* eng: add support for snapshot tests This adds Jest-like support for snapshot testing. Developers can do something like: ```js await assertSnapshot(myComplexObject) ``` The first time this is run, the snapshot expectation file is written to a `__snapshots__` directory beside the test file. Subsequent runs will compare the object to the snapshot, and fail if it doesn't match. You can see an example of this in the test for snapshots themselves! After a successful run, any unused snapshots are cleaned up. On a failed run, a gitignored `.actual` snapshot file is created beside the snapshot for easy processing and inspection. Shortly I will do some integration with the selfhost test extension to allow developers to easily update snapshots from the vscode UI. For #189680 cc @ulugbekna @hediet * fix async stacktraces getting clobbered * random fixes * comment out leak detector, for now * add option to snapshot file extension
Unit Tests
Run (inside Electron)
./scripts/test.[sh|bat]
All unit tests are run inside a Electron renderer environment which access to DOM and Nodejs api. This is the closest to the environment in which VS Code itself ships. Notes:
- use the
--debugto see an electron window with dev tools which allows for debugging - to run only a subset of tests use the
--runor--globoptions - use
yarn watchto automatically compile changes
For instance, ./scripts/test.sh --debug --glob **/extHost*.test.js runs all tests from extHost-files and enables you to debug them.
Run (inside browser)
yarn test-browser --browser webkit --browser chromium
Unit tests from layers common and browser are run inside chromium, webkit, and (soon'ish) firefox (using playwright). This complements our electron-based unit test runner and adds more coverage of supported platforms. Notes:
- these tests are part of the continuous build, that means you might have test failures that only happen with webkit on windows or chromium on linux
- you can run these tests locally via yarn
test-browser --browser chromium --browser webkit - to debug, open
<vscode>/test/unit/browser/renderer.htmlinside a browser and use the?m=<amd_module>-query to specify what AMD module to load, e.gfile:///Users/jrieken/Code/vscode/test/unit/browser/renderer.html?m=vs/base/test/common/strings.testruns all tests fromstrings.test.ts - to run only a subset of tests use the
--runor--globoptions
Note: you can enable verbose logging of playwright library by setting a DEBUG environment variable before running the tests (https://playwright.dev/docs/debug#verbose-api-logs)
Run (with node)
yarn test-node --run src/vs/editor/test/browser/controller/cursor.test.ts
Coverage
The following command will create a coverage folder in the .build folder at the root of the workspace:
OS X and Linux
./scripts/test.sh --coverage
Windows
scripts\test --coverage