fix(language-service): use the HtmlAst to get the span of HTML tag (#36371)

The HTML tag may include `-` (e.g. `app-root`), so use the `HtmlAst` to get the span.

PR Close #36371

Author: ivanwonder

packages/language-service/src/completions.ts

@@ -55,12 +55,22 @@ function isIdentifierPart(code: number) {
  * Gets the span of word in a template that surrounds `position`. If there is no word around
  * `position`, nothing is returned.
  */
-function getBoundedWordSpan(templateInfo: AstResult, position: number): ts.TextSpan|undefined {
+function getBoundedWordSpan(
+    templateInfo: AstResult, position: number, ast: HtmlAst|undefined): ts.TextSpan|undefined {
   const {template} = templateInfo;
   const templateSrc = template.source;
 
   if (!templateSrc) return;
 
+  if (ast instanceof Element) {
+    // The HTML tag may include `-` (e.g. `app-root`),
+    // so use the HtmlAst to get the span before ayazhafiz refactor the code.
+    return {
+      start: templateInfo.template.span.start + ast.startSourceSpan!.start.offset + 1,
+      length: ast.name.length
+    };
+  }
+
   // TODO(ayazhafiz): A solution based on word expansion will always be expensive compared to one
   // based on ASTs. Whatever penalty we incur is probably manageable for small-length (i.e. the
   // majority of) identifiers, but the current solution involes a number of branchings and we can't
@@ -185,7 +195,7 @@ export function getTemplateCompletions(
         null);
   }
 
-  const replacementSpan = getBoundedWordSpan(templateInfo, position);
+  const replacementSpan = getBoundedWordSpan(templateInfo, position, mostSpecific);
   return result.map(entry => {
     return {
       ...entry,

packages/language-service/test/completions_spec.ts

@@ -670,18 +670,18 @@ describe('completions', () => {
         @Component({
           selector: 'foo-component',
           template: \`
-            <di~{div}></div>
+            <test-comp~{test-comp}></test-comp>
           \`,
         })
         export class FooComponent {}
       `);
-      const location = mockHost.getLocationMarkerFor(fileName, 'div');
+      const location = mockHost.getLocationMarkerFor(fileName, 'test-comp');
       const completions = ngLS.getCompletionsAtPosition(fileName, location.start)!;
       expect(completions).toBeDefined();
-      const completion = completions.entries.find(entry => entry.name === 'div')!;
+      const completion = completions.entries.find(entry => entry.name === 'test-comp')!;
       expect(completion).toBeDefined();
-      expect(completion.kind).toBe('html element');
-      expect(completion.replacementSpan).toEqual({start: location.start - 2, length: 2});
+      expect(completion.kind).toBe('component');
+      expect(completion.replacementSpan).toEqual({start: location.start - 9, length: 9});
     });
 
     it('should work for bindings', () => {