fix(utils): Fix reactivation authenticator not evicting; refactor & test

[marfavi]

Summary

This pull request introduces changes to the reactivation_authenticator.dart file, including a bug fix. The utility class mutex.dart is also rewritten (but unused), and a new utility class throttler.dart is added. All these files have corresponding tests.

Closes #416 Closes #492

Bug fixes

Fixed a bug where the user was not evicted if the token was expired. The method ReactivationAuthenticator.authenticate() now checks the request body type against the LoginDto type to check if a failed request was an attempt to refresh the token; if it was, we stop execution to avoid infinite recursion. This change fixes #492.

Utility classes

• Rewritten Mutex utility class and added tests for it.
• Added new utility class Throttler. This class allows you to limit the rate at which some tasks are executed by ensuring that only one task can run through the Throttler at any given time. If a task is already running through the Throttler, an attempt to throttle a task will instead return the currently running task.
• Both classes utilize fpdart's Task class to support asynchronous operations, alongside other fpdart utilities such as Option, Unit, and the bool.match() extension where appropriate.
• Both classes are tested with full coverage.

ReactivationAuthenticator

The ReactivationAuthenticator class has been rewritten to use the new Throttler class instead of the Mutex class. The ReactivationAuthenticator class has also been simplified and cleaned up.

For example, we no longer needs to maintain internal state about whether we should throttle a token refresh attempt, and we don't need to check whether a Mutex is locked, since the Throttler class handles both cases for us.

The class is also tested with full coverage. This change closes #416.

Service locator

• Moved the initialization of http clients, interceptors, and authenticators to a separate function initHttp() in service_locator.dart.
• In service_locator.dart, the ReactivationAuthenticator class is now registered in two steps:
  1. The ReactivationAuthenticator is registered as a singleton using the constructor ReactivationAuthenticator.uninitialized().
  2. The method ReactivationAuthenticator.initialize() is called to initialize the ReactivationAuthenticator with the AccountRemoteDataSource to use.

[sonarcloud[bot]]

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[codecov[bot]]

Codecov Report

Merging #429 (dfd6165) into develop (2bb7da1) will increase coverage by 4.74%. The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop     #429      +/-   ##
===========================================
+ Coverage    71.44%   76.19%   +4.74%     
===========================================
  Files          114      115       +1     
  Lines         1194     1218      +24     
===========================================
+ Hits           853      928      +75     
+ Misses         341      290      -51     

Flag	Coverage Δ
unittests	76.19% <100.00%> (+4.74%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
lib/utils/mutex.dart	100.00% <100.00%> (+100.00%)	:arrow_up:
lib/utils/reactivation_authenticator.dart	100.00% <100.00%> (+100.00%)	:arrow_up:
lib/utils/throttler.dart	100.00% <100.00%> (ø)