code: function isStringLiteralArray(node) {
      return isArrayExpr(node) &&
             isArray(node.elements) &&
             node.elements.every(isStringLiteral);
  }
docs: Test if supplied `node` represents an array of string literals. Empty
  arrays are also valid here.
  @param   {ASTNode} node - ArrayExpression node to test
  @returns {Boolean} true if node represents an array of string literals