undefined facts

[calpa]

When the user removed the input value, the value (fact) will becomes undefined.

Which throws an error according to the following code...

if (typeof this.value === 'undefined' && typeof this.calculationMethod === 'undefined') {
  throw new Error('facts must have a value or method')
}

Link: https://github.com/CacheControl/json-rules-engine/blob/master/src/fact.js#L29

One possible solution is to pass allowUndefinedFacts: true to the Fact Class.

Related issues: #111

[saswat3115]

even if u pass allowUndefinedFacts: true this also fails.

[saswat3115]

Following changes need to be done to fix this
allowUndefinedFacts are not being passed to fact.js file

changes in fact.js

changes in almanac.js

[CacheControl]

One point of clarity: allowUndefinedFacts controls the fact identifier, whereas the error being thrown above is the fact value:

{
  fact: 'my-fact',  <--- fact identifier, throws if undefined unless allowed via allowUndefinedFacts
  operator: 'equal',
  value: undefined, <---- fact value
}

I agree it's silly to require fact values to not be undefined - it just forces everyone to set their fact values to something else (null, false, etc). It also prevents valid use of equal/notEqual with undefined.

I've opened #236 to fix this, it is published as 5.1.0-rc1 I'll merge it in the next few days. @saswat3115 @calpa could you try installing this RC and validate it fixes your issue please?

[CacheControl]

This is now published as 5.3.0

[gunjan-it-engg]

const engine = new Engine(rules, { allowUndefinedFacts: true });