60 lines
2.7 KiB
Markdown
60 lines
2.7 KiB
Markdown
|
# Debugging Angular
|
||
|
|
|
||
|
|
The Angular project has comprehensive unit tests for the core packages and the tools.
|
||
|
|
The core packages are tested both in the browser (via Karma) and on the server (via Node.js).
|
||
|
|
|
||
|
|
## Debugging in Karma
|
||
|
|
|
||
|
|
Run the unit tests as normal using via the `./test.sh` script. For example:
|
||
|
|
|
||
|
|
```bash
|
||
|
|
./test.sh browserNoRouter
|
||
|
|
```
|
||
|
|
|
||
|
|
Once the initial build has completed and the Karma server has started up, you can go to the
|
||
|
|
Chrome browser that is automatically opened, usually pointing to `http://localhost:9876`.
|
||
|
|
The script will sit watching for code changes, recompiling the changed files and triggering
|
||
|
|
further runs of the unit tests in the browser.
|
||
|
|
|
||
|
|
In this browser there is a "DEBUG" link (in the top right corner). Clicking this link will
|
||
|
|
open up a new tab that will run the unit tests and will not timeout, giving you time to
|
||
|
|
step through the code.
|
||
|
|
|
||
|
|
Open up this tab's developer console to access the source code viewer where you can set
|
||
|
|
breakpoints and interrogate the current stack and variables.
|
||
|
|
|
||
|
|
It is useful to focus your debugging on one test at a time by changing that test to be
|
||
|
|
defined using the `fit(...)` function, rather than `it(...)`. Moreover it can be helpful
|
||
|
|
to place a `debugger` statement in this `fit` clause to cause the debugger to stop when
|
||
|
|
it hits this test.
|
||
|
|
|
||
|
|
## Debugging in Node
|
||
|
|
|
||
|
|
Run the unit tests as normal using the `./test.sh` script, but add the `--debug` flag to
|
||
|
|
the command. For example:
|
||
|
|
|
||
|
|
```bash
|
||
|
|
./test.sh node --debug
|
||
|
|
```
|
||
|
|
|
||
|
|
Once the initial building has completed, the script will watch for code changes, recompiling
|
||
|
|
and running the unit tests via a tool call `cjs-jasmine`. Due to the `--debug` flag, each
|
||
|
|
test run will create a debugging server listening on a port (such as 9229), which can be
|
||
|
|
connected to by a debugger.
|
||
|
|
|
||
|
|
You can use Chrome as the debugger by navigating to `chrome://inspect` then clicking the
|
||
|
|
"Open dedicated DevTools for Node" link. This will open up a Developer console, which will
|
||
|
|
automatically connect to the debugging server.
|
||
|
|
|
||
|
|
It is useful to focus your debugging on one test at a time by changing that test to be
|
||
|
|
defined using the `fit(...)` function, rather than `it(...)`. Moreover it can be helpful
|
||
|
|
to place a `debugger` statement in this `fit` clause to cause the debugger to stop when
|
||
|
|
it hits this test.
|
||
|
|
|
||
|
|
**Problem with node 6:** at the time of writing, the node process does not tell the Chrome
|
||
|
|
debugger when it has completed, and so the debugger is not able to automatically disconnect
|
||
|
|
from listening to the debugging server. To solve this, just close the developer tools window
|
||
|
|
after each run of the unit tests, before making changes to the code. This is fixed in node 8
|
||
|
|
and may be backported to node 6. This issue is tracked in
|
||
|
|
https://github.com/nodejs/node/pull/12814#issuecomment-309908579.
|