# serverless-plugin-powertools ## Variable Resolvers For good use cases check out `tests/unit/lib/configuration/variables`. Current list of provided resolvers: - `castToBool` - `castToInteger` - `castToString` - `castToBoolOrContinue` - `castToIntegerOrContinue` - `castToStringOrContinue` - `negateBool` - `negateBoolOrContinue` - `isTruthy` - `isFalsy` ## To what end? Currently this plugin exposes the following variable resolvers that offer type casting, boolean operations, and conditional continuations. You can use them to ensure that external values from the environment, CloudFormation outputs, and external parameter stores are cast to the appropriate value. One important use case is defining bucket sizes through the environment or an external parameter that should ideally be an integer once rendered. Simple conditional rendering support is provided through `isTruthy` and `isFalsy`. Example: ```yaml custom: something: true boolyStuff: makeSureThisIsBooly: ${castToBool('yes')} doTheOppositeOfFalse: ${negateBool('false')} doTheOppositeOfSomething: ${negateBool(${self:custom.something})} stringyStuff: makeSureThisIsStringy: ${castToString(1234)} integeryStuff: makeSureThisIsInteger: ${castToInteger('300')} continuationSupport: ifThisIsntAnIntegerThenUseDefault: ${castToIntegerOrContinue('eggsammich'), 0} noContinuationSupport: ifThisIsntAnIntegerThenUseDefault: ${castToIntegerOrContinue('42'), 0} conditionalAwesomeness: thisOrThat: ${isTruthy('true'), 'this'}${isTruthy('false'), 'that'} ``` Output: ```yaml custom: something: true boolyStuff: makeSureThisIsBooly: true doTheOppositeOfFalse: true doTheOppositeOfSomething: false stringyStuff: makeSureThisIsStringy: '1234' integeryStuff: makeSureThisIsInteger: 300 continuationSupport: ifThisIsntAnIntegerThenUseDefault: 0 noContinuationSupport: ifThisIsntAnIntegerThenUseDefault: 42 conditionalAwesomeness: thisOrThat: this ```