feat(language-server): answer HTML completion, hover, folding, and tag close

2026-08-18 20:43:47 +05:30
parent 6074d19c43
commit 609224591c
4 changed files with 239 additions and 1 deletions
@@ -0,0 +1,103 @@
+import { getLanguageService, TextDocument as HtmlTextDocument } from "vscode-html-languageservice";
+import { isInsideHtml, virtualHtmlDocument } from "./html-regions.ts";
+import { offsetAt, type Position, type TextDocument } from "./index.ts";
+
+export interface HtmlCompletionItem {
+  label: string;
+  kind: number;
+  detail?: string;
+  documentation?: string;
+  sortText?: string;
+  insertText?: string;
+}
+
+const service = getLanguageService();
+
+/** The virtual document as the HTML service's own document type. */
+function htmlDocument(document: TextDocument) {
+  const virtual = virtualHtmlDocument(document);
+  return HtmlTextDocument.create(virtual.uri, "html", document.version ?? 1, virtual.text);
+}
+
+function markdown(value: unknown): string {
+  if (typeof value === "string") return value;
+  if (value && typeof value === "object" && "value" in value) {
+    return String((value as { value: unknown }).value);
+  }
+  return "";
+}
+
+/**
+ * HTML completions for a position inside a view block.
+ *
+ * Every item carries the `1` sortText prefix so the server can rank WRNexus
+ * entries above these without filtering either list.
+ */
+export function htmlCompletions(document: TextDocument, position: Position): HtmlCompletionItem[] {
+  if (!isInsideHtml(document, offsetAt(document.text, position))) return [];
+
+  const virtual = htmlDocument(document);
+  const parsed = service.parseHTMLDocument(virtual);
+  const list = service.doComplete(virtual, position, parsed);
+
+  return list.items.map((item) => ({
+    label: item.label,
+    kind: typeof item.kind === "number" ? item.kind : 1,
+    detail: item.detail,
+    documentation: markdown(item.documentation),
+    sortText: `1${item.sortText ?? item.label}`,
+    insertText: item.textEdit && "newText" in item.textEdit ? item.textEdit.newText : undefined,
+  }));
+}
+
+export function htmlHover(document: TextDocument, position: Position): { contents: string } | null {
+  if (!isInsideHtml(document, offsetAt(document.text, position))) return null;
+
+  const virtual = htmlDocument(document);
+  const result = service.doHover(virtual, position, service.parseHTMLDocument(virtual));
+  if (!result) return null;
+
+  const contents = markdown(result.contents);
+  return contents ? { contents } : null;
+}
+
+export function htmlFoldingRanges(
+  document: TextDocument,
+): Array<{ startLine: number; endLine: number }> {
+  return service
+    .getFoldingRanges(htmlDocument(document))
+    .map((range) => ({ startLine: range.startLine, endLine: range.endLine }));
+}
+
+/**
+ * Detects `<Name attr="x" /` just before `position` and completes the `>`.
+ *
+ * `vscode-html-languageservice`'s own `doTagComplete` only reacts to a typed
+ * `/` when it opens an end tag (`</`); it has no notion of a self-closing
+ * start tag, since plain HTML has no such elements outside its fixed void-element
+ * list. WRNexus components (`<Card />`) are exactly that case, so we complete
+ * it ourselves rather than relying on the library.
+ */
+function selfClosingTagCompletion(text: string, offset: number): string | null {
+  if (text.charAt(offset - 1) !== "/") return null;
+  if (text.charAt(offset) === ">") return null;
+  const before = text.slice(0, offset);
+  return /<[A-Za-z][\w-]*(?:\s[^<>]*)?\/$/.test(before) ? ">" : null;
+}
+
+/**
+ * The snippet that closes the tag being typed, or null.
+ *
+ * Void elements and already-closed tags return null, which is why this decision
+ * belongs here rather than in the editor client.
+ */
+export function htmlTagComplete(document: TextDocument, position: Position): string | null {
+  const offset = offsetAt(document.text, position);
+  if (!isInsideHtml(document, offset)) return null;
+
+  const virtual = htmlDocument(document);
+  const result = service.doTagComplete(virtual, position, service.parseHTMLDocument(virtual));
+  if (result) return result;
+
+  return selfClosingTagCompletion(document.text, offset);
+}