resultcheck

Result Stability Checks for Empirical R Projects

Overview

resultcheck provides lightweight helpers for checking whether empirical results remain unchanged across code revisions, platform differences, and package updates. Call snapshot() on key outputs (models, tables, derived datasets) in your analysis scripts to detect unintended result drift automatically during CI or local testing.

Installation

Latest Stable Version

install.packages("resultcheck")

Latest Development Version (Unstable)

# install.packages("devtools")
devtools::install_github("kv9898/resultcheck")

Workflow

The package supports a two-phase workflow:

1. Interactive development — run your analysis script and call snapshot() on objects you care about. On first run the snapshot is saved as a human-readable .md file. On subsequent interactive runs, differences are shown and you are prompted to update.

2. Automated testing — wrap your script in setup_sandbox() / run_in_sandbox() / cleanup_sandbox(). Inside run_in_sandbox(), snapshot() switches to testing mode: it errors immediately if a snapshot is missing or has changed, making the test fail.

Integrated Example

with_example() can generate this layout for documentation/testing under tempdir():

myproject/
├── _resultcheck.yml
├── analysis.R
└── tests/
    ├── _resultcheck_snaps/
    │   └── analysis/
    │       ├── model.md
    │       └── model_mismatch.md
    └── testthat/
        └── test-analysis.R

analysis.R — snapshot key results

model <- lm(mpg ~ wt, data = mtcars)
resultcheck::snapshot(model, "model")

tests/testthat/test-analysis.R — automated test

library(testthat)
library(resultcheck)

test_that("analysis produces stable results", {
  sandbox <- setup_sandbox()
  on.exit(cleanup_sandbox(sandbox), add = TRUE)

  expect_true(run_in_sandbox("analysis.R", sandbox))
})

To try this quickly without creating files in your current project:

resultcheck::with_example({
  sandbox <- setup_sandbox()
  on.exit(cleanup_sandbox(sandbox), add = TRUE)
  stopifnot(isTRUE(run_in_sandbox("analysis.R", sandbox)))
})

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Function Reference

snapshot(value, name, script_name = NULL, method = c("both", "print", "str"))

Creates or verifies a snapshot of any R object.

• First interactive run: saves the object as a human-readable .md file under tests/_resultcheck_snaps/<script>/ at the project root by default.
• Subsequent interactive runs: shows a diff and prompts to update.
• Inside run_in_sandbox(): errors if the snapshot is missing or doesn't match.
• When writing snapshots interactively: warns and shows the exact output path.

You can override the default snapshot directory in _resultcheck.yml:

snapshot:
  dir: "custom/snapshots/path"

The method argument controls how the object is serialized:

Value	Behavior
"both" (default)	Type-specific logic using both print() and str()
"print"	Only print() output is captured
"str"	Only str() output is captured

Use "print" or "str" when one serialization method produces volatile output that should be excluded from the snapshot (e.g. objects that embed session-specific file paths or random IDs in their str() representation).

Snapshots are plain text and intended to be committed to version control.

setup_sandbox(files = NULL, temp_base = NULL)

Creates a temporary directory and copies the listed files and/or directories into it, preserving their path structure relative to the project root. Directories are copied recursively. Snapshot files do not need to be listed.

run_in_sandbox(script_path, sandbox = NULL, ...)

Runs an R script inside the sandbox. The working directory is set to the sandbox, but find_root() and snapshot() automatically resolve back to the original project root so snapshots are found correctly.

Returns TRUE invisibly on success, so you can use expect_true(run_in_sandbox(...)) directly in testthat.

cleanup_sandbox(sandbox = NULL, force = TRUE)

Removes the sandbox directory. Omit the argument to clean up the most recently created sandbox.

find_root(start_path = NULL)

Locates the project root by searching upward for a _resultcheck.yml (or legacy resultcheck.yml), .Rproj, or .git marker. Called automatically by snapshot() and setup_sandbox().

Place an empty _resultcheck.yml at your project root to make detection reliable:

# _resultcheck.yml

with_example(code, mismatch = FALSE)

Creates a temporary example project in tempdir(), sets the working directory there while evaluating code, then cleans up automatically.

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License

MIT © Dianyi Yang