Allow limiting of recursion in relationships

README.md

@@ -398,7 +398,7 @@ let item1 = this.$store.getters['jv/get']('widget/1')
 
 ```
 
-_Note_ - since relationships can be recursive, calling methods on such objects which try to walk the entire tree will cause recursion errors (e.g. `JSON.stringify`). In order to prevent this common error, a `toJSON` function is added to spot and remove any potentially recursive relationships. In these cases the getter is relpaced with just the `_jv` section, containing `type` and `id` as an indicator of the unfollowed relationship. This behaviour can be disabled - see [toJSON](#Configuration).
+_Note_ - since relationships can be recursive, calling methods on such objects which try to walk the entire tree will cause recursion errors (e.g. `JSON.stringify`). In order to prevent this common error, recursive relationships are replaced with just the `_jv` section, containing `type` and `id` as an indicator of the unfollowed relationship. Recursive relationships can be enabled with the configuration option [recurseRelationships](#Configuration).
 
 ## Helper Functions
 
@@ -487,7 +487,7 @@ For many of these options, more information is provided in the [Usage](#usage) s
 - `clearOnUpdate` - Whether the store should clear old records and only keep new records when updating. Applies to the `type(s)` associated with the new records. (defaults to false).
 - `cleanPatch` - If enabled, patch object is compared to the record in the store, and only unique or modified attributes are kept in the patch. (defaults to false).
 - `cleanPatchProps` - If cleanPatch is enabled, an array of `_jv` properties that should be preserved - `links`, `meta`, and/or `relationships`. (defaults to `[]`).
-- `toJSON` - Add a `toJSON` function to records to remove potentially recursive relationships when serialising to JSON. (defaults to true).
+- `recurseRelationships` - If `false`, replaces recursive relationships with a normalised resource identifier (i.e `{ _jv: { type: 'x', id: 'y' } }`). (defaults to `false`).
 
 ## Endpoints
 

package.json

@@ -82,7 +82,8 @@
     "lodash.clonedeep": "^4.5.0",
     "lodash.get": "^4.4.2",
     "lodash.isequal": "^4.5.0",
-    "lodash.merge": "^4.6.2"
+    "lodash.merge": "^4.6.2",
+    "lodash.set": "^4.3.2"
   },
   "peerDependencies": {
     "vue": "^2.5.17",

src/jsonapi-vuex.js

@@ -1,5 +1,6 @@
 import Vue from 'vue'
 import get from 'lodash.get'
+import set from 'lodash.set'
 import isEqual from 'lodash.isequal'
 import merge from 'lodash.merge'
 import cloneDeep from 'lodash.clonedeep'
@@ -34,8 +35,8 @@ let jvConfig = {
   cleanPatch: false,
   // If cleanPatch is enabled, which _jv props (links, meta, rels) be kept?
   cleanPatchProps: [],
-  // Add a toJSON method to rels to prevent recursion errors
-  toJSON: true,
+  // Allow relationships to be recursive?
