diff --git a/README.md b/README.md index e15be98..89613f7 100644 --- a/README.md +++ b/README.md @@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/). For a steady stream of TILs from a variety of rocketeers, checkout [til.hashrocket.com](https://til.hashrocket.com/). -_652 TILs and counting..._ +_653 TILs and counting..._ --- @@ -255,6 +255,7 @@ _652 TILs and counting..._ - [Splat Arguments To A Function](javascript/splat-arguments-to-a-function.md) - [Spread The Rest With ES6](javascript/spread-the-rest-with-es6.md) - [String Interpolation With Template Literals](javascript/string-interpolation-with-template-literals.md) +- [Test Coverage Stats With Jest](javascript/test-coverage-stats-with-jest.md) - [Throttling A Function Call](javascript/throttling-a-function-call.md) - [Timing Processes](javascript/timing-processes.md) - [Transforming ES6 and JSX With Babel 6](javascript/transforming-es6-and-jsx-with-babel-6.md) diff --git a/javascript/test-coverage-stats-with-jest.md b/javascript/test-coverage-stats-with-jest.md new file mode 100644 index 0000000..865e431 --- /dev/null +++ b/javascript/test-coverage-stats-with-jest.md @@ -0,0 +1,24 @@ +# Test Coverage Stats With Jest + +Jest is a delightful tool for JavaScript testing from Facebook. As your +project evolves and you add tests (or perhaps choose to not add tests) you +may wonder what kind of test coverage you have. What is the overall +coverage? Which files are well covered and which are seriously lacking? + +Use the `--coverage` flag to get this information. + +```bash +$ jest --coverage +``` + +After running all of your tests a table will be output to the terminal with +a list of files and their respective coverage percentages in terms of +statement, branch, function, and line coverage. + +``` +---------------------------|----------|----------|----------|----------|----------------| +File | % Stmts | % Branch | % Funcs | % Lines |Uncovered Lines | +---------------------------|----------|----------|----------|----------|----------------| +``` + +This can help guide you to what parts of your app may need more testing.