covr v3.1.0


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Test Coverage for Packages

Track and report code coverage for your package and (optionally) upload the results to a coverage service like 'Codecov' <> or 'Coveralls' <>. Code coverage is a measure of the amount of code being exercised by a set of tests. It is an indirect measure of test quality and completeness. This package is compatible with any testing methodology or framework and tracks coverage of both R code and compiled C/C++/FORTRAN code.



Build Status AppVeyor Build Status CRAN version

Track test coverage for your R package and view reports locally or (optionally) upload the results to codecov or coveralls.



# For devel version

The easiest way to setup covr on Travis-CI is with usethis.



A coverage report can be used to inspect coverage for each line in your package. Using report() requires shiny.


# If run with no arguments implicitly calls `package_coverage()`

covr also defines an RStudio Addin, which runs report() on the active project. This can be used via the addin menu or by binding the action to a shortcut, e.g. Ctrl-Shift-C.


# if `getwd()` is the package's directory.

# or a package in another directory
cov <- package_coverage("/dir/lintr")

# view results as a data.frame

# zero_coverage() shows only uncovered lines.
# If run within RStudio, `zero_coverage()` will open a marker pane with the
# uncovered lines.

Manual Installation


If you are already using Travis-CI add the following to your project's .travis.yml to track your coverage results over time with Codecov.

  - r-lib/covr

  - Rscript -e 'covr::codecov()'

If you are using Appveyor CI, and are not using Travis-CI at the same time, then you can add the lines below to your project's appveyor.yml:

  - Rscript -e "covr::codecov()"

Don't forget to add covr to the Suggests: field of your package's DESCRIPTION file; possibly also to Remotes: for r-lib/covr.

For further details regarding Appveyor CI integration, also have a look at r-appveyor.

To use a different CI service or call codecov() locally you can set the environment variable CODECOV_TOKEN to the token generated on

Codecov currently has support for the following CI systems (* denotes support without needing CODECOV_TOKEN).

You will also need to enable the repository on Codecov.


Alternatively you can upload your results to Coveralls using coveralls().

  - r-lib/covr

  - Rscript -e 'covr::coveralls()'

For CI systems not supported by coveralls you need to set the COVERALLS_TOKEN environment variable. It is wise to use a Secure Variable so that it is not revealed publicly.

Also you will need to turn on coveralls for your project at


covr supports a few of different ways of excluding some or all of a file.

.covrignore file

A .covrignore file located in your package's root directory can be used to exclude files or directories.

The lines in the .covrignore file are interpreted as a list of file globs to ignore. It uses the globbing rules in Sys.glob(). Any directories listed will ignore all the files in the directory.

Alternative locations for the file can be set by the environment variable COVR_COVRIGNORE or the R option covr.covrignore.

The .covrignore file should be added to your .RBuildignore file unless you want to distribute it with your package. If so it can be added to inst/.covrignore instead.

Function Exclusions

The function_exclusions argument to package_coverage() can be used to exclude functions by name. This argument takes a vector of regular expressions matching functions to exclude.

# exclude print functions
package_coverage(function_exclusions = "print\\.")

# exclude `.onLoad` function
package_coverage(function_exclusions = "\\.onLoad")

Line Exclusions

The line_exclusions argument to package_coverage() can be used to exclude some or all of a file. This argument takes a list of filenames or named ranges to exclude.

# exclude whole file of R/test.R
package_coverage(line_exclusions = "R/test.R")

# exclude lines 1 to 10 and 15 from R/test.R
package_coverage(line_exclusions = list("R/test.R" = c(1:10, 15)))

# exclude lines 1 to 10 from R/test.R, all of R/test2.R
package_coverage(line_exclusions = list("R/test.R" = c(1, 10), "R/test2.R"))

Exclusion Comments

In addition you can exclude lines from the coverage by putting special comments in your source code.

This can be done per line.

f1 <- function(x) {
  x + 1 # nocov

Or by specifying a range with a start and end.

f2 <- function(x) { # nocov start
  x + 2
} # nocov end

The patterns used can be specified by setting the global options covr.exclude_pattern, covr.exclude_start, covr.exclude_end.


Will covr work with testthat, RUnit, etc...

Covr should be compatible with any testing package, it uses tools::testInstalledPackage() to run your packages tests.

Will covr work with alternative compilers such as ICC

Covr now supports Intel's icc compiler, thanks to work contributed by Qin Wang at Oracle.

Covr is known to work with clang versions 3.5+ and gcc version 4.2+.

If the appropriate gcov version is not on your path you can set the appropriate location with the covr.gcov options. If you set this path to "" it will turn off coverage of compiled code.

options(covr.gcov = "path/to/gcov")

How does covr work?

covr tracks test coverage by modifying a package's code to add tracking calls to each call.

The vignette vignettes/how_it_works.Rmd contains a detailed explanation of the technique and the rationale behind it.

You can view the vignette from within R using

vignette("how_it_works", package = "covr")

Why can't covr run during R CMD check

Because covr modifies the package code it is possible there are unknown edge cases where that modification affects the output. In addition when tracking coverage for compiled code covr compiles the package without optimization, which can modify behavior (usually due to package bugs which are masked with higher optimization levels).

Alternative Coverage Tools

Functions in covr

Name Description
zero_coverage Provide locations of zero coverage
package_coverage Calculate test coverage for a package
to_cobertura Create a Cobertura XML file
trace_calls trace each call with a srcref attribute
system_check Run a system command and check if it succeeds.
coverage_to_list Convert a coverage dataset to a list
coveralls Run covr on a package and upload the result to coveralls
exclusions Exclusions
file_coverage Calculate test coverage for sets of files
covr-package covr: Test coverage for packages
shine Deprecated Functions These functions are Deprecated in this release of covr, they will be marked as Defunct and removed in a future version.
function_coverage Calculate test coverage for a specific function.
codecov Run covr on a package and upload the result to
key Generate a key for a call
new_counter initialize a new counter
percent_coverage Provide percent coverage of package
clear_counters clear all previous counters
value Retrieve the value from an object
code_coverage Calculate coverage of code directly
count increment a given counter
report Display covr results using a standalone report
print.coverage Print a coverage object
system_output Run a system command and capture the output.
tally_coverage Tally coverage by line or expression
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