text: var __extends = (this && this.__extends) || (function () {
      var extendStatics = Object.setPrototypeOf ||
          ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
          function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
      return function (d, b) {
          extendStatics(d, b);
          function __() { this.constructor = d; }
          d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
      };
  })();
  var __assign = (this && this.__assign) || Object.assign || function(t) {
      for (var s, i = 1, n = arguments.length; i < n; i++) {
          s = arguments[i];
          for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
              t[p] = s[p];
      }
      return t;
  };
  import { getOperationName } from 'apollo-utilities';
  import Observable from 'zen-observable-ts';
  import { print } from 'graphql/language/printer';
  export function validateOperation(operation) {
      var OPERATION_FIELDS = [
          'query',
          'operationName',
          'variables',
          'extensions',
          'context',
      ];
      for (var _i = 0, _a = Object.keys(operation); _i < _a.length; _i++) {
          var key = _a[_i];
          if (OPERATION_FIELDS.indexOf(key) < 0) {
              throw new Error("illegal argument: " + key);
          }
      }
      return operation;
  }
  var LinkError = /** @class */ (function (_super) {
      __extends(LinkError, _super);
      function LinkError(message, link) {
          var _this = _super.call(this, message) || this;
          _this.link = link;
          return _this;
      }
      return LinkError;
  }(Error));
  export { LinkError };
  export function isTerminating(link) {
      return link.request.length <= 1;
  }
  export function toPromise(observable) {
      var completed = false;
      return new Promise(function (resolve, reject) {
          observable.subscribe({
              next: function (data) {
                  if (completed) {
                      console.warn("Promise Wrapper does not support multiple results from Observable");
                  }
                  else {
                      completed = true;
                      resolve(data);
                  }
              },
              error: reject,
          });
      });
  }
  // backwards compat
  export var makePromise = toPromise;
  export function fromPromise(promise) {
      return new Observable(function (observer) {
          promise
              .then(function (value) {
              observer.next(value);
              observer.complete();
          })
              .catch(observer.error.bind(observer));
      });
  }
  export function fromError(errorValue) {
      return new Observable(function (observer) {
          observer.error(errorValue);
      });
  }
  export function transformOperation(operation) {
      var transformedOperation = {
          variables: operation.variables || {},
          extensions: operation.extensions || {},
          operationName: operation.operationName,
          query: operation.query,
      };
      // best guess at an operation name
      if (!transformedOperation.operationName) {
          transformedOperation.operationName =
              typeof transformedOperation.query !== 'string'
                  ? getOperationName(transformedOperation.query)
                  : '';
      }
      return transformedOperation;
  }
  export function createOperation(starting, operation) {
      var context = __assign({}, starting);
      var setContext = function (next) {
          if (typeof next === 'function') {
              context = __assign({}, context, next(context));
          }
          else {
              context = __assign({}, context, next);
          }
      };
      var getContext = function () { return (__assign({}, context)); };
      Object.defineProperty(operation, 'setContext', {
          enumerable: false,
          value: setContext,
      });
      Object.defineProperty(operation, 'getContext', {
          enumerable: false,
          value: getContext,
      });
      Object.defineProperty(operation, 'toKey', {
          enumerable: false,
          value: function () { return getKey(operation); },
      });
      return operation;
  }
  export function getKey(operation) {
      // XXX we're assuming here that variables will be serialized in the same order.
      // that might not always be true
      return print(operation.query) + "|" + JSON.stringify(operation.variables) + "|" + operation.operationName;
  }
  //# sourceMappingURL=linkUtils.js.map