Function updateImport

packages/language-service/src/utils/ts_utils.ts:656–694

(
  importDeclaration: ts.ImportDeclaration,
  localName: string,
  exportedSpecifierName: string | null,
)

 * is used as the default import name.
 */
export function updateImport(
  importDeclaration: ts.ImportDeclaration,
  localName: string,
  exportedSpecifierName: string | null,
): ts.ImportClause | undefined {
  const importClause = importDeclaration.importClause;
  if (importClause === undefined) {
    return undefined;
  }
  const bindings = importClause.namedBindings;
  if (bindings !== undefined && ts.isNamespaceImport(bindings)) {
    // This should be impossible. If a namespace import is present, the symbol was already
    // considered imported above.
    console.error(`Unexpected namespace import ${importDeclaration.getText()}`);
    return undefined;
  }
  if (localName === 'default' && exportedSpecifierName !== null) {
    const importClauseName = ts.factory.createIdentifier(exportedSpecifierName);
    return ts.factory.updateImportClause(
      importClause,
      false,
      importClauseName,
      importClause.namedBindings,
    );
  }
  let propertyName: ts.Identifier | undefined;
  if (exportedSpecifierName !== null && exportedSpecifierName !== localName) {
    propertyName = ts.factory.createIdentifier(exportedSpecifierName);
  }
  const name = ts.factory.createIdentifier(localName);
  const newImport = ts.factory.createImportSpecifier(false, propertyName, name);
  let namedImport: ts.NamedImports;
  if (bindings === undefined) {
    namedImport = ts.factory.createNamedImports([newImport]);
  } else {
    namedImport = ts.factory.updateNamedImports(bindings, [...bindings.elements, newImport]);
  }
  return ts.factory.updateImportClause(importClause, false, importClause.name, namedImport);
}

let printer: ts.Printer | null = null;