Struct Redactions 

pub struct Redactions { /* private fields */ }

An ordered set of text rewrites applied to a value before it is compared against (or written to) a snapshot.

Build one with the chained methods, then hand it to check!(value).matches_snapshot_with(name, &redactions) (or the inline variant). Rules run in the order they were added, each on the output of the last.

use test_better_core::TestResult;
use test_better_matchers::{eq, check};
use test_better_snapshot::Redactions;

let redactions = Redactions::new().redact_uuids();
let rendered = "user 550e8400-e29b-41d4-a716-446655440000 logged in";
check!(redactions.apply(rendered))
    .satisfies(eq("user [uuid] logged in".to_string()))?;

Implementations

impl Redactions

pub fn new() -> Redactions

An empty set: apply returns its input unchanged until a rule is added.

pub fn replace( self, needle: impl Into<String>, placeholder: impl Into<String>, ) -> Redactions

Replaces every occurrence of the literal needle with placeholder.

This is the rule for a value you already know, e.g. a generated id you captured earlier in the test. An empty needle is a no-op rule rather than a rule that matches everywhere.

pub fn redact_uuids(self) -> Redactions

Replaces every UUID (the canonical 8-4-4-4-12 hex form, either case) with [uuid].

pub fn redact_rfc3339_timestamps(self) -> Redactions

Replaces every RFC 3339 / ISO 8601 date-time (e.g. 2026-05-14T12:34:56Z, with optional fractional seconds and either a Z or a ±hh:mm offset) with [timestamp].

pub fn redact_with( self, rule: impl Fn(&str) -> String + Send + Sync + 'static, ) -> Redactions

Adds an arbitrary rewriting rule: the escape hatch for content the built-ins do not cover.

The closure is handed the running text and returns its rewritten form.

pub fn apply(&self, input: &str) -> String

Runs every rule, in order, and returns the rewritten text. With no rules added this returns input unchanged.

pub fn is_empty(&self) -> bool

Whether any rule has been added. An empty set is worth skipping: its apply is an allocation that changes nothing.

Trait Implementations

impl Debug for Redactions

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

Formats the value using the given formatter.

impl Default for Redactions

fn default() -> Redactions

Returns the “default value” for a type.