docs: descriptions of current problems for ng-team

Author: vakrilov

build-for-ivy.md

@@ -41,4 +41,50 @@ resolve: {
 
 - Currently the ./bin scripts are not packed in the npm package
 - Zone.js distribution is modified to be TS compilable
-- There are no secondary (ex. `nativescript-angular/router`) entry points for `nativescript-angular`, which is a breaking change
+- There are no secondary (ex. `nativescript-angular/router`) entry points for `nativescript-angular`, which is a breaking change
+
+
+## Questions for Angular Team
+
+### 1. CommonJS Support 
+No support for commonJS currently. The `nativescript-angular` package is not picked up by the compatibility compiler (`ivy-ngcc`)
+
+**Note:** We noticed that `ngcc` reads the entry-point based on `package.json` files. In the `nativescript-angular`package there are many files that can be imported directly ex. `nativescript-angular/router` or `nativescript-angular/modal-dialog` which are not separate modules and don't have a dedicated `package.json` file describing them. Is there a way to make sure **all** files in an npm package are traversed by `ngcc` when it starts to support commonjs?
+
+### 2. Platform-specific Files in NGCC Resolver 
+We tried to pack `nativescript-angular` with `ng-packger`. However, our main entry point gets ignored by the `ngcc`. The reason - it includes `tns-core-modules\application` which is plat-specific file (has `application.andorid.js` and `application.ios.js`). The `ngcc` could not resolve the import and decides to skip tha package. We patched it by commenting this line (just for the sake of spike): https://github.com/angular/angular/blob/41737bb4d3489bbfe1d2631cc1a7e9f4a732b8ff/packages/compiler-cli/ngcc/src/packages/dependency_resolver.ts#L117.
+We probably need to be able to pass in custom resolver that can understand `.[android/ios].js` extension as this is a common way for defining platform-specific files in NativeScript.
+
+
+### 3. Generated Compat Code Imports 
+Running `ivy-ngcc` adds two imports at the start of the file:
+
+```
+import * as ɵngcc0 from '@angular/core';
+import * as ɵngcc1 from '@angular/common';
+
+import 'tns-core-modules/globals';
+```
+However, importing `@angular/core` before `tns-core-modules/globals` (the first import in the file) causes the following runtime crash: `ReferenceError: Can't find variable: setTimeout`. This is because `setTimeout` is defined in the global scope by `tns-core-modules/globals`. We traced the usage of `setTimeout` to here: https://github.com/angular/angular/blob/41737bb4d3489bbfe1d2631cc1a7e9f4a732b8ff/packages/core/src/render3/util/misc_utils.ts#L39-L42 
+We have couple of suggestions to resolve this:
+
+    1. Add the generated `ɵngcc0` imports after all other imports in the file. This will assure that side-effects introduced by imports are handled the same way before and after the file is converted by the `ngcc`.
+    2. Have the `defaultScheduler` initialized when first needed or injected by the platform.
+
+
+### 4. Generated Compat Function With Duplicating Name 
+`ivy-ngcc` generate the following code just after import statements:
+```
+const _c0 = ["loader", ""];
+const _c1 = [];
+const _c2 = [4, "ngIf"];
+function _0_Template(rf, ctx) { if (rf & 1) {
+    ɵngcc0.ɵprojection(0, 0, ["*ngIf", "show"]);
+} }
+function _0_Template(rf, ctx) { if (rf & 1) {
+    ɵngcc0.ɵprojection(0, 0, ["*ngIf", "show"]);
+} }
+const _c3 = ["isEmptyOutlet", "true"];
+```
+
+The function `_0_Template` is duplicated. This happens when compiling the templates for this file: https://github.com/NativeScript/nativescript-angular/blob/master/nativescript-angular/directives/platform-filters.ts . We tried splitting the file into two separate component and changing the templates to be different, but the generated code remains the same. Seems like a bug in the `ngcc`

nativescript-angular/package.json

@@ -45,37 +45,37 @@
     "reflect-metadata": "^0.1.8"
   },
   "peerDependencies": {
-    "@angular/platform-browser-dynamic": "~8.0.0-beta.7",
-    "@angular/common": "~8.0.0-beta.7",
-    "@angular/compiler": "~8.0.0-beta.7",
-    "@angular/core": "~8.0.0-beta.7",
-    "@angular/forms": "~8.0.0-beta.7",
-    "@angular/http": "~8.0.0-beta.7",
-    "@angular/platform-browser": "~8.0.0-beta.7",
-    "@angular/router": "~8.0.0-beta.7",
+    "@angular/platform-browser-dynamic": "8.0.0-beta.8",
+    "@angular/common": "8.0.0-beta.9",
+    "@angular/compiler": "8.0.0-beta.9",
+    "@angular/core": "8.0.0-beta.9",
+    "@angular/forms": "8.0.0-beta.9",
+    "@angular/http": "8.0.0-beta.9",
+    "@angular/platform-browser": "8.0.0-beta.9",
+    "@angular/router": "8.0.0-beta.9",
     "rxjs": "^6.3.3",
     "tns-core-modules": "^5.1.0 || >5.1.0- || >5.2.0-",
     "typescript": "~3.1.1",
     "zone.js": "^0.8.4"
   },
   "devDependencies": {
-    "@angular/animations": "~8.0.0-beta.7",
-    "@angular/common": "~8.0.0-beta.7",
-    "@angular/compiler": "~8.0.0-beta.7",
-    "@angular/compiler-cli": "~8.0.0-beta.7",
-    "@angular/core": "~8.0.0-beta.7",
-    "@angular/forms": "~8.0.0-beta.7",
-    "@angular/http": "~8.0.0-beta.7",
-    "@angular/platform-browser": "~8.0.0-beta.7",
-    "@angular/platform-browser-dynamic": "~8.0.0-beta.7",
-    "@angular/router": "~8.0.0-beta.7",
+    "@angular/animations": "8.0.0-beta.9",
+    "@angular/common": "8.0.0-beta.9",
+    "@angular/compiler": "8.0.0-beta.9",
+    "@angular/compiler-cli": "8.0.0-beta.9",
+    "@angular/core": "8.0.0-beta.9",
+    "@angular/forms": "8.0.0-beta.9",
+    "@angular/http": "8.0.0-beta.9",
+    "@angular/platform-browser": "8.0.0-beta.9",
+    "@angular/platform-browser-dynamic": "8.0.0-beta.9",
+    "@angular/router": "8.0.0-beta.9",
     "codelyzer": "^4.5.0",
     "ng-packagr": "^4.7.1",
     "rxjs": "~6.3.3",
     "tns-core-modules": "next",
     "tsickle": "^0.34.3",
     "tslint": "^5.5.0",
-    "typescript": "~3.1.1",
+    "typescript": "~3.3.4000",
     "zone.js": "^0.8.4"
   }
 }