test(language-service): Add external template (#30128)

This is in preparation for more rigorous testing of external templates, since it'll work differently under the new tsserver plugin model.

PR Close #30128

integration/language_service_plugin/goldens/quickinfo_externalTemplate.json

@@ -0,0 +1,22 @@
+{
+  "seq": 0,
+  "type": "response",
+  "command": "quickinfo",
+  "request_seq": 4,
+  "success": true,
+  "body": {
+    "kind": "const",
+    "kindModifiers": "declare",
+    "start": {
+      "line": 1,
+      "offset": 17
+    },
+    "end": {
+      "line": 1,
+      "offset": 21
+    },
+    "displayString": "const name: never",
+    "documentation": "",
+    "tags": []
+  }
+}

integration/language_service_plugin/project/app/app.component.ts

@@ -2,6 +2,6 @@ import { Component } from '@angular/core';
 
 @Component({
   selector: 'my-app',
-  template: `<h1>Hello {{name}}</h1>`,
+  template: `<h1>Hello {{name}}</h1><my-widget></my-widget>`,
 })
 export class AppComponent  { name = 'Angular'; }

integration/language_service_plugin/project/app/app.module.ts

@@ -2,10 +2,11 @@ import { NgModule }      from '@angular/core';
 import { BrowserModule } from '@angular/platform-browser';
 
 import { AppComponent }  from './app.component';
+import { WidgetComponent } from './widget.component';
 
 @NgModule({
   imports:      [ BrowserModule ],
-  declarations: [ AppComponent ],
+  declarations: [ AppComponent, WidgetComponent ],
   bootstrap:    [ AppComponent ]
 })
 export class AppModule { }

integration/language_service_plugin/project/app/widget.component.html

@@ -0,0 +1 @@
+<h1>This is a {{name}} widget!</h1>

integration/language_service_plugin/project/app/widget.component.ts

@@ -0,0 +1,7 @@
+import { Component } from '@angular/core';
+
+@Component({
+  selector: 'my-widget',
+  templateUrl: './widget.component.html',
+})
+export class WidgetComponent  { name = 'Angular'; }

integration/language_service_plugin/test.ts

@@ -118,6 +118,17 @@ describe('Angular Language Service', () => {
       offset: 28,
     });
     expect(resp2).toMatchGolden('quickinfo.json');
+
+    client.sendRequest('open', {
+      file: `${PWD}/project/app/widget.component.html`,
+    });
+
+    const resp3 = await client.sendRequest('quickinfo', {
+      file: `${PWD}/project/app/widget.component.html`,
+      line: 1,
+      offset: 19,
+    });
+    expect(resp3).toMatchGolden('quickinfo_externalTemplate.json');
   });
 
   it('should perform definition', async () => {