topcoder-platform/expression-evaluator

This is a very simple version of a compiler expression evaluation. It can be used for parsing expressions without introducing the risk of script injection via `eval` method.

Expression Evaluator

This is a very simple version of a compiler expression evaluation. It can be used for parsing expressions without introducing the risk of script injection via eval method.

Submission

For now we always should include updated prebuilt code into the repository. As for now for quick development we include this npm module directly as git repository.

To do so, run before commit:

npm run prepublish

Commands

• npm run clean - Remove lib/ directory
• npm test - Run tests with linting and coverage results.
• npm run lint - Run ESlint with airbnb-config
• npm run build - Babel will transpile ES6 => ES5 and minify the code.
• npm run prepublish - Hook for npm. Do all the checks before publishing your module.

License

MIT © Topcoder Inc.

expression-evaluator's Issues

Need to support null and undefined value checks

As of now variableA == null or variableA == undefined does not work as expected. We need to support both of these cases. And it would be great if we can support simply variableA to check for non null and not undefined value for the specified variable.

@maxceem @RishiRajSahu fyi

operator 'contains' should find object inside the array which is a property of another object

When we search for an object inside object property it is always false and cannot find an object.

I've added one more test which is failing https://github.com/topcoder-platform/expression-evaluator/blob/dev/src/index.spec.js#L755-L758

Fix handling of undefined value for hasLength operator

As of now hasLength(null) == 0 returns true while hasLength(undefined) == 0 returns false. We need keep the behaviour for both null and undefined same for operator hasLength either it should return true as practically the array value passed to the operation in such case does not have any item in it or it should return false as theoretically a null or undefined value does not have any length.

@maxceem what do you think?