Skip to main content

mops test

Mops can run Motoko unit tests

mops test

Put your tests in test/*.test.mo files.

All tests run as quickly as possible thanks to parallel execution.

See test package to help you write tests.

Options​

--reporter, -r​

Test reporter.

--reporter <reporter>

Available reporters:

  • verbose - print each file/suite/test name and Debug.print output
  • files - print only test files
  • compact - pretty progress bar
  • silent - print only errors

Default verbose if there is only one file to test and files otherwise.

note

Only verbose reporter prints Debug.print output.

--watch, -w​

Re-run tests every time you change *.mo files.

--watch

--mode​

Test run mode

--mode <mode>

Available modes:

  • interpreter - run tests via moc -r (default)
  • wasi - compile test file to wasm and execute it with wasmtime. Useful, when you use to_candid/from_candid, or if you get stackoverflow errors.

You can also specify wasi mode for a specific test file by adding the line below as the first line in the test file

// @testmode wasi

Replica tests

Replica tests are useful if you need to test actor code which relies on the IC API(cycles, timers, canister upgrades, etc.).

To run replica tests, your test file should look like this:

...

actor {
  public func runTests() : async () {
    // your tests here
  };
};

See example here.

Under the hood, Mops will:

  • Start a local replica on port 4945
  • Compile test files and deploy them
  • Call runTests method of the deployed canister

--replica​

Which replica to use to run actor tests.

Default pocket-ic if pocket-ic is specified in mops.toml in [toolchain] section, otherwise dfx.

Possible values:

  • dfx - use dfx local replica
  • pocket-ic - use PocketIC light replica via pic.js wrapper
info

If you run mops test --replica pocket-ic AND pocket-ic is not specified in mops.toml in [toolchain] section, Mops will use pocket-ic replica that comes with dfx (dfx start --pocketic).

--verbose​

Show replica logs