build: Rewrite banner.js in TS (#446)

This commit removes the code duplication in banner.js by rewriting it in TS.
The workflow is as follows:

1. Compile banner.ts
2. rollup server/out/banner/banner.js to produce dist/server/banner.js
3. Compile the server
4. rollup server and concat banner.js to produce dist/server/index.js

In order to tree-shake unneeded code in banner.ts, a separate tsconfig
`server/banner.tsconfig.json` is needed to produce es2015 modules.

Author: Keen Yee Liau

banner.rollup.config.js

@@ -0,0 +1,13 @@
+module.exports = [
+  {
+    input: 'server/out/banner/banner.js',
+    output: {
+      file: 'dist/server/banner.js',
+      format: 'cjs',
+    },
+    external: [
+      'path',
+    ],
+  },
+
+];

package.json

@@ -28,7 +28,10 @@
       "title": "Angular Language Service",
       "properties": {
         "angular.ngdk": {
-          "type": ["string", "null"],
+          "type": [
+            "string",
+            "null"
+          ],
           "default": null,
           "description": "Specifies the folder path to @angular/language-service."
         },
@@ -52,7 +55,8 @@
   ],
   "main": "./client/out/extension",
   "scripts": {
-    "compile": "tsc -b && rollup -c",
+    "compile": "yarn compile:banner && tsc -b && rollup -c",
+    "compile:banner": "tsc -p server/banner.tsconfig.json && rollup -c banner.rollup.config.js",
     "compile:test": "tsc -b server/src/tests",
     "compile:integration": "tsc -b integration",
     "format": "scripts/format.sh",

rollup.config.js

@@ -23,7 +23,7 @@ module.exports = [
     output: {
       file: 'dist/server/index.js',
       format: 'amd',
-      banner: fs.readFileSync('server/src/banner.js', 'utf8'),
+      banner: fs.readFileSync('dist/server/banner.js', 'utf8'),
     },
     external: [
       'fs',

server/banner.tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "target": "es2015",
+    "module": "es2015",
+    "moduleResolution": "node",
+    "sourceMap": false,
+    "strict": true,
+    "outDir": "out/banner"
+  },
+  "files": [
+    "src/banner.ts"
+  ]
+}

server/src/banner.js

@@ -0,0 +1,25 @@
+import {parseCommandLine} from './cmdline_utils';
+
+/**
+ * This method provides a custom implementation for the AMD loader to resolve
+ * `typescript` module at runtime.
+ * @param modules modules to resolve
+ * @param cb function to invoke with resolved modules
+ */
+export function define(modules: string[], cb: (...modules: any[]) => void) {
+  function resolve(packageName: string, paths: string[]) {
+    try {
+      return require.resolve(packageName, {paths});
+    } catch {
+    }
+  }
+  const TSSERVER = 'typescript/lib/tsserverlibrary';
+  const resolvedModules = modules.map(m => {
+    if (m === TSSERVER || m === 'typescript') {
+      const {tsProbeLocations} = parseCommandLine(process.argv);
+      m = resolve(TSSERVER, tsProbeLocations) || TSSERVER;
+    }
+    return require(m);
+  });
+  cb(...resolvedModules);
+}

server/src/banner.ts

@@ -6,5 +6,8 @@
     "rootDir": "src"
   },
   "include": ["src/*.ts"],
-  "exclude": ["node_modules"]
+  "exclude": [
+    "src/banner.ts",
+    "node_modules"
+  ]
 }