@data-client/core/dist/index.js

Async State Management without the Management. REST, GraphQL, SSE, Websockets, Fetch

'use strict';

var normalizr = require('@data-client/normalizr');

function expireReducer(state, action) {
  const meta = {
    ...state.meta
  };
  Object.keys(meta).forEach(key => {
    if (action.testKey(key)) {
      meta[key] = {
        ...meta[key],
        // 1 instead of 0 so we can do 'falsy' checks to see if it is set
        expiresAt: 1
      };
    }
  });
  return {
    ...state,
    meta
  };
}

function createMeta(expiryLength, fetchedAt) {
  const now = Date.now();
  return {
    fetchedAt: fetchedAt != null ? fetchedAt : now,
    date: now,
    expiresAt: now + expiryLength
  };
}

const FETCH = 'rdc/fetch';
const SET = 'rdc/set';
const SET_RESPONSE = 'rdc/setresponse';
const OPTIMISTIC = 'rdc/optimistic';
const RESET = 'rdc/reset';
const SUBSCRIBE = 'rdc/subscribe';
const UNSUBSCRIBE = 'rdc/unsubscribe';
const INVALIDATE = 'rdc/invalidate';
const INVALIDATEALL = 'rdc/invalidateall';
const EXPIREALL = 'rdc/expireall';
const GC = 'rdc/gc';
const FETCH_TYPE = FETCH;
const SET_TYPE = SET;
const SET_RESPONSE_TYPE = SET_RESPONSE;
const OPTIMISTIC_TYPE = OPTIMISTIC;
const RESET_TYPE = RESET;
const SUBSCRIBE_TYPE = SUBSCRIBE;
const UNSUBSCRIBE_TYPE = UNSUBSCRIBE;
const INVALIDATE_TYPE = INVALIDATE;
const INVALIDATEALL_TYPE = INVALIDATEALL;
const EXPIREALL_TYPE = EXPIREALL;
const GC_TYPE = GC;

var actionTypes = /*#__PURE__*/Object.freeze({
  __proto__: null,
  EXPIREALL: EXPIREALL,
  EXPIREALL_TYPE: EXPIREALL_TYPE,
  FETCH: FETCH,
  FETCH_TYPE: FETCH_TYPE,
  GC: GC,
  GC_TYPE: GC_TYPE,
  INVALIDATE: INVALIDATE,
  INVALIDATEALL: INVALIDATEALL,
  INVALIDATEALL_TYPE: INVALIDATEALL_TYPE,
  INVALIDATE_TYPE: INVALIDATE_TYPE,
  OPTIMISTIC: OPTIMISTIC,
  OPTIMISTIC_TYPE: OPTIMISTIC_TYPE,
  RESET: RESET,
  RESET_TYPE: RESET_TYPE,
  SET: SET,
  SET_RESPONSE: SET_RESPONSE,
  SET_RESPONSE_TYPE: SET_RESPONSE_TYPE,
  SET_TYPE: SET_TYPE,
  SUBSCRIBE: SUBSCRIBE,
  SUBSCRIBE_TYPE: SUBSCRIBE_TYPE,
  UNSUBSCRIBE: UNSUBSCRIBE,
  UNSUBSCRIBE_TYPE: UNSUBSCRIBE_TYPE
});

const ensurePojo =
// FormData doesn't exist in node
/* istanbul ignore else we don't run coverage when we test node*/
typeof FormData !== 'undefined' ? body => body instanceof FormData ? Object.fromEntries(body.entries()) : body : /* istanbul ignore next */body => body;

function createOptimistic(endpoint, args, fetchedAt) {
  var _endpoint$dataExpiryL, _endpoint$dataExpiryL2;
  /* istanbul ignore next */
  if (process.env.NODE_ENV === 'development' && ((_endpoint$dataExpiryL = endpoint.dataExpiryLength) != null ? _endpoint$dataExpiryL : 0) < 0) {
    throw new Error('Negative expiry length are not allowed.');
  }
  return {
    type: OPTIMISTIC,
    key: endpoint.key(...args),
    args: args.map(ensurePojo),
    endpoint,
    meta: createMeta((_endpoint$dataExpiryL2 = endpoint.dataExpiryLength) != null ? _endpoint$dataExpiryL2 : 60000, fetchedAt)
  };
}

function fetchReducer(state, action) {
  if (action.endpoint.getOptimisticResponse && action.endpoint.sideEffect) {
    const setAction = createOptimistic(action.endpoint, action.args, action.meta.fetchedAt);
    return {
      ...state,
      optimistic: [...state.optimistic, setAction]
    };
  }
  return state;
}

