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Compare two captured environments

Source: R/profile_extra.R
environment_diff.Rd

Reports what changed between the environment captured by one run and another: the R version, the platform, and every package whose version differs, was added, or disappeared.

Usage

environment_diff(a, b)

Arguments

a, b

Environment records from capture_environment(), or whole manifests containing an environment element.

Value

A list of class bricklayer_env_diff: identical (logical), r_version (a length-2 character vector when they differ, else NULL) , platform (likewise), and packages (a data frame of package, a, b, change, where change is "added", "removed" or "changed") .

Details

This is the question a failed reproduction actually raises. A manifest records the environment; comparing two manifests by eye across a few hundred packages does not scale, and the one line that matters – a dependency that moved a minor version – is exactly what gets missed.

See also

capture_environment(), make_manifest()

Examples

a <- capture_environment()
b <- a

# An environment matches itself.
environment_diff(a, b)$identical
#> [1] TRUE

# Stage a moved dependency and a removed one.
if (length(b$packages)) {
  nm <- names(b$packages)[1]
  b$packages[[nm]] <- "0.0.0"
  environment_diff(a, b)$packages
}
#>   package     a     b  change
#> 1      R6 2.6.1 0.0.0 changed

# Whole manifests are accepted, not just the environment block.
m <- make_manifest(list(run = "demo"))
environment_diff(m, m)$identical
#> [1] TRUE