when should I use ConfigureAwait(true)

Question

Has anyone come across a scenario for using ConfigureAwait(true)? Since true is the default option I cannot see when would you ever use it.

Answer 1

One possibility I can see is if you're writing code in a library and you want to allow your callers to decide whether it's appropriate to continue on the original context¹ (although I'd usually argue for never continuing on the original context from within library code)

Your caller will either pass a bool parameter or set some configuration value, and so you will not know until runtime what the correct argument value is.

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This is the general type of answer for APIs such as this that have a no-args variant and a variant with a single argument, where the no-args variant is documented as "the same as the single argument variant with well-known value x" - if you won't know until runtime what the correct value to pass is, then you should just call the single argument variant with the correct runtime value.

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¹ E.g. your caller is also supplying a delegate. Your caller will know (and can decide) whether that delegate needs to be back on the original context or not.