"Attempted to assign to readonly property" in 5 of my unit tests since I upgraded Angular from 2.1.0 to 2.4.3

[Sebastien ARBOGAST]

Hello everyone,

Since I upgraded AngularJS on my project from 2.1.0 to 2.4.3, 5 of my 86 unit tests give me the following error:

TypeError: Attempted to assign to readonly property. in src/test.ts (line 12465)

        set@webpack:///~/@angular/core/src/facade/errors.js:43:33 <- src/test.ts:12465:52

        assignAll@webpack:///~/zone.js/dist/zone.js:704:0 <- src/test.ts:135599:23

        ZoneAwareError@webpack:///~/zone.js/dist/zone.js:775:0 <- src/test.ts:135670:25

        BaseError@webpack:///~/@angular/core/src/facade/errors.js:26:0 <- src/test.ts:12448:20

        WrappedError@webpack:///~/@angular/core/src/facade/errors.js:88:0 <- src/test.ts:12510:20

        ViewWrappedError@webpack:///~/@angular/core/src/linker/errors.js:73:0 <- src/test.ts:70362:20

        _rethrowWithContext@webpack:///~/@angular/core/src/linker/view.js:650:0 <- src/test.ts:108480:92

        detectChanges@webpack:///~/@angular/core/src/linker/view.js:623:0 <- src/test.ts:108453:37

        detectChanges@webpack:///~/@angular/core/src/linker/view_ref.js:179:0 <- src/test.ts:71308:33

        _tick@webpack:///~/@angular/core/bundles/core-testing.umd.js:191:0 <- src/test.ts:8995:49

        webpack:///~/@angular/core/bundles/core-testing.umd.js:205:45 <- src/test.ts:9009:58

        invoke@webpack:///~/zone.js/dist/zone.js:242:0 <- src/test.ts:135137:31

        onInvoke@webpack:///~/zone.js/dist/proxy.js:79:0 <- src/test.ts:95512:45

        invoke@webpack:///~/zone.js/dist/zone.js:241:0 <- src/test.ts:135136:40

        onInvoke@webpack:///~/@angular/core/src/zone/ng_zone.js:269:0 <- src/test.ts:38860:43

        invoke@webpack:///~/zone.js/dist/zone.js:241:0 <- src/test.ts:135136:40

        run@webpack:///~/zone.js/dist/zone.js:113:0 <- src/test.ts:135008:49

        run@webpack:///~/@angular/core/src/zone/ng_zone.js:138:42 <- src/test.ts:38729:65

        detectChanges@webpack:///~/@angular/core/bundles/core-testing.umd.js:205:0 <- src/test.ts:9009:32

        webpack:///src/app/login/login.component.spec.ts:42:25 <- src/test.ts:113623:30

        invoke@webpack:///~/zone.js/dist/zone.js:242:0 <- src/test.ts:135137:31

        onInvoke@webpack:///~/zone.js/dist/proxy.js:79:0 <- src/test.ts:95512:45

        invoke@webpack:///~/zone.js/dist/zone.js:241:0 <- src/test.ts:135136:40

        run@webpack:///~/zone.js/dist/zone.js:113:0 <- src/test.ts:135008:49

        webpack:///~/zone.js/dist/jasmine-patch.js:102:0 <- src/test.ts:95227:37

        execute@webpack:///~/zone.js/dist/jasmine-patch.js:132:0 <- src/test.ts:95257:46

        execute@webpack:///~/zone.js/dist/jasmine-patch.js:132:0 <- src/test.ts:95257:46

        invokeTask@webpack:///~/zone.js/dist/zone.js:275:0 <- src/test.ts:135170:40

        runTask@webpack:///~/zone.js/dist/zone.js:151:0 <- src/test.ts:135046:57

        drainMicroTaskQueue@webpack:///~/zone.js/dist/zone.js:433:0 <- src/test.ts:135328:42

        invoke@webpack:///~/zone.js/dist/zone.js:349:0 <- src/test.ts:135244:44

        webpack:///~/zone.js/dist/zone.js:1298:0 <- src/test.ts:136193:30

How can I troubleshoot that kind of problem?

Best,

Sébastien