Migrating - aMarCruz/jscc GitHub Wiki

jscc v1.0 is a complete rewrite. It is using TypeScript 3.0 and one enhanced set of test. It is more modularized and offers new characteristics, but has some breaking changes.

(TODO)

Support has been implemented for nested object properties.

This will output "Hello jscc":

//#set _OBJ = {p: {p2: {p3: 'Hello jscc'}}}
console.log('$_OBJ.p.p2.p3')

Additionally, the output of undefined values has been optimized. In versions prior to v1, this code:

//#set _OBJ = { foo: 1 }
const foo = $_OBJ.bar

generated:

const foo = {"foo":1}.bar

In v1 the output makes more sense:

const foo = undefined

Unlike previous versions, the output of dates and regexes is the same that of the strings, so you can use them to regenerate the values.

For regexes, the replacement value is taken from the source property and you don't need escape it, but it looses its flags.

For dates, the toJSON() method is used.

Here some examples:

//#set _SBASE = /"[^"]"/.source
//#set _REGEX = RegExp(_SBASE + '|' + _SBASE.replace(/"/g, "'"))
const reForQuotedStrings = /$_REGEX/g

// output:
const reForQuotedStrings = /"[^"]"|'[^']'/g

//#set _DATE = new Date()
export const buildDate = new Date('$_DATE')

// output:
export const buildDate = new Date('2018-10-16T16:51:36.123Z')

The JSON output of those types is consistent with the above:

//#set _OBJ = {regex: _REGEX_, date: _DATE_}
const obj = $_OBJ

// output:
const obj = {"regex":"\"[^\"]\"|'[^']'","date":"2018-10-16T16:51:36.123Z"}

In JS, the output of NaN has different behavior depending if it is wrapped on an object.

Since this is the correct behavior, things are confused when comparing or trying to convert to strings:

jscc v1 changes its behavior on this.

NaN objects or values, alone, are always replaced by NaN.

NaN objects or values as JSON properties are replaced by null.

Infinity is output "as is" if the target is the value alone. In JSON output, Infinity is replaced with Number.MAX_VALUE and -Infinity with Number.MIN_VALUE, because the JSON specs does not allows non-finity numbers.

The result is in the following table: