```
@Retention(RUNTIME)
@Target(FIELD)
public @interface TrackBean
```
Tracks method calls on any guice bean and records arguments and return values, together with measuring time.
Useful for validating called method arguments and return value (when service called indirectly - by another top-level service). In this sense it is very close to mockito spy (SpyBean), but api is simpler. Tracker collects both raw in/out objects and string (snapshot) version (because mutable objects could change). Raw objects holding could be disabled with keepRawObjects().
Another use-case is slow methods detection: tracker counts each method execution time, and after test could print a report indicating the slowest methods. Or it could be used to simply print all called methods to console with trace() (could be useful during behavior investigations). Another option is to configure a slow method threshold: then only methods above a threshold would be logged with WARN.
Example usage: @TrackBean Tracker<Service> tracker. All calls to Service bean would be tracked. The field might be static.
Manual field initialization is not allowed.
Tracking is implemented with a custom AOP handler which intercepts all bean calls and record them.
Can be used together with mocks, spies or stubs (MockBean, SpyBean, StubBean).
Guicey extension debug (TestGuiceyApp.debug()) enables tracker fields debug: all recognized annotated fields would be printed to console. Also, after each test method it would print performance stats for called methods in all registered trackers.
Individual tracker report could be enabled with printSummary() - will print called methods stats for exact tracker (independent of guicey extension debug option).
By default, tracker re-set after each test method. Use autoReset() to collect tracking data for the entire test.
Limitation: could track only beans, created by guice (due to used AOP). Does not work for HK2 beans.

Since:

11.02.2025

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element	Description
`boolean`	`autoReset`	Note: tracker could be cleared manually with `Tracker.clear()`.
`boolean`	`keepRawObjects`	It is more likely that trackers would be used mostly for "call and verify" scenarios where keeping raw arguments makes perfect sense.
`int`	`maxStringLength`	Required to keep called method toString rendering readable in case of large strings used.
`boolean`	`printSummary`	Note that the summary for all registered trackers is printed when the guicey extension debug option enabled.
`long`	`slowMethods`	Print warnings about methods executing longer than the specified threshold.
`java.time.temporal.ChronoUnit`	`slowMethodsUnit`	Unit for `slowMethods()` threshold value (seconds by default).
`boolean`	`trace`	When enabled, prints called method just after it's execution (with called arguments and returned result).

- Element Detail
  - trace
```
boolean trace
```
    When enabled, prints called method just after it's execution (with called arguments and returned result). Not enabled by default to avoid output mess in case when many methods would be called during test.
    
    Returns:
    
    true to print each method execution
    
    Default:
    
    false
- - slowMethods
```
long slowMethods
```
    Print warnings about methods executing longer than the specified threshold. Set to 0 to disable warnings.
    
    Returns:
    
    slow method threshold (in seconds, by default - see slowMethodsUnit())
    
    Default:
    
    5L
- - slowMethodsUnit
```
java.time.temporal.ChronoUnit slowMethodsUnit
```
    Unit for slowMethods() threshold value (seconds by default).
    
    Returns:
    
    unit for threshold value
    
    Default:
    
    java.time.temporal.ChronoUnit.SECONDS
- - keepRawObjects
```
boolean keepRawObjects
```
    It is more likely that trackers would be used mostly for "call and verify" scenarios where keeping raw arguments makes perfect sense. That's why it's enabled by default.
    Important: method arguments and the result objects state could be mutable and change after or during method execution (and so be irrelevant for tracks analysis). For such cases, the tracker always holds string representations of method arguments and the result (rendered in method execution time).
    It makes sense to disable option if too many method executions appear during the test (e.g., tracker used for performance metrics).
    
    Returns:
    
    true to keep raw arguments and result objects
    
    Default:
    
    true
- - maxStringLength
```
int maxStringLength
```
    Required to keep called method toString rendering readable in case of large strings used. Note that for non-string objects, an object type with identity hash would be shown (not rely on toString because it would be too much unpredictable).
    
    Returns:
    
    maximum length of string in method parameter or returned result
    
    Default:
    
    30
- - autoReset
```
boolean autoReset
```
    Note: tracker could be cleared manually with Tracker.clear().
    
    Returns:
    
    true to reset tracker (remove collected stats) after each test method
    
    Default:
    
    true
- - printSummary
```
boolean printSummary
```
    Note that the summary for all registered trackers is printed when the guicey extension debug option enabled. This option exists to be able to print summary for a single tracker, independent of the debug option.
    The report would be shown after each test method.
    Note that such reports could be built at any time manually with tracker.getStats().render() (or any custom report using tracker.getStats().getMethods()).
    
    Returns:
    
    true to print summary after test
    
    Default:
    
    false

Annotation Type TrackBean

Optional Element Summary

Element Detail

trace

slowMethods

slowMethodsUnit

keepRawObjects

maxStringLength

autoReset

printSummary