Document testing theia

Signed-off-by: Antoine Tremblay <[email protected]>

Author: Antoine Tremblay

.npmignore

@@ -9,4 +9,7 @@ lerna-debug.log
 .nyc_output
 coverage
 .browser_modules
-download
+download
+*ui-spec.ts
+*slow-spec.ts
+test-resources

doc/Developing.md

@@ -122,6 +122,10 @@ Note that we should be able to debug both frontend and backend in one window but
 [this issue](https://github.com/Microsoft/vscode/issues/28817) when trying
 that. tl;dr Some breakpoints don't hit.
 
+## Testing
+
+See the [testing](Testing.md) documentation.
+
 ## tl;dr
 
 To build and run the browser example:

doc/Testing.md

@@ -0,0 +1,38 @@
+# Testing
+
+## Running tests
+
+To run tests on theia run:
+
+`yarn test`
+
+This will run all CI enabled tests.
+
+## Test directory structure
+
+The test directory structure is as follows:
+
+ - `src/node/foo.ts`: Code to be tested.
+ - `src/node/foo.spec.ts`: Unit tests for foo.ts.
+ - `src/node/test/test-helper.ts`: Any mocks, fixture or utility test code
+ goes here.
+ - `src/node/foo.slow-spec.ts`: Any slow running tests such as integration
+ tests should be labeled as such so that they can be excluded.
+ - `src/browser/foo.ui-spec.ts`: UI tests.
+ - `test-resources`: Any resources needed for the tests like configuration
+ files or scripts.
+ - `test-resources/ui`: Resources for UI testing.
+ - `test-resources/slow`: Resources for slow running tests.
+
+## Publishing
+
+### Published test files
+
+Unit tests named as `foo.spec.ts` will be published since they're also for
+documentation purposes.
+
+### Unpublished
+
+ - `*ui-spec.ts`
+ - `*slow-spec.ts`
+ - `test-resources`