode","online mode","movement","physics","inventory","entity","terrain","chat"]} |
MCC Integration Testing
Use this skill when the task is "prove it on a real server", not just "reason about whether it should work."
Read references/online-mode.md when the user asks for Microsoft login, device-code auth, or an online-mode server run. Use references/command-matrix.md for stable MCC-side and RCON-side commands.
Iron Law
Only say MCC was integration tested when MCC ran against a real local server and the claim is backed by real MCC output plus real server logs.
Calling build-only, reasoning-only, or join-only work "integration tested" is a rules violation, not shorthand.
These do not count as end-to-end proof:
- static reasoning, source comparison, or build success
- join or login success by itself
- a long-lived idle connection by itself
- a grep that only says there were no errors
- testing one shared-route version and silently claiming adjacent versions also passed
If the environment cannot run a real server, say so and report the result as unexecuted or inferred, not integration tested.
Default target
- Use
1.21.11-Vanilla unless the user asks for a different version or a version matrix.
- Use
MCC_SERVERS if it is set. Otherwise the default server root is MinecraftOfficial/downloads.
Guardrails
- Use a real local server.
- Launch MCC against an explicit
localhost:<server-port> target for repeatable local tests.
- Keep version matrices sequential in shared local environments. The tmux server harness is shared state by default.
- Prefer generated temporary MCC configs for scripted runs so one test does not contaminate the next.
- Default to offline auth in generated temp configs. Do not trust the repo-root
MinecraftClient.ini account defaults.
- If the user explicitly asks for Microsoft online login, honor that request and generate the temp config for Microsoft auth instead of offline mode.
- For Microsoft auth, prefer an interactive TTY launch with
BasicIO-NoColor so the device code is easy to read and relay to the user.
- Do not use file-input mode during Microsoft auth. Launch interactively first, complete login, then switch to scripted control only if needed.
- For online-mode tests, prefer a clean temp config with no join-time bots or scheduled tasks. Inherited
ScriptScheduler or DiscordRpc settings can pollute the session and send unintended chat right after login.
- Legacy and modern command syntax differ. Do not assume one server-command profile fits every version.
- Use actual MCC output and actual server logs for assertions. Do not invent success strings.
- Treat server
Done as startup progress, not RCON readiness. Retry the first RCON command before assuming the setup is broken.
- Run preflight before scripted test loops. On macOS, Java may be installed but not exported on PATH in the shell the harness uses.
- If a change touches shared routing or a version range, test at least one adjacent version that shares that path, or explicitly mark adjacent versions as unexecuted and inferred.
- For palette or version-content changes, probe at least one neighboring or existing item, entity, or block. Do not only check the headline addition.
- Separate product failures from harness failures. Missing logs, stale tmux state, stale
stdin.pipe, or pre-join Connection refused errors are usually environment problems until proven otherwise.
Choose the test mode
1. Single-version deep smoke
Use this when one supported version is enough and you want broad coverage:
.skills/mcc-integration-testing/scripts/run_full_spectrum_test.sh 1.21.11-Vanilla
This covers join, chat, slash commands, internal MCC commands, creative inventory, entity handling, sounds, particles, TNT, kill/respawn, and log assertions.
2. Ordered creative-mode E2E
Use this when the user asks for a regression sweep in a strict scenario order such as:
- connect
- send messages
- send commands
- receive messages
- movement
- physics
- mobs
- effects
- inventory
Broad validation should usually cover connect-test, item-test, entity-test, terrain-test, and chat-test.
Command:
MCC_SERVERS=/home/anon/Minecraft/Servers bash tools/run-creative-e2e.sh 1.21.11-Vanilla 1.21.11 modern
For legacy targets such as 1.8 or 1.8.9, switch the final argument to legacy and pass the pinned MC version.
3. Timing or cadence validation
Use this for TPS, movement-cadence, or packet-cadence work:
MinecraftClient/config/sample-script-tick-counter.cs
MinecraftClient/config/sample-script-packet-capture.cs
Run them against a real server with a temp config and summarize counts from the captured logs.
Preconditions
Before running any scenario:
- run preflight and clear stale shared state when the environment is reused
- configure the target server for offline testing
- ensure
eula=true
- ensure RCON is enabled
- build MCC unless the task explicitly reuses a fresh build
Preflight and reset helpers:
.skills/mcc-integration-testing/scripts/preflight_test_env.sh 1.21.11-Vanilla
.skills/mcc-integration-testing/scripts/reset_shared_test_state.sh 1.21.11-Vanilla
Offline configuration helper:
.skills/mcc-integration-testing/scripts/ensure_offline_server.sh 1.21.11-Vanilla
By default, the config helper prepares offline auth. To opt into another auth mode for a specific run, set:
MCC_TEST_ACCOUNT_TYPE=microsoft
MCC_TEST_PASSWORD=
Optionally override the login name with the fourth argument to the config helper.
