# NG Update - post update message as part update experience

## Goal
Display a message in the console after the executions of migration scripts.

## Option 1
* Add a new migration with a highest number so that it runs at the very end.
* Example if the current greater version of the migrations is set `9.0.0-beta` this should be set to `9.0.0-rc`
* Add the message in the schematic factory code.
* Mark it as hidden so that we don't print the description in the console. (Need to add this minimal logic in the CLI)

### Some important notes
Prior to cutting the final v9 release we should ensure that all migrations are re-run including the message migration when users update from a RC version.

To ensure this and that the message is printed at the end we need to update all migrations version to a non existing versions such as `9.0.0-rc.999` and the message migration to `9.0.0`.

Even then this message will be printed at the version end of the `@angular/core` migrations. Meaning that if a user choose to update multiple packages at once, Example using:

ng update @angular/cli @angular/core @nguniversal-express-engine

The Angular 9 message will be printed at the end of `@angular/core` migrations but before the `@nguniversal-express-engine` migrations messages.

## Option 2 (Ditched)

### Proposed schema updates

Add a section in the migration collection to include post execution options.

This will be an Array of Object Literals will include 2 properties:
1. `message`: The text to printed in the console.
2. `schematicNames`: An Array of schematics names to print the `message` for. When one or more of the listed schematics are executed the `message` will be printed once in console.

{
  "schematics": {
    "migration-v8-move-document": {
      "version": "8.0.0-beta",
      "description": "...",
      "factory": "./migrations/move-document/index"
    },
    "migration-v9-postinstall-ngcc": {
      "version": "9-beta",
      "description": "...",
      "factory": "./migrations/postinstall-ngcc/index"
    },
    "migration-v9-module-with-providers": {
      "version": "9.0.0-beta",
      "description": "...",
      "factory": "./migrations/module-with-providers/index"
    }
  },
  "postExecutions": [
    {
      "schematicNames": [
        "migration-v8-move-document"
      ],
      "message": "Angular version 8 has several new shinny features. See more info here: https://v8.angular.io"
    },
    {
      "schematicNames": [
        "migration-v9-module-with-providers",
        "migration-v9-postinstall-ngcc"
      ],
      "message": "Angular version 9 has several new shinny features. See more info here: https://v9.angular.io"
    }
  ]
}