fix(resolve): Don't re-resolve data when redirected to same state, but only dynamic params changed.

Closes #3033

Author: christopherthielen

src/path/node.ts

@@ -79,15 +79,23 @@ export class PathNode {
    *
    * The new path starts from root and contains any nodes that match the nodes in the second path.
    * Nodes are compared using their state property and parameter values.
+   *
+   * @param pathA the first path
+   * @param pathB the second path
+   * @param ignoreDynamicParams don't compare dynamic parameter values
    */
-  static matching(pathA: PathNode[], pathB: PathNode[]): PathNode[] {
+  static matching(pathA: PathNode[], pathB: PathNode[], ignoreDynamicParams = true): PathNode[] {
     let matching: PathNode[] = [];
 
     for (let i = 0; i < pathA.length && i < pathB.length; i++) {
       let a = pathA[i], b = pathB[i];
 
       if (a.state !== b.state) break;
-      if (!Param.equals(a.paramSchema, a.paramValues, b.paramValues)) break;
+
+      let changedParams = Param.changed(a.paramSchema, a.paramValues, b.paramValues)
+          .filter(param => !(ignoreDynamicParams && param.dynamic));
+      if (changedParams.length) break;
+
       matching.push(a);
     }
 

test/core/resolveSpec.ts

@@ -3,7 +3,7 @@
 import "../matchers.ts"
 
 import { ResolveContext, State, PathNode, Resolvable } from "../../src/core";
-import { omit, pick, forEach, copy } from "../../src/core";
+import { copy } from "../../src/core";
 
 import Spy = jasmine.Spy;
 import {services} from "../../src/common/coreservices";
@@ -365,6 +365,39 @@ describe('Resolvables system:', function () {
       done();
     });
   });
+
+  // Test for #2796
+  it("should not re-resolve data, when redirecting to self with dynamic parameter update", (done) => {
+    let $registry = router.stateRegistry;
+    let $state = router.stateService;
+    let $transitions = router.transitionService;
+    let resolveCount = 0;
+
+    $registry.register({
+      name: 'dynamic',
+      url: '/dynamic/{param}',
+      params: {
+        param: { dynamic: true }
+      },
+      resolve: {
+        data: () => {
+          new Promise(resolve => resolve('Expensive data ' + resolveCount++))
+        }
+      }
+    });
+
+    $transitions.onEnter({entering: "dynamic"}, trans => {
+      if (trans.params()['param'] === 'initial')
+        return $state.target("dynamic", { param: 'redirected' });
+    });
+
+    $state.go("dynamic", { param: 'initial'}).then(() => {
+      expect($state.current.name).toBe("dynamic");
+      expect($state.params['param']).toBe('redirected');
+      expect(resolveCount).toBe(1);
+      done();
+    });
+  });
 });