Implement name disambiguation

Signed-off-by: RMidhunSuresh <rmidhunsuresh@gmail.com>

src/domain/session/rightpanel/disambiguator.js

@@ -0,0 +1,147 @@
+export class Disambiguator {
+    constructor() {
+        this._map = new Map();
+    }
+
+    _flatten(name, array) {
+        const vm = array.pop();
+        vm.setDisambiguation(false);
+        this._map.set(name, vm);
+    }
+
+    _unDisambiguate(vm, array) {
+        const idx = array.indexOf(vm);
+        if (idx !== -1) {
+            const [removed] = array.splice(idx, 1);
+            removed.setDisambiguation(false);
+        }
+    }
+
+    async _handlePreviousName(vm) {
+        const previousName = vm.previousName;
+        if (!previousName) { return; }
+        const value = this._map.get(previousName);
+        if (Array.isArray(value)) {
+            this._unDisambiguate(vm, value);
+            if (value.length === 1) { this._flatten(previousName, value); }
+        } else {
+            this._map.delete(previousName);
+        }
+    }
+
+    async _updateMap(vm) {
+        const name = vm.name;
+        if (this._map.has(name)) {
+            const value = this._map.get(name);
+            if (Array.isArray(value)) {
+                value.push(vm);
+            } else {
+                this._map.set(name, [value, vm]);
+            }
+        } else {
+            this._map.set(name, vm);
+        }
+    }
+
+    async disambiguate(vm) {
+        if (!vm.nameChanged) { return; }
+        await this._handlePreviousName(vm);
+        await this._updateMap(vm);
+        const value = this._map.get(vm.name);
+        if (Array.isArray(value)) {
+            value.forEach((vm) => vm.setDisambiguation(true));
+        }
+    }
+}
+
+export function tests(){
+
+    class MockViewModel {
+        constructor(name, userId) {
+            this.name = name;
+            this.disambiguate = false;
+            this.userId = userId;
+            this.nameChanged = true;
+        }
+        
+        updateName(newName) {
+            if (this.name !== newName) {
+                this.previousName = this.name;
+                this.nameChanged = true;
+            }
+            else {
+                this.nameChanged = false;
+            }
+            this.name = newName;
+        }
+
+        setDisambiguation(status) {
+            this.disambiguate = status;
+        }
+    }
+
+    function createVmAndDisambiguator(nameList) {
+        const d = new Disambiguator();
+        const array = nameList.map(([name, id]) => new MockViewModel(name, id));
+        return [...array, d];
+    }
+
+    return {
+        "Unique names": async assert => {
+            const [vm1, vm2, d] = createVmAndDisambiguator([["foo", "a"], ["bar", "b"]]);
+            await d.disambiguate(vm1);
+            await d.disambiguate(vm2);
+            assert.strictEqual(vm1.disambiguate, false);
+            assert.strictEqual(vm2.disambiguate, false);
+        },
+
+        "Same names are disambiguated": async assert => {
+            const [vm1, vm2, vm3, d] = createVmAndDisambiguator([["foo", "a"], ["foo", "b"], ["foo", "c"]]);
+            await d.disambiguate(vm1);
+            await d.disambiguate(vm2);
+            await d.disambiguate(vm3);
+            assert.strictEqual(vm1.disambiguate, true);
+            assert.strictEqual(vm2.disambiguate, true);
+            assert.strictEqual(vm3.disambiguate, true);
+        },
+
+        "Name updates disambiguate": async assert => {
+            const [vm1, vm2, vm3, d] = createVmAndDisambiguator([["foo", "a"], ["bar", "b"], ["jar", "c"]]);
+            await d.disambiguate(vm1);
+            await d.disambiguate(vm2);
+            await d.disambiguate(vm3);
+            
+            vm2.updateName("foo");
+            await d.disambiguate(vm2);
+            assert.strictEqual(vm1.disambiguate, true);
+            assert.strictEqual(vm2.disambiguate, true);
+
+            vm1.updateName("bar");
+            await d.disambiguate(vm1);
+            assert.strictEqual(vm1.disambiguate, false);
+            assert.strictEqual(vm2.disambiguate, false);
+
+            vm3.updateName("foo");
+            await d.disambiguate(vm3);
+            vm1.updateName("foo");
+            await d.disambiguate(vm1);
+            assert.strictEqual(vm1.disambiguate, true);
+            assert.strictEqual(vm2.disambiguate, true);
+            assert.strictEqual(vm3.disambiguate, true);
+
+            vm2.updateName("bar");
+            await d.disambiguate(vm2);
+            assert.strictEqual(vm1.disambiguate, true);
+            assert.strictEqual(vm2.disambiguate, false);
+            assert.strictEqual(vm3.disambiguate, true);
+        },
+
+        "Multiple disambiguate events": async assert => {
+            const [vm1, d] = createVmAndDisambiguator([["foo", "a"]]);
+            await d.disambiguate(vm1);
+            vm1.updateName(vm1.name);
+            await d.disambiguate(vm1);
+            assert.strictEqual(vm1.disambiguate, false);
+        },
+    };
+}