function invalidateReducer(state, action) {
  const endpoints = {
    ...state.endpoints
  };
  const meta = {
    ...state.meta
  };
  const invalidateKey = key => {
    delete endpoints[key];
    const itemMeta = {
      ...meta[key],
      expiresAt: 0,
      invalidated: true
    };
    delete itemMeta.error;
    meta[key] = itemMeta;
  };
  if (action.type === INVALIDATE) {
    invalidateKey(action.key);
  } else {
    Object.keys(endpoints).forEach(key => {
      if (action.testKey(key)) {
        invalidateKey(key);
      }
    });
  }
  return {
    ...state,
    endpoints,
    meta
  };
}

function setReducer(state, action, controller) {
  let value;
  if (typeof action.value === 'function') {
    const previousValue = controller.get(action.schema, ...action.args, state);
    if (previousValue === undefined) return state;
    value = action.value(previousValue);
  } else {
    value = action.value;
  }
  try {
    const {
      entities,
      indexes,
      entitiesMeta
    } = normalizr.normalize(action.schema, value, action.args, state, action.meta);
    return {
      entities,
      endpoints: state.endpoints,
      indexes,
      meta: state.meta,
      entitiesMeta,
      optimistic: state.optimistic,
      lastReset: state.lastReset
    };
    // reducer must update the state, so in case of processing errors we simply compute the endpoints inline
  } catch (error) {
    // this is not always bubbled up, so let's double sure this doesn't fail silently
    /* istanbul ignore else */
    if (process.env.NODE_ENV !== 'production') {
      console.error(error);
    }
    return state;
  }
}

class AbortOptimistic extends Error {}

function setResponseReducer(state, action, controller) {
  if (action.error) {
    return reduceError(state, action, action.response);
  }
  try {
    var _state$meta$action$ke;
    let response;
    // for true set's response is contained in action
    if (action.type === OPTIMISTIC) {
      // this should never happen
      /* istanbul ignore if */
      if (!action.endpoint.getOptimisticResponse) return state;
      try {
        // compute optimistic response based on current state
        response = action.endpoint.getOptimisticResponse.call(action.endpoint, controller.snapshot(state, action.meta.fetchedAt), ...action.args);
      } catch (e) {
        // AbortOptimistic means 'do nothing', otherwise we count the exception as endpoint failure
        if (e.constructor === AbortOptimistic) {
          return state;
        }
        throw e;
      }
    } else {
      response = action.response;
    }
    const {
      result,
      entities,
      indexes,
      entitiesMeta
    } = normalizr.normalize(action.endpoint.schema, response, action.args, state, action.meta);
    const endpoints = {
      ...state.endpoints,
      [action.key]: result
    };
    try {
      if (action.endpoint.update) {
        const updaters = action.endpoint.update(result, ...action.args);
        Object.keys(updaters).forEach(key => {
          endpoints[key] = updaters[key](endpoints[key]);
        });
      }
      // no reason to completely fail because of user-code error
      // integrity of this state update is still guaranteed
    } catch (error) {
      console.error(`Endpoint.update() error: ${action.key}`);
      console.error(error);
    }
    return {
      entities,
      endpoints,
      indexes,
      meta: {
        ...state.meta,
        [action.key]: {
          date: action.meta.date,
          fetchedAt: action.meta.fetchedAt,
          expiresAt: action.meta.expiresAt,
          prevExpiresAt: (_state$meta$action$ke = state.meta[action.key]) == null ? void 0 : _state$meta$action$ke.expiresAt
        }
      },
      entitiesMeta,
      optimistic: filterOptimistic(state, action),
      lastReset: state.lastReset
    };
    // reducer must update the state, so in case of processing errors we simply compute the endpoints inline
  } catch (error) {
    if (typeof error === 'object') {
      error.message = `Error processing ${action.key}\n\nFull Schema: ${JSON.stringify(action.endpoint.schema, undefined, 2)}\n\nError:\n${error.message}`;
      if ('response' in action) error.response = action.response;
      error.status = 400;
    }

    // this is not always bubbled up, so let's double sure this doesn't fail silently
    /* istanbul ignore else */
    if (process.env.NODE_ENV !== 'production') {
      console.error(error);
    }
    return reduceError(state, action, error);
  }
}
function reduceError(state, action, error) {
  if (error.name === 'AbortError') {
    // In case we abort simply undo the optimistic update and act like no fetch even occured
    // We still want those watching promises from fetch directly to observed the abort, but we don't want to
    // Trigger errors in this case. This means theoretically improperly built aborts useSuspense() could suspend forever.
    return {
      ...state,
      optimistic: filterOptimistic(state, action)
    };
  }
  return {
    ...state,
    meta: {
      ...state.meta,
      [action.key]: {
        date: action.meta.date,
        fetchedAt: action.meta.fetchedAt,
        expiresAt: action.meta.expiresAt,
        error,
        errorPolicy: action.endpoint.errorPolicy == null ? void 0 : action.endpoint.errorPolicy(error)
      }
    },
    optimistic: filterOptimistic(state, action)
  };
}
/** Filter all requests with same serialization that did not start after the resolving request */
function filterOptimistic(state, resolvingAction) {
  return state.optimistic.filter(optimisticAction => optimisticAction.key !== resolvingAction.key || (optimisticAction.type === OPTIMISTIC ? optimisticAction.meta.fetchedAt !== resolvingAction.meta.fetchedAt : optimisticAction.meta.date > resolvingAction.meta.date));
}

