Add initial custom-element standard snippet

CHANGELOG.md

@@ -31,6 +31,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   - New setting `polymer-ide.logToFile`, a string path to a file. When given,
     logs are appended to this file (in addition to possibly going to the
     client).
+- Add autocompletion for standard custom element definition.
 
 ## 2.0.0 - 2017-12-05
 

src/language-server/auto-completer.ts

@@ -24,6 +24,7 @@ import {LsAnalyzer} from './analyzer-synchronizer';
 import AnalyzerLSPConverter from './converter';
 import FeatureFinder, {DatabindingFeature} from './feature-finder';
 import {Handler} from './util';
+import {standardJavaScriptSnippets} from '../standard-snippets';
 
 
 /**
@@ -115,6 +116,11 @@ export default class AutoCompleter extends Handler {
       if (location.kind === 'attribute') {
         return this.getAttributeCompletions(document, location);
       }
+      // TODO(timvdlippe): Also return these snippets if the user is in a
+      // javascript file (locResult.language === 'js')
+      if (location.kind === 'scriptTagContents') {
+        return this.getStandardJavaScriptSnippetCompletions();
+      }
     }
   }
 
@@ -378,6 +384,13 @@ export default class AutoCompleter extends Handler {
     };
   }
 
+  private getStandardJavaScriptSnippetCompletions(): CompletionList {
+    return {
+      isIncomplete: false,
+      items: standardJavaScriptSnippets
+    };
+  }
+
   private createSortPrefixes(element: Element): Map<string|undefined, string> {
     // A map from the inheritedFrom to a sort prefix. Note that
     // `undefined` is a legal value for inheritedFrom.

src/standard-snippets.ts

@@ -0,0 +1,34 @@
+/**
+ * Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
+ * This code may only be used under the BSD style license found at
+ * http://polymer.github.io/LICENSE.txt
+ * The complete set of authors may be found at
+ * http://polymer.github.io/AUTHORS.txt
+ * The complete set of contributors may be found at
+ * http://polymer.github.io/CONTRIBUTORS.txt
+ * Code distributed by Google as part of the polymer project is also
+ * subject to an additional IP rights grant found at
+ * http://polymer.github.io/PATENTS.txt
+ */
+
+import {CompletionItemKind, InsertTextFormat} from 'vscode-languageserver';
+
+export const standardJavaScriptSnippets = [
+  {
+    label: `custom-element`,
+    documentation: 'Snippet for definition of a custom-element.',
+    insertText:
+`class $1 extends HTMLElement {
+  constructor() {
+    super();
+    $0
+  }
+}
+customElements.define('$2', $1)`,
+    insertTextFormat: InsertTextFormat.Snippet,
+    kind: CompletionItemKind.Class,
+    filterText: 'customelement',
+  }
+];
+
+export default standardJavaScriptSnippets;

src/test/auto-completer_test.ts

@@ -19,6 +19,7 @@ import {ResolvedUrl} from 'polymer-analyzer/lib/model/url';
 import {CompletionItem, CompletionItemKind, CompletionList, InsertTextFormat} from 'vscode-languageserver/lib/main';
 
 import {createTestEnvironment} from './util';
+import {standardJavaScriptSnippets} from '../standard-snippets';
 
 const fixtureDir = path.join(__dirname, '..', '..', 'src', 'test', 'static');
 
@@ -432,12 +433,12 @@ suite('AutoCompleter', () => {
         {isIncomplete: false, items: attributeCompletions});
   });
 
-  test(`Don't give HTML completions inside of script tags.`, async() => {
+  test(`Return JavaScript standard completions inside of script tags.`, async() => {
     const {client} = await createTestEnvironment(fixtureDir);
     await client.openFile(indexFile, '<script>\n\n</script>\n' + indexContents);
     const completions =
         await client.getCompletions(indexFile, {line: 1, column: 0});
-    assert.deepEqual(completions, {isIncomplete: true, items: []});
+    assert.deepEqual(completions, {isIncomplete: false, items: standardJavaScriptSnippets});
   });
 
   {