azure/Documentation/Debugging.md

Microsoft Azure Client Library for node

Different ways to debug azure-sdk-for-node

## Using console.log()
This is always handy and is guaranteed to work.
It is a good practice to use util.inspect() to dump well formatted objects.
In your script:
```
var util = require('util');
. . .
console.log(">>>>>>>>>>>>>> Some Identifier   " + util.inspect(some_object, {depth: null}));
. . .
```
Providing **{depth: null}** is optional. By default, it will dump object upto 3 levels deep. Setting depth  to null will dump the complete object.

## Using Visual Studio
The Visual Studio plugin for node.js can be downloaded from [here](https://github.com/Microsoft/nodejstools/releases).

### Setting up the project
* Open the **nodeSDK.sln** file present at the root of the cloned repo.
* Set the Tab size and Indentation to 2 spaces by going to 
  * Tools --> Options --> TextEditor --> Node.js --> Tabs --> [Tab size: 2, Indent size: 2]
  * Tools --> Options --> TextEditor --> Javascript --> Tabs --> [Tab size: 2, Indent size: 2]

### For debugging the tests:
  * From the menu bar go to Project --> Properties and set the environment variables required for running tests.
    * The list of environment variables can be found over [here](./EnvironmentVariables.md)
    * If the need arises to add a new environment variable for tests please update the [Documentation](EnvironmentVariables.md) to keep the list current
    * Visual Studio can also be opened from **"Visual Studio Debugger Cmd Prompt"** usually located at "C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\Tools\Shortcuts\Developer Command Prompt for VS2013.lnk" to set the environment variables. Then open the .sln file from the prompt.
  * In the Solution Explorer, click on a test that needs to be debugged. For example: "azure-sdk-for-node\test\services\storageManagement\storageManagementClient-tests.js"
  * In the **Properties** pane select **"Mocha"** as the Test Framework. Save All the changes. 
  * The tests shall be seen in the "Test Explorer". Right Click on any Test and Select "Debug Selected Test".
* **Note:** If the test file has any errors then you might not see the tests in the TestExplorer. In the Properties pane select **ExportRunner** as the test framework and save the solution. You will see the error in the output pane. Once the errors are resolved change the test framework back to **Mocha** in the Properties pane for that test file. When you save the solution, you should see your tests in the test explorer.
  * You can also run ```npm -s run-script jshint``` in the cmd prompt from the root of the repo to find errors if any. 

##  Using node inspector
This will open a debugging session in a browser (chrome or opera). It is super easy to use.
Steps to get it working:

* ```npm install -g node-inspector```
* Assuming this is being executing in the cmd prompt from the root directory of the cloned repo "azure-sdk-for-node/"
  *   ```node-debug some-test-script-that-calls-your-service.js```
* A browser (Chrome/Opera) should pop up, or it can be manually browsed at this url - http://127.0.0.1:8080/debug?port=5858
* Now breakpoints can be set at desired location.
* It may happen that files with extension "._js" are not seen initially in the left pane. Please set a break point anywhere in lib\azure.js and keep on pressing "F10". After some time, files with extension "_.js" can be seen. Breakpoints can now be set at desired line in "*._js" file.

### For debugging tests:
Please follow the below mentioned steps for the debugger to accept breakpoints set in your test file:
* In the file azure-sdk-for-node/scripts/unit.js
```
modify the last line 
from  - require('../node_modules/mocha/bin/mocha');
to    - require('../node_modules/mocha/bin/_mocha');
```
* set a breakpoint at runTest() method of mocha's runner.
In the file "azure-sdk-for-node\node_modules\mocha\lib\runner.js" in the "runTest()" method around Line 378.
  * **Note**: "node_modules" directory is not a part of "azure-sdk-for-node" repository.  If the **"node_modules"** directory or the **"mocha"** directory inside **"node_modules"** directory is not present, then ```npm install``` needs to be executed from the root directory of the cloned "azure-sdk-for-node" repo.
```
Runner.prototype.runTest = function(fn){
  var test = this.test
    , self = this;

  if (this.asyncOnly) test.asyncOnly = true;

  try {
    test.on('error', function(err){
      self.fail(test, err);
    });
    test.run(fn); <<<<<<<<<<<<<<<<<<<<<<<-------- set a breakpoint here
  } catch (err) {
    fn(err);
  }
};
```
* Set a breakpoint in your test which should be located under "azure-sdk-for-node/test/commands" directory