+  recurseRelationships: false,
 }
 
 let jvtag
@@ -352,7 +353,7 @@ const actions = (api) => {
 
 const getters = () => {
   return {
-    get: (state, getters) => (data, jsonpath) => {
+    get: (state, getters) => (data, jsonpath, seenState) => {
       let result
       if (!data) {
         // No data arg - return whole state object
@@ -373,7 +374,12 @@ const getters = () => {
             // whole collection, indexed by id
             result = state[type]
           }
-          result = checkAndFollowRelationships(state, getters, result)
+          result = checkAndFollowRelationships(
+            state,
+            getters,
+            result,
+            seenState
+          )
         } else {
           // no records for that type in state
           return {}
@@ -539,16 +545,16 @@ const preserveJSON = (data, json) => {
   return data
 }
 
-const checkAndFollowRelationships = (state, getters, records) => {
+const checkAndFollowRelationships = (state, getters, records, seenState) => {
   if (jvConfig.followRelationshipsData) {
     let resData = {}
     if (jvtag in records) {
       // single item
-      resData = followRelationships(state, getters, records)
+      resData = followRelationships(state, getters, records, seenState)
     } else {
       // multiple items
       for (let [key, item] of Object.entries(records)) {
-        resData[key] = followRelationships(state, getters, item)
+        resData[key] = followRelationships(state, getters, item, seenState)
       }
     }
     if (resData) {
@@ -559,7 +565,7 @@ const checkAndFollowRelationships = (state, getters, records) => {
 }
 
 // Follow relationships and expand them into _jv/rels
-const followRelationships = (state, getters, record) => {
+const followRelationships = (state, getters, record, seenState) => {
   // Copy item before modifying
   const data = cloneDeep(record)
 
@@ -584,41 +590,28 @@ const followRelationships = (state, getters, record) => {
           rootObj = data
           key = relName
         }
-
-        Object.defineProperty(rootObj, key, {
-          get() {
-            return getters.get(`${type}/${id}`)
-          },
-          enumerable: true,
-          // For deletion in `toJSON`
-          configurable: true,
-        })
-
-        if (jvConfig.toJSON) {
-          // Add toJSON method to serialise (potentially recursive) getters
-          if (!rootObj.hasOwnProperty('toJSON')) {
-            Object.defineProperty(rootObj, 'toJSON', {
-              value: function() {
-                const json = Object.assign({}, this)
-                // Store updates may be asynchronous, so test for 'real' data
-                if (this[key].hasOwnProperty(jvtag)) {
-                  const thisjv = this[key][jvtag]
-                  // Replace getter with type and id
-                  json[key] = {
-                    [jvtag]: {
-                      type: thisjv['type'],
-                      id: thisjv['id'],
-                    },
-                  }
-                } else {
-                  // No 'real' data (yet) so delete the getter to prevent recursion
-                  delete json[key]
+        if (type && id) {
+          Object.defineProperty(rootObj, key, {
+            get() {
+              // Return a getter for objects not yet seen...
+              let path = [relName]
+              // Prefix key & id with _ as _.set treats ints are indices, not keys
+              if (relName !== key) {
+                path.push(`_${key}`)
+              }
+              path.push(type, `_${id}`)
+              if (!get(seenState, path)) {
+                if (!jvConfig.recurseRelationships && type && id) {
+                  set(seenState, path, true)
                 }
-                return json
-              },
-              enumerable: false,
-            })
-          }
+                return getters.get(`${type}/${id}`, undefined, seenState)
+              } else {
+                // ... otherwise return a resource identifier object
+                return { [jvtag]: { type: type, id: id } }
+              }
+            },
+            enumerable: true,
+          })
         }
       }
     }

tests/unit/jsonapi-vuex.spec.js

@@ -455,30 +455,38 @@ describe('jsonapi-vuex tests', function() {
           Object.getOwnPropertyDescriptor(rels, 'widgets')
         ).to.have.property('get')
       })
-      it('should add a toJSON method to allow serialisation without recursion', function() {
+
+      it('Should not limit recursion (recurseRelationships)', function() {