function createReducer(controller) {
  return function reducer(state, action) {
    if (!state) state = initialState;
    switch (action.type) {
      case GC:
        // inline deletes are fine as these should have 0 refcounts
        action.entities.forEach(({
          key,
          pk
        }) => {
          var _entities$key, _entitiesMeta$key;
          (_entities$key = state.entities[key]) == null || delete _entities$key[pk];
          (_entitiesMeta$key = state.entitiesMeta[key]) == null || delete _entitiesMeta$key[pk];
        });
        action.endpoints.forEach(fetchKey => {
          delete state.endpoints[fetchKey];
          delete state.meta[fetchKey];
        });
        return state;
      case FETCH:
        return fetchReducer(state, action);
      case OPTIMISTIC:
      // eslint-disable-next-line no-fallthrough
      case SET_RESPONSE:
        return setResponseReducer(state, action, controller);
      case SET:
        return setReducer(state, action, controller);
      case INVALIDATEALL:
      case INVALIDATE:
        return invalidateReducer(state, action);
      case EXPIREALL:
        return expireReducer(state, action);
      case RESET:
        return {
          ...initialState,
          lastReset: action.date
        };
      default:
        // A reducer must always return a valid state.
        // Alternatively you can throw an error if an invalid action is dispatched.
        return state;
    }
  };
}
const initialState = {
  entities: {},
  endpoints: {},
  indexes: {},
  meta: {},
  entitiesMeta: {},
  optimistic: [],
  lastReset: 0
};

var internal = /*#__PURE__*/Object.freeze({
  __proto__: null,
  INVALID: normalizr.INVALID,
  MemoCache: normalizr.MemoCache,
  initialState: initialState
});

function createSubscription(endpoint, {
  args
}) {
  return {
    type: SUBSCRIBE,
    key: endpoint.key(...args),
    args,
    endpoint
  };
}
function createUnsubscription(endpoint, {
  args
}) {
  return {
    type: UNSUBSCRIBE,
    key: endpoint.key(...args),
    args,
    endpoint
  };
}

function createSetResponse(endpoint, {
  args,
  fetchedAt,
  response,
  error = false
}) {
  var _endpoint$errorExpiry, _endpoint$dataExpiryL;
  const expiryLength = error ? (_endpoint$errorExpiry = endpoint.errorExpiryLength) != null ? _endpoint$errorExpiry : 1000 : (_endpoint$dataExpiryL = endpoint.dataExpiryLength) != null ? _endpoint$dataExpiryL : 60000;
  /* istanbul ignore next */
  if (process.env.NODE_ENV === 'development' && expiryLength < 0) {
    throw new Error('Negative expiry length are not allowed.');
  }
  return {
    type: SET_RESPONSE,
    key: endpoint.key(...args),
    response,
    args: args.map(ensurePojo),
    endpoint,
    meta: createMeta(expiryLength, fetchedAt),
    error
  };
}

function createSet(schema, {
  args,
  fetchedAt,
  value
}) {
  return {
    type: SET,
    value,
    args: args.map(ensurePojo),
    schema,
    meta: createMeta(60000, fetchedAt)
  };
}

function createReset() {
  return {
    type: RESET,
    date: Date.now()
  };
}

function createInvalidateAll(testKey) {
  return {
    type: INVALIDATEALL,
    testKey
  };
}

function createInvalidate(endpoint, {
  args
}) {
  return {
    type: INVALIDATE,
    key: endpoint.key(...args)
  };
}

