My first post on this blog back in March 2012 related to Simulated Breakpoints, a developer console feature enabling a head dump to be captured when code execution hit a specified line(s) of Apex script. Whilst not comparable to the power of breakpoints in debugging with other languages, Simulated Breakpoints was a definitely step forward for Force.com development, but I suspect this still remains an unused feature, with System.debug() statements being used instead. I don’t believe too many developers are juggling the Force.com IDE and Developer Console, which is unfortunate as the latter provides features and metrics not supported by the IDE.

Checkpoints.
In Summer ’13 Simulated Breakpoints are now termed Checkpoints and can be set on lines of Apex script in the same way using the code editor (now with syntax highlighting) within the Developer Console. In addition to capturing a heap dump, Apex script or SOQL query Execution Actions can be added which run when code execution hits the Checkpoint. Very useful in determining state of the execution context and in particularly in debugging data related issues.

In the screenshot below we can see the new Developer Console UI for Summer 13, the Checkpoints tab and the definition of an example SOQL query Execution Action which will run when the Checkpoint is hit.

In the screenshot below we can see the result, when the Heap Dump log statement is double-clicked a Checkpoint tab is revealed with subtabs that show the Heap Dump itself, plus the result of defined Execution Actions. Note, I was unable to open the Checkpoint results where an Apex Execution Action was defined, from the log activity it does appear to run as an Execute Anonymous block, but it isn’t clear if the user context is the debugging user or the running user.