62 ms·

Chiming in on this point: > In this case, other libraries... but I honestly don't see the difference. Libraries and services have APIs. They either work or the

by Yoric 4y ago

Chiming in on this point: > In this case, other libraries... but I honestly don't see the difference. Libraries and services have APIs. They either work or they don't. Services have the additional complexity of network failures and runtime errors, but these are things that can be dealt with and tested in the primary project. In my personal experience, there are considerable differences. From the top of my head: 1. Typically, your libraries don't shift under you without any action from your part. External services do. 2. In CI, you can either use the external service (which may require piercing holes in your CI's security and may break due to no change of your part), replicate it (which is more stable but can be extremely painful and resource-consuming) or mock it (which is even more stable but limits the realism of your tests). 3. And of course, as you mention, services have all sorts of failure modes, including but not limited to network failures. Normally, your tests should cover all these failure modes. I don't think I've ever seen code that does that, in part because service errors are very often notoriously under-documented. YMMV

latchkey 4y ago
> 1. Typically, your libraries don't shift under you without any action from your part. External services do. External services should have versioning, just like libraries. > 2. ... They don't need to be 'or'. > 3. ... I write tests for this. If I'm using a networking library/function (let's use `fetch` as an example) to talk to a 3rd party external service, I write a wrapper around it to deal with error cases. I then write tests for that wrapper. Anything that uses that wrapper is then inherently tested at the networking level. I then write tests for my own code which uses the wrapper, to deal with the thrown exceptions and how that code should deal with them (retries, throw again, etc). You don't do that? Do you just assume that all calls to `fetch` succeed?

by Yoric 4y ago

latchkey 4y ago

> 1. Typically, your libraries don't shift under you without any action from your part. External services do. External services should have versioning, just like libraries. > 2. ... They don't need to be 'or'. > 3. ... I write tests for this. If I'm using a networking library/function (let's use `fetch` as an example) to talk to a 3rd party external service, I write a wrapper around it to deal with error cases. I then write tests for that wrapper. Anything that uses that wrapper is then inherently tested at the networking level. I then write tests for my own code which uses the wrapper, to deal with the thrown exceptions and how that code should deal with them (retries, throw again, etc). You don't do that? Do you just assume that all calls to `fetch` succeed?