/**
 * Requesting a fetch to begin
 */
function createFetch(endpoint, {
  args
}) {
  let resolve = 0;
  let reject = 0;
  const promise = new Promise((a, b) => {
    [resolve, reject] = [a, b];
  });
  const meta = {
    fetchedAt: Date.now(),
    resolve,
    reject,
    promise
  };
  return {
    type: FETCH,
    key: endpoint.key(...args),
    args,
    endpoint,
    meta
  };
}

function createExpireAll(testKey) {
  return {
    type: EXPIREALL,
    testKey
  };
}

var index = /*#__PURE__*/Object.freeze({
  __proto__: null,
  createExpireAll: createExpireAll,
  createFetch: createFetch,
  createInvalidate: createInvalidate,
  createInvalidateAll: createInvalidateAll,
  createMeta: createMeta,
  createOptimistic: createOptimistic,
  createReset: createReset,
  createSet: createSet,
  createSetResponse: createSetResponse,
  createSubscription: createSubscription,
  createUnsubscription: createUnsubscription
});

class GCPolicy {
  endpointCount = new Map();
  entityCount = new Map();
  endpointsQ = new Set();
  entitiesQ = [];
  constructor({
    // every 5 min
    intervalMS = 60 * 1000 * 5,
    expiryMultiplier = 2,
    expiresAt
  } = {}) {
    if (expiresAt) {
      this.expiresAt = expiresAt.bind(this);
    }
    this.options = {
      intervalMS,
      expiryMultiplier
    };
  }
  init(controller) {
    this.controller = controller;
    this.intervalId = setInterval(() => {
      this.idleCallback(() => this.runSweep(), {
        timeout: 1000
      });
    }, this.options.intervalMS);
    if (typeof this.intervalId === 'object' && 'unref' in this.intervalId) {
      this.intervalId.unref();
    }
  }
  cleanup() {
    clearInterval(this.intervalId);
  }
  createCountRef({
    key,
    paths = []
  }) {
    // increment
    return () => {
      var _this$endpointCount$g;
      if (key) this.endpointCount.set(key, ((_this$endpointCount$g = this.endpointCount.get(key)) != null ? _this$endpointCount$g : 0) + 1);
      paths.forEach(path => {
        var _instanceCount$get;
        const {
          key,
          pk
        } = path;
        if (!this.entityCount.has(key)) {
          this.entityCount.set(key, new Map());
        }
        const instanceCount = this.entityCount.get(key);
        instanceCount.set(pk, ((_instanceCount$get = instanceCount.get(pk)) != null ? _instanceCount$get : 0) + 1);
      });

      // decrement
      return () => {
        if (key) {
          const currentCount = this.endpointCount.get(key);
          if (currentCount !== undefined) {
            if (currentCount <= 1) {
              this.endpointCount.delete(key);
              // queue for cleanup
              this.endpointsQ.add(key);
            } else {
              this.endpointCount.set(key, currentCount - 1);
            }
          }
        }
        paths.forEach(path => {
          const {
            key,
            pk
          } = path;
          if (!this.entityCount.has(key)) {
            return;
          }
          const instanceCount = this.entityCount.get(key);
          const entityCount = instanceCount.get(pk);
          if (entityCount !== undefined) {
            if (entityCount <= 1) {
              instanceCount.delete(pk);
              // queue for cleanup
              this.entitiesQ.push(path);
            } else {
              instanceCount.set(pk, entityCount - 1);
            }
          }
        });
      };
    };
  }
  expiresAt({
    fetchedAt,
    expiresAt
  }) {
    return Math.max((expiresAt - fetchedAt) * this.options.expiryMultiplier, 120000) + fetchedAt;
  }
  runSweep() {
    const state = this.controller.getState();
    const entities = [];
    const endpoints = [];
    const now = Date.now();
    const nextEndpointsQ = new Set();
    for (const key of this.endpointsQ) {
      var _state$meta$key;
      if (!this.endpointCount.has(key) && this.expiresAt((_state$meta$key = state.meta[key]) != null ? _state$meta$key : {
        fetchedAt: 0,
        date: 0,
        expiresAt: 0
      }) < now) {
        endpoints.push(key);
      } else {
        nextEndpointsQ.add(key);
      }
    }
    this.endpointsQ = nextEndpointsQ;
    const nextEntitiesQ = [];
    for (const path of this.entitiesQ) {
      var _this$entityCount$get, _state$entitiesMeta$p, _state$entitiesMeta$p2;
      if (!((_this$entityCount$get = this.entityCount.get(path.key)) != null && _this$entityCount$get.has(path.pk)) && this.expiresAt((_state$entitiesMeta$p = (_state$entitiesMeta$p2 = state.entitiesMeta[path.key]) == null ? void 0 : _state$entitiesMeta$p2[path.pk]) != null ? _state$entitiesMeta$p : {
        fetchedAt: 0,
        date: 0,
        expiresAt: 0
      }) < now) {
        entities.push(path);
      } else {
        nextEntitiesQ.push(path);
      }
    }
    this.entitiesQ = nextEntitiesQ;
    if (entities.length || endpoints.length) {
      this.controller.dispatch({
        type: GC,
        entities,
        endpoints
      });
    }
  }

