Today’s random F# code: one-line unit tests

Sometimes, unit tests are really small – so small that they fit on a single line:

module inside module

Nested modules allow putting unit tests into a hierarchy.

double backtick identifiers

Get nice to read test identifiers by using double backticks.


The test <@ ... @> function is from Unquote – my favourite assertion library. Just write code, no special assertion (fluent) syntax.

%% Operator

We use the %% operator to generate test values from strings. Here, it generates an employee ID. We do this because we use a lot of handwritten IDs in our tests, and this reduces visual noise dramatically in bigger tests.
Ask if you want to know how this works 🙂

Additional notes

FsToolkit.ErrorHandling is not used in this code. But since we use it a lot, I added it to the F# file template.

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Urs Enzler

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By Urs Enzler

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