R: Does an object inherit from a given class?

expect_is {testthat} | R Documentation

## Does an object inherit from a given class?

### Description

`expect_is()` is an older form that uses `inherits()` without checking whether `x` is S3, S4, or neither. Instead, I'd recommend using `expect_type()`, `expect_s3_class()` or `expect_s4_class()` to more clearly convey your intent.

### Usage

    expect_is(object, class, info = NULL, label = NULL)

### Arguments

`object` | Object to test. Supports limited unquoting to make it easier to generate readable failures within a function or for loop. See quasi_label for more details.
`class` | character vector of class names

### 3rd edition

`expect_is()` is formally deprecated in the 3rd edition.

[Package testthat version 3.0.0 Index]