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RSpec 3 allows chaining multiple expectations

When you are using lambdas in RSpec to assert certain changes of a call, you know this syntax:

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expect { playlist.destroy }.to change { Playlist.count }.by(-1)

While you can define multiple assertions through multiple specs, you may not want to do so, e.g. for performance or for the sake of mental overhead.

RSpec allows chaining expectations simply by using and.

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expect { playlist.destroy } .to change { Playlist.count }.by(-1) .and change { Video.count }.by(0)

The above example will call playlist.destroy only once, but test both assertions.

In addition to and, RSpec also offers or which means that only one condition needs to be satisfied. Example from the docs:

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expect(light.color) .to eq("green") .or eq("yellow") .or eq("red")
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Arne Hartherz
Last edit:
2 months ago
by Thomas Eisenbarth
Keywords:
compound, expectations
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Posted by Arne Hartherz to makandra dev
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