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unitizeR - Interactive R Unit Tests

TL;DR

unitizer simplifies creation, review, and debugging of tests in R. It automatically stores R expressions and the values they produce, so explicit expectations are unnecessary. Every test is easy to write with unitizer because testing and using a function are the same. This encourages non-trivial tests that better represent actual usage.

Tests fail when the value associated with an expression changes. In interactive mode you are dropped directly into the failing test environment so you may debug it.

unitizer is on CRAN:

install.packages('unitizer')

It bakes in a lot of contextual help so you can get started without reading all the documentation. Try the demo to get an idea:

library(unitizer)
demo(unitizer)

Or check out the screencast to see unitizer in action.

Why Another Testing Framework?

Automated Test Formalization

Are you tired of the deparse/dput then copy-paste R objects into test file dance, or do you use testthat::expect_equal_to_reference or other snapshot testing a lot?

With unitizer you interactively review your code as you would when typing it at the R prompt. Then, with a single keystroke, you tell unitizer to store the code, and any values, warnings, or errors it produced, thereby creating a formal regression test.

Streamlined Debugging

Do you wish the nature of a test failure was more immediately obvious?

When tests fail, you are shown a proper diff so you can clearly identify how the test failed:

Do you wish that you could start debugging your failed tests without additional set-up work?

unitizer drops you in the test environment so you can debug why the test failed without further ado:

Fast Test Updates

Do you avoid improvements to your functions because that would require painstakingly updating many tests?

The diffs for the failed tests let you immediately confirm only what you intended changed. Then you can update each test with a single keystroke.

Usage

unitizer stores R expressions and the result of evaluating them so that it can detect code regressions. This is akin to saving test output to a .Rout.save file as documented in Writing R Extensions, except that we’re storing the actual R objects and it is much easier to review them.

To use unitizer:

  • Write test expressions as you would when informally testing code on the command line, and save them to a file (e.g. “my_file_name.R”).
  • Run unitize("my_file_name.R") and follow the prompts.
  • Continue developing your package.
  • Re-run unitize("my_file_name.R"); if any tests fail you will be able to review and debug them in an interactive prompt.

unitizer can run in a non-interactive mode for use with R CMD check.

Documentation

Related Packages

Acknowledgments

Thank you to:

About the Author

Brodie Gaslam is a hobbyist programmer based in the US East Coast.

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Version

Install

install.packages('unitizer')

Monthly Downloads

9,947

Version

1.4.23

License

GPL-2 | GPL-3

Issues

Pull Requests

Stars

Forks

Maintainer

Brodie Gaslam

Last Published

October 22nd, 2025

Functions in unitizer (1.4.23)

flattenUntz

Reduce S4 objects Into Lists
print.bullet

Print Methods for UL and OL objects
options_zero

Set Options to Initial Zero State
getFun

Utility Function
length,unitizerSection-method

Compute Length of a unitizerSection-class
sizeUntz

Utility To Examine Object Size
testFuns

Store Functions for New vs. Reference Test Comparisons
set_unitizer

Set and Retrieve Store Contents
show,unitizerChanges-method

Print Out A Summary Of the Changes
testthat_translate_file

Convert a testthat Test File to a unitizer
testthat_transcribe_file

Transcribes a testtaht File Into unitizer Format
show.conditionList

Prints A list of Conditions
sizeRDS

Measure object size as an RDS
unitize

Unitize an R Test Script
show,unitizerItemTestsErrorsDiff-method

Show Method for unitizerItemTestsErrorsDiff objects
text_wrap

Text Wrapping Utilities
unitizer_prompt

Interactively Retrieve User Input
unitizer_result

Return Values and Related Methods for unitize Functions
show,unitizerItemTestsErrorsDiffs-method

Show Method for unitizerItemTestsErrorsDiffs objects
unitizerState

Tests and Session State
unitizerSection-class

Contains Representation For a Section of Tests
unitizerList

S4 Object To Implement Base List Methods
unitizer

unitizer
unitizerChanges-class

Summary of Changes
valid_names

Make Valid Names
validate_pre_post

Helper function for validations
unitizer.opts

Unitizer Options
show,unitizerDummy-method

Documentation Block for Internal S4 Methods
unitizer_ls

An `ls` Like Function
unitizerTests-class

Collections of Calls For Testing
unitizer_sect

Define a unitizer Section
all_eq

Like all.equal but Returns Empty String If Not all.equal
cap_first

Captalizes or Decapitalizes First Letter
desc

One Line Description of Object
conditionList

Contains A List of Conditions
all.equal.condition

Compare Conditions
unitizer_demo

Demo Details and Helper Functions
infer_unitizer_location

Infers Possible Unitizer Path From Context
filename_to_storeid

Create a Store ID from a Test File Name
mock_item

Generates a Dummy Item For Use in Examples
repair_environments

Repair Environment Chains
as.character.bullet

Produce Character Vector Representation of Bullet Lists
capture_output

Capture Both StdOut and StdErr
as.expression,unitizerList-method

Coerce to expression by returning items coerced to expressions
run_ls

Worker function to actually execute the `ls` work
as.character,unitizerChanges-method

Print Out A Summary Of the Changes
invalidateLs

Clears ls Info and Marks as Invalid
$,unitizerItemTestsErrorsDiffs-method

Subsetting Methods for unitizerItemTestsErrorsDiffs objects
nextItem,unitizerList-method

Iterate through items of a unitizerList ObjectJK
editCalls

Edit Calls In Unitizer
$.unitizerItem

Retrieve Test Contents From Test Item
healEnvs

Fix Environment Ancestries
unitizerGlobalBase-class

Structures For Tracking Global Options
length,unitizerChanges-method

Return Sum of Total Changes