How to use the @nrwl/workspace/src/utils/ast-utils.findNodes function in @nrwl/workspace

ts.SyntaxKind.CallExpression
  ) as ts.CallExpression[];

  for (const expr of calls) {
    const inner = expr.expression;
    if (
      ts.isPropertyAccessExpression(inner) &&
      /ReactDOM/i.test(inner.expression.getText()) &&
      inner.name.getText() === 'render'
    ) {
      return expr;
    }
  }

  // 2. Try to find render from 'react-dom'.
  const imports = findNodes(
    source,
    ts.SyntaxKind.ImportDeclaration
  ) as ts.ImportDeclaration[];
  const hasRenderImport = imports.some(
    i =>
      i.moduleSpecifier.getText().includes('react-dom') &&
      /\brender\b/.test(i.importClause.namedBindings.getText())
  );
  if (hasRenderImport) {
    const calls = findNodes(
      source,
      ts.SyntaxKind.CallExpression
    ) as ts.CallExpression[];
    for (const expr of calls) {
      if (expr.expression.getText() === 'render') {
        return expr;

export function findMainRenderStatement(
  source: ts.SourceFile
): ts.CallExpression | null {
  // 1. Try to find ReactDOM.render.
  const calls = findNodes(
    source,
    ts.SyntaxKind.CallExpression
  ) as ts.CallExpression[];

  for (const expr of calls) {
    const inner = expr.expression;
    if (
      ts.isPropertyAccessExpression(inner) &&
      /ReactDOM/i.test(inner.expression.getText()) &&
      inner.name.getText() === 'render'
    ) {
      return expr;
    }
  }

  // 2. Try to find render from 'react-dom'.

export function findElements(source: ts.SourceFile, tagName: string) {
  const nodes = findNodes(source, [
    ts.SyntaxKind.JsxSelfClosingElement,
    ts.SyntaxKind.JsxOpeningElement
  ]);
  return nodes.filter(node => isTag(tagName, node));
}

export function findDefaultExportDeclaration(
  source: ts.SourceFile
): ts.Node | null {
  const identifier = findDefaultExportIdentifier(source);

  if (identifier) {
    const variables = findNodes(source, ts.SyntaxKind.VariableDeclaration);
    const fns = findNodes(source, ts.SyntaxKind.FunctionDeclaration);
    const all = variables.concat(fns) as Array<
      ts.VariableDeclaration | ts.FunctionDeclaration
    >;

    const exported = all
      .filter(x => x.name.kind === ts.SyntaxKind.Identifier)
      .find(x => (x.name as ts.Identifier).text === identifier.text);

    return exported || null;
  } else {
    return null;
  }
}

export function findDefaultClassOrFunction(
  source: ts.SourceFile
): ts.FunctionDeclaration | ts.ClassDeclaration | null {
  const fns = findNodes(
    source,
    ts.SyntaxKind.FunctionDeclaration
  ) as ts.FunctionDeclaration[];
  const cls = findNodes(
    source,
    ts.SyntaxKind.ClassDeclaration
  ) as ts.ClassDeclaration[];

  return (
    fns.find(hasDefaultExportModifier) ||
    cls.find(hasDefaultExportModifier) ||
    null
  );
}

export function findDefaultExportDeclaration(
  source: ts.SourceFile
): ts.Node | null {
  const identifier = findDefaultExportIdentifier(source);

  if (identifier) {
    const variables = findNodes(source, ts.SyntaxKind.VariableDeclaration);
    const fns = findNodes(source, ts.SyntaxKind.FunctionDeclaration);
    const all = variables.concat(fns) as Array<
      ts.VariableDeclaration | ts.FunctionDeclaration
    >;

    const exported = all
      .filter(x => x.name.kind === ts.SyntaxKind.Identifier)
      .find(x => (x.name as ts.Identifier).text === identifier.text);

    return exported || null;
  } else {
    return null;
  }
}