Struct snapbox::Assert

pub struct Assert { /* private fields */ }

Snapshot assertion against a file’s contents

Useful for one-off assertions with the snapshot stored in a file

Examples

let actual = "something";
Assert::new().matches(file!["output.txt"], actual);

Implementations

impl Assert

Assertions

pub fn new() -> Self

pub fn eq(&self, expected: impl Into<Data>, actual: impl Into<Data>)

Check if a value is the same as an expected value

When the content is text, newlines are normalized.

let actual = "something";
let expected = "something";
Assert::new().eq(expected, actual);

Can combine this with file!

let actual = "something";
Assert::new().eq(file!["output.txt"], actual);

pub fn matches(&self, pattern: impl Into<Data>, actual: impl Into<Data>)

Check if a value matches a pattern

Pattern syntax:

• ... is a line-wildcard when on a line by itself
• [..] is a character-wildcard when inside a line
• [EXE] matches .exe on Windows

Normalization:

• Newlines
• \ to /

let actual = "something";
let expected = "so[..]g";
Assert::new().matches(expected, actual);

Can combine this with file!

let actual = "something";
Assert::new().matches(file!["output.txt"], actual);

impl Assert

Directory Assertions

pub fn subset_eq( &self, expected_root: impl Into<PathBuf>, actual_root: impl Into<PathBuf> )

Available on crate feature path only.

pub fn subset_matches( &self, pattern_root: impl Into<PathBuf>, actual_root: impl Into<PathBuf> )

Available on crate feature path only.

impl Assert

Customize Behavior

pub fn palette(self, palette: Palette) -> Self

Override the color palette

pub fn action_env(self, var_name: &str) -> Self

Read the failure action from an environment variable

pub fn action(self, action: Action) -> Self

Override the failure action

pub fn substitutions(self, substitutions: Substitutions) -> Self

Override the default Substitutions

pub fn normalize_paths(self, yes: bool) -> Self

Specify whether text should have path separators normalized

The default is normalized

Trait Implementations

impl Clone for Assert

fn clone(&self) -> Assert

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Assert

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Assert

fn default() -> Self

Returns the “default value” for a type.