Add how to run unit tests (#171)

Add how to rebuild a package, how to run unit tests, and how to limit directories to run unit tests
tier4/autoware.iv#1545 tier4/autoware.iv#1924

docs/developer_guide/UnitTestGuideline.md

@@ -1,3 +1,28 @@
 # TierIV Unit Test Guideline
 
-See [confluence page](https://tier4.atlassian.net/wiki/spaces/AIP/pages/1400045921/T4)
+## How to run unit tests
+
+You may modify the code before running unit tests. This is how to rebuild the package you modified.
+
+```sh
+colcon build --symlink-install --cmake-args -DCMAKE_BUILD_TYPE=Release --packages-up-to <package name>
+```
+
+`package name` must be the name of a package that contains package.xml
+
+Use the commands below to run unit tests. `--packages-skip-test-passed` can be used to ignore test cases that already passed.
+
+```sh
+source install/setup.bash
+colcon test --event-handlers console_cohesion+ --packages-skip-test-passed
+```
+
+If you would like to run unit tests in a specific directory, you can use the `--base-paths` option. For example, if you would like to run unit tests in autoware.iv, you can run
+
+```sh
+colcon test --event-handlers console_cohesion+ --base-paths src/autoware/autoware.iv --packages-skip-test-passed
+```
+
+## How to write unit tests
+
+See [confluence page](https://tier4.atlassian.net/wiki/spaces/AIP/pages/1400045921/T4) for the details.