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JavaScript Debugging in PhpStorm

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    PhpStorm Video Tutorial JavaScript Debugging in PhpStorm
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    With PhpStorm and WebStorm,
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    we can easily debug JavaScript code.
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    Debugging JavaScript code makes use of a Chrome or Firefox
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    extension which is ultimately installed
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    into the selected browser.
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    In the editor, we can set breakpoints.
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    Breakpoints are lines of code in which a debugger will pause
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    execution, and allows us to see what's going on inside our code.
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    We can set breakpoints by clicking the gutter at a specific line
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    of code, or by placing the cursor on a line of code
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    and using the keyboard shortcuts to toggle the breakpoint on or off.
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    Let's add some breakpoints and start the debugger.
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    Once the debugger hits the first breakpoint,
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    a new tool window is opened.
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    From here, we can navigate through the running coded
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    and inspect variables.
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    If we want to pin a variable for inspection,
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    we can add it to the Watches list.
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    This makes it easier to just see the variables we are
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    interested in instead of the long list
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    which the debugger may show you.
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    Using the toolbar buttons or the keyboard shortcuts,
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    we can step through code.
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    The Step Into function follows every function call.
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    Step Over just executes the function call
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    and keeps us in the current piece of code.
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    In the loop we have in our code, the breakpoint
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    is hit in every iteration of the loop.
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    If we are only interested in seeing what's
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    going on in our code for a specific iteration,
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    we can make the breakpoint a conditional breakpoint.
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    Using the Run View Breakpoints menu or the keyboard shortcut,
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    we can specify the condition when the breakpoint is valid.
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    Note that we can also disable the breakpoint until another breakpoint
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    has been hit first, which may be useful in larger code bases.
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    Let's run our code again.
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    As you can see, the breakpoint is only
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    hit when the condition we specified earlier matches.
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    While debugging, it may be useful to be
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    able to alter variables while executing codes.
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    We can do this by selecting the variable we want to change
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    and using the F2 keyboard shortcut to change the value of it.
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    The PhpStorm and WebStorm JavaScript debuggers
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    also feature working with source maps.
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    Consider the example shown on screen.
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    We're using a minified version of jQuery loaded
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    from the Google content delivery network.
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    If we start debugging and step into jQuery code,
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    we will be presented with the full jQuery code instead
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    of the minified version that we were actually using.
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    The debugger does this by following the source
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    maps that are available for jQuery.
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    The debugger will then download the full version of the code,
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    and it can map the minified version of jQuery
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    to the non-minified version which we see in the debugger.
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    Source maps are also used when working with TypeScript
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    or CoffeeScript--two languages that translate into JavaScript.
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    We can set break points in our CoffeeScript or TypeScript code
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    and start a debugging session.
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    Using source maps, the debugger will know how to map the executed
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    JavaScript into the original file, and it will hit the breakpoints
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    that we specified in CofeeScript or TypeScript,
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    even if the browser is actually executing JavaScript code.
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JavaScript Debugging in PhpStorm

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PhpStorm also provides tools for debugging your JavaScript using a Chrome or Firefox extension with the IDE. This lesson shows how to set your breakpoints and walks you through the client-side debug process.

Additional resources: 

Please note that this series covers PhpStorm versions 6 and 7 only.

For the latest documentation (including up-to-date videos), see JetBrains documentation.