3 unstable releases
0.2.0 | Jun 2, 2023 |
---|---|
0.1.1 | May 2, 2023 |
0.1.0 | Apr 9, 2023 |
#616 in Testing
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29KB
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namaka
Snapshot testing for Nix based on haumea
Quick Start
nix flake init -t github:nix-community/namaka
nix develop # add namaka to the environment
namaka check # run checks
namaka review # review pending snapshots
Versioning
Namaka follows semantic versioning. Breaking changes can happen in main branch at any time, so it is recommended to pin namaka to a specific tag. A list of available versions can be found on the releases page.
Usage
Usage: namaka [OPTIONS] [DIR] <COMMAND>
Commands:
check Wrapper around `nix flake check` to prepare snapshots for failed tests [aliases: c]
clean Remove unused and pending snapshots [aliases: cl]
review Review pending snapshots and selectively accept or reject them [aliases: r]
help Print this message or the help of the given subcommand(s)
Arguments:
[DIR] Change to this working directory
Options:
-c, --cmd <CMD>... Command to run instead of `nix flake check`
-h, --help Print help (see more with '--help')
-V, --version Print version
load
Type: { ... } -> { }
Wrapper around haumea.load
to load snapshot tests from a directory.
It throws an error if any of the tests fail, otherwise it always returns { }
.
load { src = ./tests; }
will load tests from the tests
directory,
which should be structured like this:
tests
├─ foo/
│ ├─ expr.nix
└─ bar/
├─ expr.nix
└─ format.nix (optional)
expr.nix
contains the Nix expression you want to test.
format.nix
contains a Nix string specifying how the expression should be serialized.
Here are the possible values:
"json"
serializes the expression usingbuiltins.toJSON
(default)"pretty"
serializes the expression usinglib.generators.toPretty { }
"string"
serializes the string as is
See the tests directory or one of the templates for an example.
Ignore the _snapshots
directory, as it is automatically generated by namaka.
The rest of the available options are documented in haumea.load
,
as they will function exactly the same.
Configuration
namaka
will try to read namaka.toml
in the working directory.
Here is an example configuration file (all fields are optional):
# namaka.toml
# change the working directory
# this stacks with the command line option
#`namaka check bar` will read `bar/namaka.toml` and change the working directory to `bar/foo`
dir = "foo"
[check]
# the command to run with `namaka check`
# defaults to `nix flake check --extra-experimental-features "flakes nix-command"`
cmd = ["nix", "eval", "./dev#checks"]
[eval]
# the command to run with `namaka review` and `namaka clean`
# defaults to `nix eval ./checks --extra-experimental-features "flakes nix-command"`
cmd = ["nix", "flake", "check"]
Snapshot Testing
Snapshot testing is a strategy that allows you to write tests without manually writing reference values.
Instead of assert foo == bar;
, you only need to have foo
,
and namaka will store bar
in a snapshot file and ask you to update it with namaka review
.
To start, you can follow the Quick Start guide, or refer to load for more detailed documentation.
Related Tools
Dependencies
~22–35MB
~543K SLoC