Feature/update json rules engine (#101)

* Simplified rules unit tests

* Updated json-rules-engine

* Updated code to use native json-rules-engine jsonpath syntax

* Made linter happy. Removed jsonpath dependency.

package.json

@@ -59,8 +59,7 @@
     "good-console": "8.0.0",
     "good-squeeze": "5.1.0",
     "hapi-openapi": "1.2.6",
-    "json-rules-engine": "4.1.0",
-    "jsonpath": "1.0.2",
+    "json-rules-engine": "5.0.0",
     "knex": "0.20.3",
     "memory-cache": "0.2.0",
     "mysql": "2.17.1",

src/model/rules.js

@@ -37,7 +37,6 @@
  */
 
 const jre = require('json-rules-engine')
-const jsonpath = require('jsonpath')
 const assert = require('assert').strict
 
 module.exports.events = {
@@ -67,97 +66,6 @@ const createEngine = () => {
     return deepEqual(factValue, ruleValue)
   })
 
-  /**
-   * The json-rules-engine path only supports selectn paths. This is problematic, as selectn cannot
-   * traverse an array with filters, it can only use a static array index. For example, selectn
-   * cannot find the age of user with name 'Tutaia' in the following array, without knowing in
-   * advance that Tutaia will be the first element of the array:
-   *
-   *   [ { name: 'Tutaia', age: 25 }, { name: 'Kim', age: 66 } ]
-   *
-   * In many (most) cases we cannot know the order and content of our data in advance. We therefore
-   * provide a more flexible, but still declarative jsonpath dynamic fact. Note that the examples
-   * provided below in this comment are reproduced in the tests.
-   *
-   * Note that the jsonPathFact requires the deepEqual operator to function correctly, as jsonpath
-   * returns an array of results.
-   *
-   * See https://www.npmjs.com/package/jsonpath for more information on jsonpath.
-   *
-   * The json-path fact exploits the fact params as its API by allowing the user to specify the fact
-   * they'd like to retrieve and a jsonpath within that fact.
-   *
-   * The following example looks at the payload fact, and checks whether the payer fspId, at jsonpath
-   * `$.payload.payer.partyIdInfo.fspId` is not `payerfsp`:
-   *
-   *   {
-   *     fact: 'json-path',
-   *     params: {
-   *       fact: 'payload',
-   *       path: '$.payload.payer.partyIdInfo.fspId'
-   *     },
-   *     operator: 'notDeepEqual',
-   *     value: [ 'payerfsp' ]
-   *   }
-   *
-   * Note that the value of .params.fact will be a top-level key in the jsonpath query, and therefore
-   * must correspond to the top-level key in .params.path. A general example:
-   *
-   *   {
-   *     fact: 'json-path',
-   *     params: {
-   *       fact: 'top-level-key',
-   *       path: '$.top-level-key'
-   *     },
-   *     ...
-   *   }
-   *
-   * Supported top-level keys (facts) are:
-   * - payload
-   * - headers
-   * - payer
-   * - payee
-   *
-   * Another slightly more complex example, comparing the value of the fspiop-source header with the
-   * payer fspId in the payload:
-   *
-   *   {
-   *     fact: 'json-path',
-   *     params: {
-   *       fact: 'payload',
-   *       path: '$.payload.payer.partyIdInfo.fspId'
-   *     },
-   *     operator: 'deepEqual',
-   *     value: {
-   *       fact: 'json-path',
-   *       params: {
-   *         path: '$.headers[\'fspiop-source\']',
-   *         fact: 'headers'
-   *       }
-   *     }
-   *   }
-   *
-   * So far, no example rules have _required_ the use of jsonpath. The following rule filters the
-   * KYCPayerTier key in the extension list of the quote payload and verifies that it is '1':
-   *
-   *   {
-   *     fact: 'json-path',
-   *     params: {
-   *       fact: 'payload',
-   *       path: '$.payload.extensionList[?(@.key === \'KYCPayerTier\')].value'
-   *     },
-   *     operator: 'deepEqual',
-   *     value: [ '1' ]
-   *   }
-   */
-  const jsonPathFact = function (params, almanac) {
-    return almanac.factValue(params.fact)
-      .then((fact) => {
-        return jsonpath.query({ [params.fact]: fact }, params.path)
-      })
-  }
-  engine.addFact('json-path', jsonPathFact)
-
   return engine
 }