Filling Tests at a Prompt¶
The execution-spec-tests test framework uses the pytest framework for test case collection and execution. The fill command is essentially an alias for pytest, which uses several custom pytest plugins to run transition tools against test cases and generate JSON fixtures.
Options specific to execution-spec-tests
The command-line options specific to filling tests can be listed via:
fill --help
See Custom fill Command-Line Options for all options.
Collection - Test Exploration¶
The test cases implemented in the ./tests sub-directory can be listed in the console using:
fill --collect-only
and can be filtered (by test path, function and parameter substring):
fill --collect-only -k warm_coinbase
Docstrings are additionally displayed when ran verbosely:
fill --collect-only -k warm_coinbase -vv
Execution¶
By default, test cases are filled for all forks already deployed to mainnet, but not for forks still under active development, i.e., as of time of writing, Q2 2023:
fill
will generate fixtures for test cases from Frontier to Shanghai.
To generate all the test fixtures defined in the ./tests/shanghai sub-directory and write them to the ./fixtures-shanghai directory, run fill in the top-level directory as:
fill ./tests/shanghai --output="fixtures-shanghai"
Test case verification
Note, that the (limited set of) test post conditions are tested against the output of the evm t8n command during test generation.
To generate all the test fixtures in the tests/shanghai/eip3651_warm_coinbase/test_warm_coinbase.py module, for example, run:
fill tests/shanghai/eip3651_warm_coinbase/test_warm_coinbase.py
To generate specific test fixtures from a specific test function or even test function and parameter set, obtain the corresponding test ID using:
fill --collect-only -q -k test_warm_coinbase
This filters the tests by test_warm_coinbase. Then find the relevant test ID in the console output and provide it to fill, for example, for a test function:
fill tests/shanghai/eip3651_warm_coinbase/test_warm_coinbase.py::test_warm_coinbase_gas_usage
or, for a test function and specific parameter combination:
fill tests/shanghai/eip3651_warm_coinbase/test_warm_coinbase.py::test_warm_coinbase_gas_usage[fork_Paris-DELEGATECALL]
Execution for Development Forks¶
By default, test cases are not filled for upcoming Ethereum forks so that they can be readily filled using the evm tool from the latest geth release.
In order to fill test cases for an upcoming fork, ensure that the evm tool used supports that fork and features under test and use the --until or --fork flag.
For example, as of Q2 2023, the current fork under active development is Cancun:
fill --until Cancun
Debugging the t8n Command¶
The --evm-dump-dir flag can be used to dump the inputs and outputs of every call made to the t8n command for debugging purposes, see Debugging Transition Tools.
Other Useful Pytest Command-Line Options¶
fill -vv # More verbose output
fill -x # Exit instantly on first error or failed test case
fill --pdb -nauto # Drop into the debugger upon error in a test case
fill -s # Print stdout from tests to the console during execution
Custom fill Command-Line Options¶
To see all the options available to fill, including pytest and pytest plugin options, use --pytest-help.
To list the options that only specific to fill, use:
fill --help
Output:
usage: fill [-h] [--strict-alloc] [--ca-start CA_START] [--ca-incr CA_INCR]
[--evm-code-type EVM_CODE_TYPE] [--solc-bin SOLC_BIN]
[--solc-version SOLC_VERSION] [--evm-bin EVM_BIN] [--traces]
[--verify-fixtures] [--verify-fixtures-bin VERIFY_FIXTURES_BIN]
[--filler-path FILLER_PATH] [--output OUTPUT] [--flat-output]
[--single-fixture-per-file] [--no-html] [--strict-alloc]
[--ca-start CA_START] [--ca-incr CA_INCR] [--build-name BUILD_NAME]
[--evm-dump-dir EVM_DUMP_DIR] [--forks] [--fork FORK] [--from FROM]
[--until UNTIL]
options:
-h, --help show this help message and exit
Arguments defining pre-allocation behavior.:
--strict-alloc [DEBUG ONLY] Disallows deploying a contract in a
predefined address.
--ca-start CA_START, --contract-address-start CA_START
The starting address from which tests will deploy
contracts.
--ca-incr CA_INCR, --contract-address-increment CA_INCR
The address increment value to each deployed contract by
a test.
--evm-code-type EVM_CODE_TYPE
Type of EVM code to deploy in each test by default.
Arguments defining the solc executable:
--solc-bin SOLC_BIN Path to a solc executable (for Yul source compilation).
No default; if unspecified `--solc-version` is used.
--solc-version SOLC_VERSION
Version of the solc compiler to use. Default: 0.8.24.
Arguments defining evm executable behavior:
--evm-bin EVM_BIN Path to an evm executable that provides `t8n`. Default:
First 'evm' entry in PATH.
--traces Collect traces of the execution information from the
transition tool.
--verify-fixtures Verify generated fixture JSON files using geth's evm
blocktest command. By default, the same evm binary as for
the t8n tool is used. A different (geth) evm binary may
be specified via --verify-fixtures-bin, this must be
specified if filling with a non-geth t8n tool that does
not support blocktest.
--verify-fixtures-bin VERIFY_FIXTURES_BIN
Path to an evm executable that provides the `blocktest`
command. Default: The first (geth) 'evm' entry in PATH.
Arguments defining filler location and output:
--filler-path FILLER_PATH
Path to filler directives
--output OUTPUT Directory path to store the generated test fixtures. If
the specified path ends in '.tar.gz', then the specified
tarball is additionally created (the fixtures are still
written to the specified path without the '.tar.gz'
suffix). Can be deleted. Default: './fixtures'.
--flat-output Output each test case in the directory without the folder
structure.
--single-fixture-per-file
Don't group fixtures in JSON files by test function;
write each fixture to its own file. This can be used to
increase the granularity of --verify-fixtures.
--no-html Don't generate an HTML test report (in the output
directory). The --html flag can be used to specify a
different path.
--build-name BUILD_NAME
Specify a build name for the fixtures.ini file, e.g.,
'stable'.
--index Generate an index file for all produced fixtures.
Arguments defining debug behavior:
--evm-dump-dir EVM_DUMP_DIR, --t8n-dump-dir EVM_DUMP_DIR
Path to dump the transition tool debug output.
Specify the fork range to generate fixtures for:
--forks Display forks supported by the test framework and exit.
--fork FORK Only fill tests for the specified fork.
--from FROM Fill tests from and including the specified fork.
--until UNTIL Fill tests until and including the specified fork.
Exit: After displaying help.