message: Warn on cycles. Test warnings.
diff: @@ -589,8 +589,15 @@ export class DocumentConverter {
  for (const htmlImport of this.getHtmlImports()) {
  const documentUrl = getDocumentUrl(htmlImport.document);
  const importedJsDocumentUrl = convertHtmlDocumentUrl(documentUrl);
  - if (this.visited.has(documentUrl) ||
  - this.analysisConverter.modules.has(importedJsDocumentUrl)) {
  + if (this.analysisConverter.modules.has(importedJsDocumentUrl)) {
  + continue;
  + }
  + if (this.visited.has(documentUrl)) {
  + console.warn(
  + `Cycle in dependency graph found where ` +
  + `${this.originalUrl} imports ${documentUrl}.\n` +
  + ` html2js does not yet support rewriting references among ` +
  + `cyclic dependencies.`);
  continue;
  }
  this.analysisConverter.convertDocument(htmlImport.document, this.visited);
  