  /** Calls the callback when client is not 'busy' with high priority interaction tasks
   *
   * Override for platform-specific implementations
   */
  idleCallback(callback, options) {
    if (typeof requestIdleCallback === 'function') {
      requestIdleCallback(callback, options);
    } else {
      callback();
    }
  }
}
class ImmortalGCPolicy {
  // eslint-disable-next-line @typescript-eslint/no-empty-function
  init() {}
  // eslint-disable-next-line @typescript-eslint/no-empty-function
  cleanup() {}
  createCountRef() {
    return () => () => undefined;
  }
}

function selectMeta(state, fetchKey) {
  return state.meta[fetchKey];
}

const unsetDispatch = action => {
  throw new Error(`Dispatching while constructing your middleware is not allowed. ` + `Other middleware would not be applied to this dispatch.`);
};
const unsetState = () => {
  // This is only the value until it is set by the DataProvider
  /* istanbul ignore next */
  return initialState;
};

/**
 * Imperative control of Reactive Data Client store
 * @see https://dataclient.io/docs/api/Controller
 */
class Controller {
  /**
   * Dispatches an action to Reactive Data Client reducer.
   *
   * @see https://dataclient.io/docs/api/Controller#dispatch
   */

  /**
   * Gets the latest state snapshot that is fully committed.
   *
   * This can be useful for imperative use-cases like event handlers.
   * This should *not* be used to render; instead useSuspense() or useCache()
   * @see https://dataclient.io/docs/api/Controller#getState
   */

  /**
   * Singleton to maintain referential equality between calls
   */

  /**
   * Handles garbage collection
   */

  constructor({
    dispatch = unsetDispatch,
    getState = unsetState,
    memo = new normalizr.MemoCache(),
    gcPolicy = new ImmortalGCPolicy()
  } = {}) {
    this._dispatch = dispatch;
    this.getState = getState;
    this.memo = memo;
    this.gcPolicy = gcPolicy;
  }

  // TODO: drop when drop support for destructuring (0.14 and below)
  set dispatch(dispatch) {
    /* istanbul ignore next */
    this._dispatch = dispatch;
  }

  // TODO: drop when drop support for destructuring (0.14 and below)
  get dispatch() {
    return this._dispatch;
  }
  bindMiddleware({
    dispatch,
    getState
  }) {
    this._dispatch = dispatch;
    this.getState = getState;
  }

  /*************** Action Dispatchers ***************/

  /**
   * Fetches the endpoint with given args, updating the Reactive Data Client cache with the response or error upon completion.
   * @see https://dataclient.io/docs/api/Controller#fetch
   */
  fetch = (endpoint, ...args) => {
    const action = createFetch(endpoint, {
      args
    });
    this.dispatch(action);
    if (endpoint.schema) {
      return action.meta.promise.then(input => normalizr.denormalize(endpoint.schema, input, {}, args));
    }
    return action.meta.promise;
  };

  /**
   * Fetches only if endpoint is considered 'stale'; otherwise returns undefined
   * @see https://dataclient.io/docs/api/Controller#fetchIfStale
   */
  fetchIfStale = (endpoint, ...args) => {
    const {
      data,
      expiresAt,
      expiryStatus
    } = this.getResponseMeta(endpoint, ...args, this.getState());
    if (expiryStatus !== normalizr.ExpiryStatus.Invalid && Date.now() <= expiresAt) return data;
    return this.fetch(endpoint, ...args);
  };

  /**
   * Forces refetching and suspense on useSuspense with the same Endpoint and parameters.
   * @see https://dataclient.io/docs/api/Controller#invalidate
   */
  invalidate = (endpoint, ...args) => args[0] !== null ? this.dispatch(createInvalidate(endpoint, {
    args: args
  })) : Promise.resolve();

  /**
   * Forces refetching and suspense on useSuspense on all matching endpoint result keys.
   * @see https://dataclient.io/docs/api/Controller#invalidateAll
   * @returns Promise that resolves when invalidation is commited.
   */
  invalidateAll = options => this.dispatch(createInvalidateAll(key => options.testKey(key)));

  /**
   * Sets all matching endpoint result keys to be STALE.
   * @see https://dataclient.io/docs/api/Controller#expireAll
   * @returns Promise that resolves when expiry is commited. *NOT* fetch promise
   */
  expireAll = options => this.dispatch(createExpireAll(key => options.testKey(key)));

  /**
   * Resets the entire Reactive Data Client cache. All inflight requests will not resolve.
   * @see https://dataclient.io/docs/api/Controller#resetEntireStore
   */
  resetEntireStore = () => this.dispatch(createReset());

