Overview

This reference is generated from the source docstrings and is grouped by the mixin that implements each assertion, mirroring the code layout.

The assertions available on a value are the union of the mixins for its type. On a string (assert_that("x")) that is everything on:

• String assertions
• Containment assertions
• Collection assertions
• File & path assertions
• Core & objects, apart from matches_structure(), which a type checker offers on mappings, models and objects only.

For a task-oriented view organized by value type instead, see the Type assertions guide.

• Entry points - the top-level functions such as assert_that, assert_conforms, assert_warn, soft_assertions, and fail.
• Matchers - the match.* namespace of composable matchers.
• Core & objects - assertions available on every value (equality, identity, satisfies, ...).
• Type-specific pages - strings, numbers, collections, dicts, dates, files, bytes.
• Dynamic assertions - the has_<name>() family.
• Exception & callable assertions - raises(), caused_by(), contains_error(), errors(), raised().
• Extracting, JSON assertions, Data frame & array assertions, and Snapshot assertions.
• Structured failures, Warning assertions, and Async & eventual assertions.

Signatures here are the runtime implementations. How the static return type narrows per value type (the typed overloads that drive editor autocomplete) is explained in Type safety.