Scripts and tools
.skills/mcc-integration-testing/scripts/ensure_offline_server.sh
- configures persistent offline mode and RCON
.skills/mcc-integration-testing/scripts/preflight_test_env.sh
- verifies Java, tmux, dotnet, python3, server directories, and resolves common Java PATH issues
.skills/mcc-integration-testing/scripts/reset_shared_test_state.sh
- clears stale tmux sessions and stale
stdin.pipe files before a rerun
.skills/mcc-integration-testing/scripts/prepare_offline_mcc_config.sh
- generates a clean temporary MCC config, prepares offline login by default, disables noisy bots, and can switch to Microsoft auth when explicitly requested
.skills/mcc-integration-testing/scripts/get_server_port.sh
- resolves the actual local server port from
server.properties or the latest server log
.skills/mcc-integration-testing/scripts/run_full_spectrum_test.sh
- single-version deep smoke with built-in assertions
.skills/mcc-integration-testing/scripts/summarize_test_run.sh
- summarize the latest full-spectrum run
tools/run-creative-e2e.sh
- ordered creative-mode E2E regression scenario
Evidence Discipline
In every report, separate:
Executed: exact scripts, commands, versions, auth mode, and whether the run was sequential or single-version
Observed: exact MCC output, exact server-log evidence, and the saved log directory
Inferred: conclusions not directly shown by that run's runtime evidence
Harness issues: setup or runner problems such as missing Java on PATH, stale tmux sessions, stale stdin.pipe, missing log artifacts, or failed config generation
Never upgrade inferred claims to observed facts. Absence of errors is supporting evidence only; pair it with a positive assertion for the feature under test.
Red Flags
Stop and fix the test plan if you are about to:
- claim movement, inventory, entity, terrain, physics, or chat coverage from join success alone
- reuse repo-root
MinecraftClient.ini or another user-local stateful config
- run multi-version tests in parallel in a shared tmux or shared server environment
- let inherited bots, schedulers, or other user-local noise send chat or commands during validation
What to report back
Always summarize:
- which version or versions were tested
- which port or ports were used
- which auth mode and scenario were used
- whether the run was sequential or single-version
- the exact scripts or commands executed
- pass or fail per major phase
- concrete evidence from MCC and server logs
- the saved log directory
- what was not executed and what remains inferred
- which adjacent versions were not run but were mentioned
When Not to Use
- build-only verification
- static protocol or source comparison with no real server run
- documentation or prompt work
- code review requests that do not ask for executed runtime proof
Troubleshooting
- If the first RCON command fails, retry it before assuming the setup is broken.
- If Java is installed but the harness still says it is missing, run
preflight_test_env.sh. This resolves common Homebrew Java paths on macOS.
- If MCC reaches Microsoft device-code login during an offline test, stop and inspect the generated temp config before retrying.
- If the user explicitly requests Microsoft online login, set
MCC_TEST_ACCOUNT_TYPE=microsoft before launching the harness.
- If the user explicitly requests Microsoft online login, use
BasicIO-NoColor in a real TTY, relay the device code from the TUI, and avoid pressing empty Enter at any auth prompt.
- If the online-mode session sends unexpected chat or commands right after join, inspect inherited bot settings first.
ChatBot.ScriptScheduler tasks and ChatBot.DiscordRpc are common sources of test noise in user-local configs.
- If
dotnet run cannot see an existing Microsoft session, check whether SessionCache.db and ProfileKeyCache.ini need to be synced from MinecraftClient/bin/Release/net10.0/ to the repo root.
- If Microsoft auth keeps prompting even with a valid session cache, verify
Account.Login matches the cached username exactly.
- If MCC reports
Connection refused, verify the launched target matches the server's actual server-port.
- If MCC reports
Connection refused immediately after a server start, also check for stale shared state: old tmux sessions, a stale stdin.pipe, or a server that never actually reached Done (.
- If multiple versions are being tested, do not start them in parallel unless the harness isolates tmux sessions and input files.
- If a test assertion fails, inspect the real MCC output before changing the code or weakening the assertion.
- If an older server behaves oddly on Linux, check
use-native-transport=false in server.properties.
- If a matrix row fails before producing
mcc.log or a command transcript, treat it as a harness failure, fix the environment, and rerun that row before drawing product conclusions.