  /**
   * Sets value for the Queryable and args.
   * @see https://dataclient.io/docs/api/Controller#set
   */

  set(schema, ...rest) {
    const value = rest[rest.length - 1];
    const action = createSet(schema, {
      args: rest.slice(0, rest.length - 1),
      value
    });
    // TODO: reject with error if this fails in reducer
    return this.dispatch(action);
  }

  /**
   * Sets response for the Endpoint and args.
   * @see https://dataclient.io/docs/api/Controller#setResponse
   */
  setResponse = (endpoint, ...rest) => {
    const response = rest[rest.length - 1];
    const action = createSetResponse(endpoint, {
      args: rest.slice(0, rest.length - 1),
      response
    });
    return this.dispatch(action);
  };

  /**
   * Sets an error response for the Endpoint and args.
   * @see https://dataclient.io/docs/api/Controller#setError
   */
  setError = (endpoint, ...rest) => {
    const response = rest[rest.length - 1];
    const action = createSetResponse(endpoint, {
      args: rest.slice(0, rest.length - 1),
      response,
      error: true
    });
    return this.dispatch(action);
  };

  /**
   * Resolves an inflight fetch.
   * @see https://dataclient.io/docs/api/Controller#resolve
   */
  resolve = (endpoint, meta) => {
    return this.dispatch(createSetResponse(endpoint, meta));
  };

  /**
   * Marks a new subscription to a given Endpoint.
   * @see https://dataclient.io/docs/api/Controller#subscribe
   */
  subscribe = (endpoint, ...args) => args[0] !== null ? this.dispatch(createSubscription(endpoint, {
    args: args
  })) : Promise.resolve();

  /**
   * Marks completion of subscription to a given Endpoint.
   * @see https://dataclient.io/docs/api/Controller#unsubscribe
   */
  unsubscribe = (endpoint, ...args) => args[0] !== null ? this.dispatch(createUnsubscription(endpoint, {
    args: args
  })) : Promise.resolve();

  /*************** More ***************/

  /* TODO:
  abort = <E extends EndpointInterface>(
    endpoint: E,
    ...args: readonly [...Parameters<E>]
  ): Promise<void>
  */

  /**
   * Gets a snapshot (https://dataclient.io/docs/api/Snapshot)
   * @see https://dataclient.io/docs/api/Controller#snapshot
   */
  snapshot = (state, fetchedAt) => {
    return new Snapshot(this, state, fetchedAt);
  };

  /**
   * Gets the error, if any, for a given endpoint. Returns undefined for no errors.
   * @see https://dataclient.io/docs/api/Controller#getError
   */

  getError(endpoint, ...rest) {
    if (rest[0] === null) return;
    const state = rest[rest.length - 1];
    // this is typescript generics breaking
    const args = rest.slice(0, rest.length - 1);
    const key = endpoint.key(...args);
    const meta = selectMeta(state, key);
    const error = state.endpoints[key];
    if (error !== undefined && (meta == null ? void 0 : meta.errorPolicy) === 'soft') return;
    return meta == null ? void 0 : meta.error;
  }

  /**
   * Gets the (globally referentially stable) response for a given endpoint/args pair from state given.
   * @see https://dataclient.io/docs/api/Controller#getResponse
   */

  getResponse(endpoint, ...rest) {
    // TODO: breaking: only return data
    return this.getResponseMeta(endpoint, ...rest);
  }

  /**
   * Gets the (globally referentially stable) response for a given endpoint/args pair from state given.
   * @see https://dataclient.io/docs/api/Controller#getResponseMeta
   */

  getResponseMeta(endpoint, ...rest) {
    const [state, args] = extractStateAndArgs(rest);
    const isActive = args.length !== 1 || args[0] !== null;
    const key = isActive ? endpoint.key(...args) : '';
    const cacheEndpoints = isActive ? state.endpoints[key] : undefined;
    const schema = endpoint.schema;
    const meta = selectMeta(state, key);
    let expiresAt = meta == null ? void 0 : meta.expiresAt;
    // if we have no endpoint entry, and our endpoint has a schema - try querying the store
    const shouldQuery = cacheEndpoints === undefined && schema !== undefined;
    const input = shouldQuery ?
    // nothing in endpoints cache, so try querying if we have a schema to do so
    this.memo.buildQueryKey(schema, args, state, key) : cacheEndpoints;
    if (!isActive) {
      // when not active simply return the query input without denormalizing
      return {
        data: input,
        expiryStatus: normalizr.ExpiryStatus.Valid,
        expiresAt: Infinity,
        countRef: () => () => undefined
      };
    }
    let isInvalid = false;
    if (shouldQuery) {
      isInvalid = !normalizr.validateQueryKey(input);
      // endpoint without entities
    } else if (!schema || !requiresDenormalize(schema)) {
      return {
        data: cacheEndpoints,
        expiryStatus: this.getExpiryStatus(cacheEndpoints === undefined, !!endpoint.invalidIfStale, meta),
        expiresAt: expiresAt || 0,
        countRef: this.gcPolicy.createCountRef({
          key
        })
      };
    }
    const {
      data,
      paths
    } = this.memo.denormalize(schema, input, state.entities, args);
    if (!expiresAt) {
      // note: isInvalid can only be true if shouldQuery is true
      if (isInvalid) expiresAt = 1;
      // fallback to entity expiry time
      else expiresAt = entityExpiresAt(paths, state.entitiesMeta);
    }
    return {
      data,
      expiryStatus: this.getExpiryStatus(typeof data === 'symbol', !!endpoint.invalidIfStale || isInvalid, meta),
      expiresAt,
      countRef: this.gcPolicy.createCountRef({
        key,
        paths
      })
    };
  }

