How to use the esprima-fb.Syntax.ExpressionStatement function in esprima-fb

function visitArrowFunction(traverse, node, path, state) {
  var notInExpression = (path[0].type === Syntax.ExpressionStatement);

  // Wrap a function into a grouping operator, if it's not
  // in the expression position.
  if (notInExpression) {
    utils.append('(', state);
  }

  utils.append('function', state);
  renderParams(traverse, node, path, state);

  // Skip arrow.
  utils.catchupWhiteSpace(node.body.range[0], state);

  var renderBody = node.body.type == Syntax.BlockStatement
    ? renderStatementBody
    : renderExpressionBody;

visitStructuredAssignment.test = function(node, path, state) {
  // We consider the expression statement rather than just assignment
  // expression to cover case with object patters which should be
  // wrapped in grouping operator: ({x, y} = {y, x});
  return node.type === Syntax.ExpressionStatement &&
    node.expression.type === Syntax.AssignmentExpression &&
    isStructuredPattern(node.expression.left);
};

function visitArrowFunction(traverse, node, path, state) {
  var notInExpression = (path[0].type === Syntax.ExpressionStatement);

  // Wrap a function into a grouping operator, if it's not
  // in the expression position.
  if (notInExpression) {
    utils.append('(', state);
  }

  utils.append('function', state);
  renderParams(traverse, node, path, state);

  // Skip arrow.
  utils.catchupWhiteSpace(node.body.range[0], state);

  var renderBody = node.body.type == Syntax.BlockStatement
    ? renderStatementBody
    : renderExpressionBody;

function visitArrowFunction(traverse, node, path, state) {
  var notInExpression = (path[0].type === Syntax.ExpressionStatement);

  // Wrap a function into a grouping operator, if it's not
  // in the expression position.
  if (notInExpression) {
    utils.append('(', state);
  }

  utils.append('function', state);
  renderParams(traverse, node, path, state);

  // Skip arrow.
  utils.catchupWhiteSpace(node.body.range[0], state);

  var renderBody = node.body.type == Syntax.BlockStatement
    ? renderStatementBody
    : renderExpressionBody;

function visitArrowFunction(traverse, node, path, state) {
  var notInExpression = (path[0].type === Syntax.ExpressionStatement);

  // Wrap a function into a grouping operator, if it's not
  // in the expression position.
  if (notInExpression) {
    utils.append('(', state);
  }

  utils.append('function', state);
  renderParams(traverse, node, path, state);

  // Skip arrow.
  utils.catchupWhiteSpace(node.body.range[0], state);

  var renderBody = node.body.type == Syntax.BlockStatement
    ? renderStatementBody
    : renderExpressionBody;

function visitArrowFunction(traverse, node, path, state) {
  var notInExpression = (path[0].type === Syntax.ExpressionStatement);

  // Wrap a function into a grouping operator, if it's not
  // in the expression position.
  if (notInExpression) {
    utils.append('(', state);
  }

  utils.append('function', state);
  renderParams(traverse, node, path, state);

  // Skip arrow.
  utils.catchupWhiteSpace(node.body.range[0], state);

  var renderBody = node.body.type == Syntax.BlockStatement
    ? renderStatementBody
    : renderExpressionBody;

function visitArrowFunction(traverse, node, path, state) {
  var notInExpression = (path[0].type === Syntax.ExpressionStatement);

  // Wrap a function into a grouping operator, if it's not
  // in the expression position.
  if (notInExpression) {
    utils.append('(', state);
  }

  utils.append('function', state);
  renderParams(traverse, node, path, state);

  // Skip arrow.
  utils.catchupWhiteSpace(node.body.range[0], state);

  var renderBody = node.body.type == Syntax.BlockStatement
    ? renderStatementBody
    : renderExpressionBody;

visitStructuredAssignment.test = function(node, path, state) {
  // We consider the expression statement rather than just assignment
  // expression to cover case with object patters which should be
  // wrapped in grouping operator: ({x, y} = {y, x});
  return node.type === Syntax.ExpressionStatement &&
    node.expression.type === Syntax.AssignmentExpression &&
    isStructuredPattern(node.expression.left);
};

function visitArrowFunction(traverse, node, path, state) {
  var notInExpression = (path[0].type === Syntax.ExpressionStatement);

  // Wrap a function into a grouping operator, if it's not
  // in the expression position.
  if (notInExpression) {
    utils.append('(', state);
  }

  utils.append('function', state);
  renderParams(traverse, node, path, state);

  // Skip arrow.
  utils.catchupWhiteSpace(node.body.range[0], state);

  var renderBody = node.body.type == Syntax.BlockStatement
    ? renderStatementBody
    : renderExpressionBody;

visitRegisterExpression.test = function(node, path, state) {
    return (node.type === Syntax.ExpressionStatement && node.expression.type === Syntax.ObjectExpression)
        || (node.type === Syntax.CallExpression
            && node.callee.type === Syntax.MemberExpression && node.callee.object.name === 'Bosonic'
            && node.callee.property.name === 'register'
            && node.arguments[0].type === Syntax.ObjectExpression);
};