Coverage

Coverage provides coverage data collection, manipulation, and formatting for Dart.

Tools

collect_coverage collects coverage JSON from the Dart VM Observatory. format_coverage formats JSON coverage data into either LCOV or pretty-printed format.

Install coverage

pub global activate coverage

Consider adding the pub global run executables directory to your path. See Running a script from your PATH for more details.

Collecting coverage from the VM

dart --observe=NNNN script.dart
pub global run coverage:collect_coverage --port=NNNN -o coverage.json --resume-isolates

or if the pub global run executables are on your PATH,

collect_coverage --port=NNNN -o coverage.json --resume-isolates

If collect_coverage is invoked before the script from which coverage is to be collected, it will wait until it detects a VM observatory port to which it can connect. An optional --connect-timeout may be specified (in seconds). The --wait-paused flag may be enabled, causing collect_coverage to wait until all isolates are paused before collecting coverage.

Collecting coverage from Dartium

dartium --remote-debugging-port=NNNN
# execute code in Dartium
pub global run coverage:collect_coverage --port=NNNN -o coverage.json

or if the pub global run executables are on your PATH,

collect_coverage --port=NNNN -o coverage.json

As noted above, collect_coverage may be invoked before Dartium, in which case it will wait until it detects a Dartium remote debugging port, up to the (optional) timeout. Note that coverage cannot be run against a Dartium instance launched from Dart Editor, since the editor makes use of Dartium's remote debugging port.

Formatting coverage data

pub global run coverage:format_coverage --package-root=app_package_root -i coverage.json

or if the pub global run exectuables are on your PATH,

format_coverage --package-root=app_package_root -i coverage.json

where app_package_root is the package-root of the code whose coverage is being collected. If --sdk-root is set, Dart SDK coverage will also be output.