  /**
   * Queries the store for a Querable schema
   * @see https://dataclient.io/docs/api/Controller#get
   */
  get(schema, ...rest) {
    const [state, args] = extractStateAndArgs(rest);
    const {
      data
    } = this.memo.query(schema, args, state);
    return typeof data === 'symbol' ? undefined : data;
  }

  /**
   * Queries the store for a Querable schema; providing related metadata
   * @see https://dataclient.io/docs/api/Controller#getQueryMeta
   */
  getQueryMeta(schema, ...rest) {
    const [state, args] = extractStateAndArgs(rest);
    const {
      data,
      paths
    } = this.memo.query(schema, args, state);
    return {
      data: typeof data === 'symbol' ? undefined : data,
      countRef: this.gcPolicy.createCountRef({
        paths
      })
    };
  }
  getExpiryStatus(invalidData, invalidIfStale, meta = {}) {
    // https://dataclient.io/docs/concepts/expiry-policy#expiry-status
    // we don't track the difference between stale or fresh because that is tied to triggering
    // conditions
    return meta.invalidated || invalidData && !meta.error ? normalizr.ExpiryStatus.Invalid : invalidData || invalidIfStale ? normalizr.ExpiryStatus.InvalidIfStale : normalizr.ExpiryStatus.Valid;
  }
}

// benchmark: https://www.measurethat.net/Benchmarks/Show/24691/0/min-reducer-vs-imperative-with-paths
// earliest expiry dictates age
function entityExpiresAt(paths, entitiesMeta) {
  let expiresAt = Infinity;
  for (const {
    key,
    pk
  } of paths) {
    var _entitiesMeta$key;
    const entityExpiry = (_entitiesMeta$key = entitiesMeta[key]) == null || (_entitiesMeta$key = _entitiesMeta$key[pk]) == null ? void 0 : _entitiesMeta$key.expiresAt;
    // expiresAt will always resolve to false with any comparison
    if (entityExpiry < expiresAt) expiresAt = entityExpiry;
  }
  return expiresAt;
}

/** Whether `denormalize()` must run to reconstruct the response.
 *
 * True iff some node in the schema tree defines `normalize` — meaning it
 * transforms the response when written (entity write, polymorphic hoist,
 * lazy delegation, etc.), so the cached value differs from the response.
 * Mirrors the dispatch in `getVisit.ts`: schema classes are detected here
 * by the same hook the visit walker uses, so we never need to walk their
 * instance fields.
 */
function requiresDenormalize(schema) {
  if (!schema) return false;
  if (Array.isArray(schema)) return schema.length !== 0 && requiresDenormalize(schema[0]);
  // Must reject primitives before probing `.normalize` — `String.prototype.normalize` exists.
  const t = typeof schema;
  if (t !== 'object' && t !== 'function') return false;
  if (typeof schema.normalize === 'function') return true;
  // Plain-object schema map (e.g. `{ data: [Tacos], page: { ... } }`).
  return Object.values(schema).some(x => requiresDenormalize(x));
}
class Snapshot {
  static abort = new AbortOptimistic();
  state;
  controller;
  fetchedAt;
  abort = Snapshot.abort;
  constructor(controller, state, fetchedAt = 0) {
    this.state = state;
    this.controller = controller;
    this.fetchedAt = fetchedAt;
  }

  /*************** Data Access ***************/
  /** @see https://dataclient.io/docs/api/Snapshot#getResponse */

  getResponse(endpoint, ...args) {
    return this.controller.getResponse(endpoint, ...args, this.state);
  }

  /** @see https://dataclient.io/docs/api/Snapshot#getResponseMeta */

  getResponseMeta(endpoint, ...args) {
    return this.controller.getResponseMeta(endpoint, ...args, this.state);
  }

