How can the code coverage data from Flutter tests be displayed?

Question

I'm working on a Flutter app using Android Studio as my IDE. I'm attempting to write tests and check the code coverage but I can't work out how to view the data in the IDE or any other application.

By running flutter test --coverage, a coverage report seems to be generated into a file /coverage/lcov.info. That file looks something like this:

SF:lib\data\Customer.g.dart
DA:9,2
DA:10,2
DA:11,2
DA:12,2
DA:13,2
DA:20,0
DA:21,0
DA:22,0
DA:23,0
DA:24,0
...

Looking at the file it seems to have a list of my project files with line by line coverage data. Is there a way to view this information in Android Studio?

Answer 1

You can also install lcov and convert the lcov.info file to HTML pages and then see the result in the browser with sorting option.

1. Installation

1.1. Installing in Ubuntu

sudo apt-get update -qq -y
sudo apt-get install lcov -y

1.2. Installing in Mac

brew install lcov

2. Run tests, generate coverage files and convert to HTML

flutter test --coverage
genhtml coverage/lcov.info -o coverage/html

Note This way you can add it to circleci artifacts and coveralls as well.

Answer 2

This is what you want to run to see tests coverage in your browser on macOS

flutter test --coverage
genhtml coverage/lcov.info -o coverage/html
open coverage/html/index.html

Answer 3

You can view the code coverage generated by flutter with the Atom editor.
You just need to install the Dart and lcov-info packages.

Then you load your project folder and press Ctrl+Alt+c, coverage will be displayed with a summary of the whole projects coverage and also with specific line highlighting.

There doesn't appear to be any plugin for Android studio which does this as of yet.