README.md

In waldo: Find Differences Between R Objects

waldo

The goal of waldo is to find and concisely describe the difference between a pair of R objects, with the primary goal of making it easier to figure out what’s gone wrong in your unit tests.

waldo::compare() is inspired by all.equal(), but takes additional care to generate actionable insights by:

• Ordering the differences from most important to least important.
• Displaying the values of atomic vectors that are actually different.
• Carefully using colour to emphasise changes (while still being readable when colour isn’t available).
• Using R code (not a text description) to show where differences arise.
• Where possible, comparing elements by name, rather than by position.
• Erring on the side of producing too much output, rather than too little.

Installation

You can install the released version of waldo from CRAN with:

install.packages("waldo")

Comparisons

library(waldo)

When comparing atomic vectors, compare() produces diffs (thanks to diffobj) that highlight additions, deletions, and changes, along with a little context:

• Deletion

r compare(c("a", "b", "c"), c("a", "b"))

• Addition

r compare(c("a", "b"), c("a", "b", "c"))

• Change

r compare(c("a", "b", "c"), c("a", "B", "c"))

• Long vectors with short differences only show local context around changes, not everything that’s the same.

r compare(c("X", letters), c(letters, "X"))

Depending on the relative size of the differences and the width of your console you’ll get one of three displays:

• The default display is to show the vectors one atop the other:

r compare(letters[1:5], letters[1:6])

• If there’s not enough room for that, the two vectors are shown side-by-side:

r options(width = 20) compare(letters[1:5], letters[1:6])

• And if there’s still not enough room for side-by-side, the each element is given its own line:

r options(width = 10) compare(letters[1:5], letters[1:6])

When comparing more complex objects, waldo creates an executable code path telling you where the differences lie:

• Unnamed lists are compared by position:

r compare(list(factor("x")), list(1L))

• Named lists, including data frames, are compared by name. For example, note that the following comparison reports a difference in the class and names, but not the values of the columns.

r df1 <- data.frame(x = 1:3, y = 3:1) df2 <- tibble::tibble(rev(df1)) compare(df1, df2)

• Recursion can be arbitrarily deep:

r x <- list(a = list(b = list(c = list(structure(1, e = 1))))) y <- list(a = list(b = list(c = list(structure(1, e = "a"))))) compare(x, y)

waldo documentation built on Nov. 2, 2023, 5:39 p.m.