Make LineUp v4 RegExp filter serialization backwards compatible

[oltionchampari]

Close #331

Summary

• Extended tests for serializeLineUpFilter() and restoreRegExp() functions.
• Refactored the functions to be backwards compatible.

[thinkh]

I made some changes to the file structure and added an unknown error. I'm still unsure about the typeguard function. Please have a look again. Thanks.

[thinkh]

Suggested change

	export function isSerializedFilter(filter: any): ISerializableLineUpFilter {
	export function isSerializedFilter(filter: any): filter is ISerializableLineUpFilter {

I would expect that this is a type guard function. And the return statement indicates a boolean return value. Please revise.

[oltionchampari]

The function checks if the filter is ISerializableLineUpFilter | ILineUpStringFilter, so i added a typeguard that includes both.

[thinkh]

That fix was only part of the solution. The reason why you had to add ILineUpStringFilter to everything was that we were using the function isSerializedFilter in recordPropertyChange which is incorrect! Instead we must check if the provided filter is a valid ILineUpStringFilter. I refactored the code and extracted + tested the type guards.

[thinkh]

I added this error message to prevent cases where the return value of this function is void. After playing around with this implementation I got an error with the regexp string:

This is the error in the console:

filter.ts:125 Uncaught (in promise) Error: Unknown LineUp filter format. Unable to restore the given filter.
    at restoreLineUpFilter (filter.ts:125)
    at restoreLineUpFilter (filter.ts:121)
    at ActionNode.<anonymous> (cmds.ts:227)
    at Generator.next (<anonymous>)
    at fulfilled (tslib.es6.js:71)

@oltionchampari Can you check why calling it recursively (starting from line 121) and not returning void (without the error) and now we run into the error? In guess is that we still have an uncovered case where the three typeguards above are not working correctly.

My expectation would be that we do not get the error message and one of the typeguards catches the recursive call and returns a valid filter object.

[oltionchampari]

The issue was that when you go back in the provenance graph the restoreLineUpFilter()
function gets called with the old value which gets derived from the Ranking.Thus it hasn't been serialized:

const fromGraphFilter = {filter: /abc/, filterMissing: false};
  restoreLineUpFilter(fromGraphFilter)

I added a test to cover this case and returned the filter when it's already serialized.

[thinkh]

@oltionchampari I refactored the code again and wrote more type guards and tests. For me it works, but can you please check and test the solution in the browser again. If you do not find any errors or flaws we are ready to merge.

[oltionchampari]

It works as expected for me too, i see no problems with it. The code is much better organized now.