FLUID-5517 test case demonstrating FLOE-230 failure

gistfile1.txt

    // FLUID-5517: Failure to batch compound updates properly - example from metadata feedback
    
    fluid.defaults("fluid.tests.fluid5517root", {
        gradeNames: ["fluid.standardRelayComponent", "autoInit"],
        model: {
            userData: {
                opinion: {
                    mismatch: true
                }
            },
            inTransit: {
                opinion: ["dislike"]   // Possible values: like, dislike
            }
        },
        modelRelay: [{
            source: "{that}.model.inTransit.opinion",
            target: "{that}.model.userData.opinion",
            forward: "liveOnly",
            singleTransform: {
                type: "fluid.transforms.arrayToSetMembership",
                options: {
                    "like": "match",
                    "dislike": "mismatch"
                }
            }
        }],
        events: {
            onFeedbackMarkupReady: null
        },
        components: {
            bindMatchConfirmation: {
                type: "fluid.standardRelayComponent",
                createOnEvent: "onFeedbackMarkupReady",
                options: {
                    modelRelay: {
                        source: "{fluid5517root}.model.inTransit",
                        target: "{that}.model.isActive",
                        backward: "liveOnly",
                        transform: {
                            transform: {
                                type: "fluid.transforms.arrayToSetMembership",
                                inputPath: "opinion",
                                options: {
                                    "like": ""
                                }
                            }
                        }
                    }
                }
            },
            bindMismatchDetails: {
                type: "fluid.standardRelayComponent",
                createOnEvent: "onFeedbackMarkupReady",
                options: {
                    modelRelay: {
                        source: "{fluid5517root}.model.inTransit",
                        target: "{that}.model.isActive",
                        backward: "liveOnly",
                        transform: {
                            transform: {
                                type: "fluid.transforms.arrayToSetMembership",
                                inputPath: "opinion",
                                options: {
                                    "dislike": ""
                                }
                            }
                        }
                    }
                }
            }
        }
    });
    
    fluid.tests.dumpModel = function (that) {
        console.log("Root model: ", JSON.stringify(that.model, null, 2));
        if (that.bindMatchConfirmation) {
            console.log("Match model: ", JSON.stringify(that.bindMatchConfirmation.model, null, 2));
            console.log("Mismatch model: ", JSON.stringify(that.bindMismatchDetails.model, null, 2));
        }
    };
    jqUnit.test("FLUID-5517: Batching failure in model relay", function () {
        var that = fluid.tests.fluid5517root();
        jqUnit.assertDeepEq("Initial model synchronised", ["dislike"], that.model.inTransit.opinion);
        fluid.tests.dumpModel(that);
        console.log("=============================== FIRING ATTACHMENT EVENT ================");
        that.events.onFeedbackMarkupReady.fire();
        fluid.tests.dumpModel(that);

        that.applier.change("userData.opinion.match", true);
        jqUnit.assertDeepEq("Stabilised model synchronised", ["like"], that.model.inTransit.opinion);
        
        fluid.tests.dumpModel(that);
    });
    
    
    
OUTPUT AFTER firing change from line 89: 
    
Root model:

{
  "userData": {
    "opinion": {
      "mismatch": true,
      "match": false
    }
  },
  "inTransit": {
    "opinion": [
      "dislike"
    ]
  }
}
Match model:
{
  "isActive": false
}
Mismatch model:
{
  "isActive": true
}

setMembershipToArray making output ["like","dislike"] given options {"match":"like","mismatch":"dislike"}
arrayToSetMembership with options {"like":"match","dislike":"mismatch"} and input value ["like","dislike"]
arrayToSetMembership setting path match to true
arrayToSetMembership setting path mismatch to true
arrayToSetMembership with options {"like":""} and input value ["like","dislike"]
arrayToSetMembership setting path  to true
setMembershipToArray making output ["like"] given options {"":"like"}  <------ PROBLEM HERE! target array has been overwritten with this incomplete relay result

Note - the "proper" solution to this problem (or rather, the only one we can implement without stateful relay rules) is simple-seeming but rather obscure - it was explained in IRC at https://botbot.me/freenode/fluid-work/2014-08-25/?msg=20363141&page=2

The idea is to tackle the issue at the point of initial data binding - the UI action of selecting, say, the "match" button is not bound to the boolean end of the relay, but the array and - and the binding has the effect, say, of writing the entire array ["match"] to the so-called "inTransit.opinion" (this needs to be renamed) - rather than writing to the boolean end of the relay.