ng build gives an error because of regExp

Question

i have regExp in constants:

export const Constants = {
    QUERY_PARAM_CONFIG: {
        REGEX: /\+/gi,
        REGEX_ENCODED: /%2B/g
    }
};

but when i run ng build i get an error:

ERROR in app\app.module.ts(58,21): Error during template compile of 'AppModule'
  Expression form not supported in 'Constants'
    'Constants' contains the error at app\configuration\constants.ts.

npm build script:

ng build --prod --output-hashing none --sourcemaps=true

any ideas?

Answer 1

The regex literals are not supported by AOT. See the list of supported syntax.

In order to make it work transform your regex to something supported e.g. string:

const before = /\+/gi, // before, could be the same as below

const after = { re: '\\+', flags: 'gi' }
const canBeUsedAs = new RegExp(after.re, after.flags);

By this you can still pass the meaning of the RegExp and create one on the fly whenever you need them in the runtime