Today I Learned

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3 posts by mattpolito @mattpolito

Using pessimistic gem version to catch betas

The trouble with pessimistic (~>) versioning is that it still won’t catch pre-release library versions… or will it.

It actually can allow ‘beta’ versions by adding an ‘x’ to the version you’d like to catch.

gem "rails", "~> 5.x"

Since ‘beta’ versions (5.0.0.beta3) actually register as higher than 5.0.0, the pessimistic operator will not catch the beta version. Gem versioning shows any version with a letter as ‘pre-release’ which is how beta3, rc1, alpha versions work.

Using the ‘x’ as a wildcard will allow pre-release gem versions to be caught.