Add types for hbs npm package (#23091)

* Add types for hbs

* Use dtsg-gen generated tsconfig.json

* Add additional tests

* Now lints with less cheating

* Avoid losing type information

types/hbs/hbs-tests.ts

@@ -0,0 +1,29 @@
+import * as express from 'express';
+
+const app = express();
+
+app.set('view engine', 'html');
+
+import hbs = require('hbs');
+
+// The idiom for this is
+//   app.engine('html', require('hbs').__express);
+// However this undermines the test since the return type of require() is any
+app.engine('html', hbs.__express);
+
+hbs.registerHelper('helper_name', (testParm: number) => testParm++);
+hbs.registerPartial('partial_name', 'partial value');
+
+hbs.registerPartials(__dirname + '/views/partials');
+
+hbs.registerPartials(__dirname + '/views/partials', () => {});
+
+hbs.localsAsTemplateData(app);
+
+const safeString = new hbs.handlebars.SafeString("string");
+
+const instance1 = hbs.create();
+const instance2 = hbs.create();
+
+app.engine('html', instance1.__express);
+app.engine('hbs', instance2.__express);

types/hbs/index.d.ts

@@ -0,0 +1,26 @@
+// Type definitions for hbs 4.0
+// Project: https://github.com/pillarjs/hbs
+// Definitions by: David Muller <https://github.com/davidm77>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.3
+
+import handlebars = require('handlebars');
+
+type handlebarsModule = typeof handlebars;
+
+interface hbsModule {
+    readonly handlebars: handlebarsModule;
+    localsAsTemplateData(app: any): void;
+    registerHelper(helperName: string, helperFunction: (...args: any[]) => any): void;
+    registerPartial(partialName: string, partialValue: string): void;
+    registerPartials(directoryName: string, callback?: () => void): void;
+    __express(filename: string, options: any, cb: (...args: any[]) => any): any;
+}
+
+interface hbsModuleWithCreate extends hbsModule {
+    create(handlebars?: handlebarsModule): hbsModule;
+}
+
+declare var baseModule: hbsModuleWithCreate;
+
+export = baseModule;

types/hbs/tsconfig.json

@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "hbs-tests.ts"
+    ]
+}

types/hbs/tslint.json

@@ -0,0 +1,3 @@
+{
+    "extends": "dtslint/dt.json"
+}