+        const { jvConfig } = _testing
+        jvConfig.recurseRelationships = true
         const { followRelationships } = _testing
-        const getters = {
-          get: sinon.stub().returns({ _jv: { type: 'test', id: 1 }, x: 'y' }),
-        }
-        jm = jsonapiModule(api, { followRelationshipsData: true, toJSON: true })
-        let rels = followRelationships(storeRecord, getters, normWidget1)
-        expect(rels).to.have.property('toJSON')
-        // Invoke toJSON
-        const deserial = JSON.parse(JSON.stringify(rels))
-        // _jv preserved, all other attrs dropped
-        expect(deserial['widgets']).to.have.property('_jv')
-        expect(deserial['widgets']).to.not.have.property('x')
-      })
-      it('should add a toJSON method which deletes getters if getter result is empty', function() {
+        let getStub = sinon.stub()
+        const getters = { get: getStub }
+        let rel = followRelationships(storeRecord, getters, normWidget1, {})
+        // 'Get' the getter
+        rel['widgets']
+        // The seenState Object (3rd arg to get()) shouldn't be updated
+        expect(getStub.args[0][2]).to.deep.equal({})
+      })
+
+      it('Should limit recursion (!recurseRelationships)', function() {
+        const { jvConfig } = _testing
+        jvConfig.recurseRelationships = false
         const { followRelationships } = _testing
-        // Return empty object to simulate async action not yet completed
-        const getters = { get: sinon.stub().returns({}) }
-        jm = jsonapiModule(api, { followRelationshipsData: true, toJSON: true })
-        let rels = followRelationships(storeRecord, getters, normWidget1)
-        expect(rels).to.have.property('toJSON')
-        // Invoke toJSON
-        const deserial = JSON.parse(JSON.stringify(rels))
-        expect(deserial).to.not.have.property('widgets')
+        const getters = { get: sinon.stub() }
+
+        // Mark widget/1's rel of widget/2 as already seen
+        let seenState = { widgets: { widget: { _2: true } } }
+        let rels = followRelationships(
+          storeRecord,
+          getters,
+          normWidget1,
+          seenState
+        )
+
+        // The result should be a custom resource identifier
+        // It should *only* have _jv - no attrs or rels as a result
+        expect(rels['widgets']).to.have.all.keys('_jv')
       })
     })
 

yarn.lock

@@ -5854,9 +5854,9 @@ is-resolvable@^1.0.0:
   integrity sha512-qgDYXFSR5WvEfuS5dMj6oTMEbrrSaM0CrFk2Yiq/gXnBvD9pMa2jGXxyhGLfvhZpuMZe18CJpFxAt3CRs42NMg==
 
 is-retry-allowed@^1.0.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/is-retry-allowed/-/is-retry-allowed-1.1.0.tgz#11a060568b67339444033d0125a61a20d564fb34"
-  integrity sha1-EaBgVotnM5REAz0BJaYaINVk+zQ=
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/is-retry-allowed/-/is-retry-allowed-1.2.0.tgz#d778488bd0a4666a3be8a1482b9f2baafedea8b4"
+  integrity sha512-RUbUeKwvm3XG2VYamhJL1xFktgjvPzL0Hq8C+6yrWIswDy3BIXGqCxhxkc30N9jqK311gVU137K8Ei55/zVJRg==
 
 is-stream@^1.0.0, is-stream@^1.1.0:
   version "1.1.0"
@@ -6615,6 +6615,11 @@ lodash.rest@^4.0.0:
   resolved "https://registry.yarnpkg.com/lodash.rest/-/lodash.rest-4.0.5.tgz#954ef75049262038c96d1fc98b28fdaf9f0772aa"
   integrity sha1-lU73UEkmIDjJbR/Jiyj9r58Hcqo=
 
+lodash.set@^4.3.2:
+  version "4.3.2"
+  resolved "https://registry.yarnpkg.com/lodash.set/-/lodash.set-4.3.2.tgz#d8757b1da807dde24816b0d6a84bea1a76230b23"
+  integrity sha1-2HV7HagH3eJIFrDWqEvqGnYjCyM=
+
 lodash.transform@^4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/lodash.transform/-/lodash.transform-4.6.0.tgz#12306422f63324aed8483d3f38332b5f670547a0"
@@ -6967,7 +6972,15 @@ minimist@~0.0.1:
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.10.tgz#de3f98543dbf96082be48ad1a0c7cda836301dcf"
   integrity sha1-3j+YVD2/lggr5IrRoMfNqDYwHc8=
 
-minipass@^2.2.1, minipass@^2.2.4, minipass@^2.3.5:
+minipass@^2.2.1, minipass@^2.2.4:
+  version "2.5.1"
+  resolved "https://registry.yarnpkg.com/minipass/-/minipass-2.5.1.tgz#cf435a9bf9408796ca3a3525a8b851464279c9b8"
+  integrity sha512-dmpSnLJtNQioZFI5HfQ55Ad0DzzsMAb+HfokwRTNXwEQjepbTkl5mtIlSVxGIkOkxlpX7wIn5ET/oAd9fZ/Y/Q==
+  dependencies:
+    safe-buffer "^5.1.2"
+    yallist "^3.0.0"
+
+minipass@^2.3.5:
   version "2.3.5"
   resolved "https://registry.yarnpkg.com/minipass/-/minipass-2.3.5.tgz#cacebe492022497f656b0f0f51e2682a9ed2d848"
   integrity sha512-Gi1W4k059gyRbyVUZQ4mEqLm0YIUiGYfvxhF6SIlk3ui1WVxMTGfGdQ2SInh3PDrRTVvPKgULkpJtT4RH10+VA==