Improved errors thrown when parsing filters

[scottinet]

Description

Errors thrown by Koncorde when it parses filters have useful and descriptive messages for humans, but not so much for developpers trying to handle them efficiently.

This PR brings an overhaul of how Koncorde's filter parser handles errors, with the following improvements:

• errors thrown by Koncorde are now KoncordeParseError errors (extending the plain Error class)
• errors thrown by Koncorde when parsing filters now have a keyword property, explaining what keyword caused the error
• errors thrown by Koncorde when parsing filtrers now have a path property, giving the full path of errors, which is useful when dealing with complex filters with a composition of or and and operands
• errors messages generated when parsing filters now are standardized, they all are like this: "<path>": <message>. That way, users can easily know where their errors are

Example:

const { Koncorde } = require('koncorde');

const k = new Koncorde();

k.validate({ or: [ { and: [ { exists: {} } ] } ] });
/* 
Throws this error:

KoncordeParseError: "or.and.exists": expected object to have exactly 1 property, got 0
    at isObject (/home/scottinet/git/koncorde/lib/transform/standardize.js:787:13)
    at Standardizer.exists (/home/scottinet/git/koncorde/lib/transform/standardize.js:125:5)
    at Standardizer.standardize (/home/scottinet/git/koncorde/lib/transform/standardize.js:92:29)
    at /home/scottinet/git/koncorde/lib/transform/standardize.js:722:22
    at Array.map (<anonymous>)
    at Standardizer._standardizeFilterArray (/home/scottinet/git/koncorde/lib/transform/standardize.js:722:8)
    at Standardizer.and (/home/scottinet/git/koncorde/lib/transform/standardize.js:584:17)
    at Standardizer.standardize (/home/scottinet/git/koncorde/lib/transform/standardize.js:92:29) {
  keyword: 'exists',
  path: 'or.and.exists'
*/

[codecov]

Codecov Report

Merging #49 (7df12bf) into 4-dev (33f35a4) will decrease coverage by 0.13%.
The diff coverage is 99.30%.

@@            Coverage Diff             @@
##            4-dev      #49      +/-   ##
==========================================
- Coverage   96.89%   96.76%   -0.14%     
==========================================
  Files          33       34       +1     
  Lines         967      958       -9     
  Branches       32       33       +1     
==========================================
- Hits          937      927      -10     
- Misses         29       30       +1     
  Partials        1        1              

Impacted Files	Coverage Δ
lib/index.ts	97.33% <ø> (ø)
lib/transform/standardize.js	97.48% <99.27%> (-0.55%)	⬇️
lib/types/KoncordeParseError.ts	100.00% <100.00%> (ø)
lib/util/hash.js	100.00% <0.00%> (ø)

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[lgtm-com]

This pull request fixes 2 alerts when merging ad30a17 into 6ea7509 - view on LGTM.com

fixed alerts:

• 1 for Polynomial regular expression used on uncontrolled data
• 1 for Useless assignment to property