refactor: move notification types to common package

Currently, the notification types in `protocol.ts` are duplicated in both
`client` and `server`.

This commit consolidates them into `common` and create a project reference.
This is done in preparation for the ngcc work, which will add more notification
types.

With this change, `client` and `server` now have to depend on the `.d.ts`
output of `common`.
Although this is the right way to organize the code, it introduces two
unfortunate side effects:

1. `client` and `server` now have to import from `common/out`, since that's
   the output directory where the declaration files are emitted.
2. users who clone this repo will have to run `yarn compile` to build the
   repo before they can navigate the project in their editor.

(1) does not look "nice", but it offers a straight-forward way without too
drastic changes to the build workflow.

While (2) this is not ideal, it is the correct way of using project references
according to the TS [documentation](https://www.typescriptlang.org/docs/handbook/project-references.html#caveats-for-project-references).

> Because dependent projects make use of .d.ts files that are built from their
> dependencies, you’ll either have to check in certain build outputs or build
> a project after cloning it before you can navigate the project in an editor
> without seeing spurious errors.

TypeScript does plan to improve the ergonomics of project references in the
future.

> We’re working on a behind-the-scenes .d.ts generation process that should be
> able to mitigate this, but for now we recommend informing developers that
> they should build after cloning.

Author: kyliau

.gitignore

@@ -4,6 +4,7 @@
 node_modules
 client/node_modules/
 client/out/
+common/out
 server/node_modules/
 server/out
 integration/out

DEVELOPER.md

@@ -1,3 +1,20 @@
+## Navigating Projects in IDE
+
+This repository contains multiple TypeScript projects, each with its own `tsconfig.json`.
+TypeScript's [project references](https://www.typescriptlang.org/docs/handbook/project-references.html) are used to handle the builds.
+As a result, some projects depend on the `.d.ts` output of their dependencies, like `client`
+and `server` depend on `common`. In order to navigate the projects in your IDE,
+you need to first build them by running
+```shell
+yarn compile
+```
+
+If you'd like to force a clean build, you can delete the existing build artifacts
+by running
+```shell
+./scripts/build.sh
+```
+
 ## Formatting source code
 
 This repository uses the [NPM distribution](https://www.npmjs.com/package/clang-format) of

client/src/extension.ts

@@ -11,8 +11,9 @@ import * as path from 'path';
 import * as vscode from 'vscode';
 import * as lsp from 'vscode-languageclient';
 
+import {projectLoadingNotification} from '../../common/out/notifications';
+
 import {registerCommands} from './commands';
-import {projectLoadingNotification} from './protocol';
 
 export function activate(context: vscode.ExtensionContext) {
   // If the extension is launched in debug mode then the debug server options are used

client/src/protocol.ts

@@ -3,6 +3,9 @@
   "compilerOptions": {
     "outDir": "out"
   },
+  "references": [
+    {"path": "../common"}
+  ],
   "include": ["src"],
   "exclude": ["node_modules"]
 }

client/tsconfig.json

@@ -6,9 +6,9 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {NotificationType0} from 'vscode-languageserver';
+import {NotificationType0} from 'vscode-jsonrpc';
 
 export const projectLoadingNotification = {
-  start: new NotificationType0<string>('angular-language-service/projectLoadingStart'),
-  finish: new NotificationType0<string>('angular-language-service/projectLoadingFinish')
+  start: new NotificationType0('angular/projectLoadingStart'),
+  finish: new NotificationType0('angular/projectLoadingFinish')
 };

server/src/protocol.ts renamed to common/notifications.ts

@@ -0,0 +1,9 @@
+{
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "composite": true,
+    "outDir": "out",
+    "rootDir": ".",
+  },
+  "include": ["*.ts"]
+}

common/tsconfig.json

@@ -6,6 +6,7 @@ set -ex -o pipefail
 shopt -s extglob
 
 # Clean up from last build
+rm -rf common/out
 rm -rf client/out
 rm -rf server/out
 rm -rf syntaxes/out

scripts/build.sh

@@ -9,10 +9,11 @@
 import * as ts from 'typescript/lib/tsserverlibrary';
 import * as lsp from 'vscode-languageserver';
 
+import {projectLoadingNotification} from '../../common/out/notifications';
+
 import {tsCompletionEntryToLspCompletionItem} from './completion';
 import {tsDiagnosticToLspDiagnostic} from './diagnostic';
 import {Logger} from './logger';
-import {projectLoadingNotification} from './protocol';
 import {ServerHost} from './server_host';
 import {filePathToUri, lspPositionToTsPosition, lspRangeToTsPositions, tsTextSpanToLspRange, uriToFilePath} from './utils';
 

server/src/session.ts

@@ -5,6 +5,9 @@
     "outDir": "out",
     "rootDir": "src"
   },
+  "references": [
+    {"path": "../common"}
+  ],
   "include": ["src/*.ts"],
   "exclude": [
     "src/banner.ts",