Add onCacheError option

[slukes]

Please check if the PR fulfills these requirements

• Followed the Contributing guidelines.

• Tests for the changes have been added (for bug fixes/features) with 100% code coverage.

• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

This PR addresses:

#643
#588
#51

By re-adding an option that existed in caching.js to 'ignore' cache errors but was removed during the migration to typescript / promises.

This is useful to applications that are using a distant cache store, to enable to application to continue to work, even when the cache backend is down.

[jaredwray]

@slukes - I would rather not have another config on this and since it is cache should we just add in EventEmitter3 and emit an error when it goes to a catch?

[slukes]

@slukes - I would rather not have another config on this and since it is cache should we just add in EventEmitter3 and emit an error when it goes to a catch?

Hello @jaredwray I'm not sure how this is going to work! I've created a ticket on our team backlog to dig into this further in the next couple of weeks

[jaredwray]

@slukes - what I am saying is that instead of doing an ignoreErrors property in the cache manager what we can do is enable you to do this instead:

import { caching } from 'cache-manager';

const cache = await caching('memory', {
  max: 100,
  ttl: 10 * 1000 /*milliseconds*/,
});

cache.on('error', (error) = > {
     console.log(error);
});

This would use events to emit an error and by default we would make all methods catch errors and not throw. This gives the resiliency shown in keyv that many love.

Would that work for you?

[slukes]

@jaredwray thanks to the work of @AdrienDoctolib we now have something that is working how you suggested. Please let us know your feedback.

We have tested in our application and all is well 👍

[jaredwray]

@AdrienDoctolib and @slukes looks like we are getting an error on compile time:

[slukes]

@AdrienDoctolib and @slukes looks like we are getting an error on compile time:

Sorry about that - fixed!

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 90.90909% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 98.96%. Comparing base (511e426) to head (140864b).

Files	Patch %	Lines
src/multi-caching.ts	80.00%	4 Missing ⚠️

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Additional details and impacted files

@@             Coverage Diff             @@
##              main     #646      +/-   ##
===========================================
- Coverage   100.00%   98.96%   -1.04%     
===========================================
  Files            5        5              
  Lines          365      387      +22     
  Branches        89       93       +4     
===========================================
+ Hits           365      383      +18     
- Misses           0        4       +4     

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