Expand description
§Snapshot testing toolbox
When you have to treat your tests like pets, instead of cattle
snapbox
is a snapshot-testing toolbox that is ready to use for verifying output from
- Function return values
- CLI stdout/stderr
- Filesystem changes
It is also flexible enough to build your own test harness like trycmd.
§Which tool is right
- cram: End-to-end CLI snapshotting agnostic of any programming language
- See also scrut
- trycmd: For running a lot of blunt tests (limited test predicates)
- Particular attention is given to allow the test data to be pulled into documentation, like with mdbook
snapbox
: When you want something liketrycmd
in one off cases or you need to customizetrycmd
s behavior.- assert_cmd + assert_fs: Test cases follow a certain pattern but special attention is needed in how to verify the results.
- Hand-written test cases: for peculiar circumstances
§Getting Started
Testing Functions:
assert_data_eq!
for quick and dirty snapshottingharness::Harness
for discovering test inputs and asserting against snapshot files:
Testing Commands:
cmd::Command
: Process spawning for testing of non-interactive commandscmd::OutputAssert
: Assert the state of aCommand
’sOutput
.
Testing Filesystem Interactions:
path::PathFixture
: Working directory for testsAssert
: Diff a directory against files present in a pattern directory
You can also build your own version of these with the lower-level building blocks these are made of.
Feature Flags
harness
— Simple input/output test harnessdetect-encoding
— Smarter binary file detectiondir
— Snapshotting of directoriespath
— Deprecated since 0.5.11, replaced withdir
cmd
— Snapshotting of commandsexamples
— Building of examples for snapshottingjson
— Snapshotting of jsonterm-svg
— Snapshotting of term stylingstructured-data
— Snapshotting of structured datadebug
— Extra debugging information
Default Feature Flags
diff
(enabled by default) — Fancy diffs on failurecolor
— Colored output supportcolor-auto
(enabled by default) — Auto-detect whether to use colors
§Examples
snapbox::assert_data_eq!("Hello many people!", "Hello [..] people!");
let actual = "...";
snapbox::Assert::new()
.action_env("SNAPSHOTS")
.eq_(actual, snapbox::file!["help_output_is_clean.txt"]);
snapbox::harness::Harness::new(
"tests/fixtures/invalid",
setup,
test,
)
.select(["tests/cases/*.in"])
.action_env("SNAPSHOTS")
.test();
fn setup(input_path: std::path::PathBuf) -> snapbox::harness::Case {
let name = input_path.file_name().unwrap().to_str().unwrap().to_owned();
let expected = input_path.with_extension("out");
snapbox::harness::Case {
name,
fixture: input_path,
expected,
}
}
fn test(input_path: &std::path::Path) -> Result<usize, Box<dyn std::error::Error>> {
let raw = std::fs::read_to_string(input_path)?;
let num = raw.parse::<usize>()?;
let actual = num + 10;
Ok(actual)
}
Re-exports§
pub use assert::Action;
pub use assert::Assert;
pub use data::Data;
pub use data::IntoData;
pub use data::IntoJson;
json
pub use data::ToDebug;
pub use filter::RedactedValue;
pub use filter::Redactions;
Modules§
- Run commands and assert on their behavior
- Initialize working directories and assert on how they’ve changed
- harness
harness
Harness
for discovering test inputs and asserting against snapshot files - Initialize working directories and assert on how they’ve changed
- Easier access to common traits
- Utilities to report test results to users
Macros§
- Check if a value is the same as an expected value
- Declare an expected value for an assert from a file
- Declare an expected value from within Rust source
Constants§
- DEFAULT_ACTION_ENVDeprecated
Functions§
- assert_eqDeprecatedCheck if a value is the same as an expected value
- assert_matchesDeprecatedCheck if a value matches a pattern
- Check if a path matches the content of another path, recursively
- Check if a path matches the pattern of another path, recursively
Type Aliases§
- ErrorDeprecated
- ResultDeprecated
- SubstitutionsDeprecated