  /** @see https://dataclient.io/docs/api/Snapshot#getError */

  getError(endpoint, ...args) {
    return this.controller.getError(endpoint, ...args, this.state);
  }

  /**
   * Retrieved memoized value for any Querable schema
   * @see https://dataclient.io/docs/api/Snapshot#get
   */
  get(schema, ...args) {
    return this.controller.get(schema, ...args, this.state);
  }

  /**
   * Queries the store for a Querable schema; providing related metadata
   * @see https://dataclient.io/docs/api/Snapshot#getQueryMeta
   */
  getQueryMeta(schema, ...args) {
    return this.controller.getQueryMeta(schema, ...args, this.state);
  }
}

/** Extract state and args from rest params, applying ensurePojo to args */
function extractStateAndArgs(rest) {
  const l = rest.length;
  const args = new Array(l - 1);
  for (let i = 0; i < l - 1; i++) {
    // handle FormData
    args[i] = ensurePojo(rest[i]);
  }
  // this is typescript generics breaking
  return [rest[l - 1], args];
}

class ResetError extends Error {
  name = 'ResetError';
  constructor() {
    super('Aborted due to RESET');
  }
}
/** Handles all async network dispatches
 *
 * Dedupes concurrent requests by keeping track of all fetches in flight
 * and returning existing promises for requests already in flight.
 *
 * Interfaces with store via a redux-compatible middleware.
 *
 * @see https://dataclient.io/docs/api/NetworkManager
 */
class NetworkManager {
  fetching = new Map();
  controller = new Controller();
  constructor({
    dataExpiryLength = 60000,
    errorExpiryLength = 1000
  } = {}) {
    this.dataExpiryLength = dataExpiryLength;
    this.errorExpiryLength = errorExpiryLength;
  }
  middleware = controller => {
    this.controller = controller;
    return next => action => {
      switch (action.type) {
        case FETCH:
          this.handleFetch(action);
          // This is the only case that causes any state change
          // It's important to intercept other fetches as we don't want to trigger reducers during
          // render - so we need to stop 'readonly' fetches which can be triggered in render
          if (action.endpoint.getOptimisticResponse !== undefined && action.endpoint.sideEffect) {
            return next(action);
          }
          return Promise.resolve();
        case SET_RESPONSE:
          // only set after new state is computed
          return next(action).then(() => {
            if (this.fetching.has(action.key)) {
              var _controller$getState$;
              // Note: meta *must* be set by reducer so this should be safe
              const error = (_controller$getState$ = controller.getState().meta[action.key]) == null ? void 0 : _controller$getState$.error;
              // processing errors result in state meta having error, so we should reject the promise
              if (error) {
                this.handleSet(createSetResponse(action.endpoint, {
                  args: action.args,
                  response: error,
                  fetchedAt: action.meta.fetchedAt,
                  error: true
                }));
              } else {
                this.handleSet(action);
              }
            }
          });
        case RESET:
          {
            // take snapshot of rejectors at this point in time
            // we must use Array.from since iteration does not freeze state at this point in time
            const fetches = Array.from(this.fetching.values());
            this.clearAll();
            return next(action).then(() => {
              // there could be external listeners to the promise
              // this must happen after commit so our own rejector knows not to dispatch an error based on this
              for (const {
                reject
              } of fetches) {
                reject(new ResetError());
              }
            });
          }
        default:
          return next(action);
      }
    };
  };

  /** On mount */
  init() {
    delete this.cleanupDate;
  }

  /** Ensures all promises are completed by rejecting remaining. */
  cleanup() {
    // ensure no dispatches after unmount
    // this must be reversible (done in init) so useEffect() remains symmetric
    this.cleanupDate = Date.now();
  }

  /** Used by DevtoolsManager to determine whether to log an action */
  skipLogging(action) {
    /* istanbul ignore next */
    return action.type === FETCH && this.fetching.has(action.key);
  }
  allSettled() {
    if (this.fetching.size) return Promise.allSettled(this.fetching.values().map(({
      promise
    }) => promise));
  }

  /** Clear all promise state */
  clearAll() {
    for (const k of this.fetching.keys()) {
      this.clear(k);
    }
  }

  /** Clear promise state for a given key */
  clear(key) {
    if (this.fetching.has(key)) {
      this.fetching.get(key).promise.catch(() => {});
      this.fetching.delete(key);
    }
  }
  getLastReset() {
    if (this.cleanupDate) return this.cleanupDate;
    return this.controller.getState().lastReset;
  }

  /** Called when middleware intercepts 'rdc/fetch' action.
   *
   * Will then start a promise for a key and potentially start the network
   * fetch.
   *
   * Uses throttle endpoints without sideEffects. This is valuable
   * for ensures mutation requests always go through.
   */
  handleFetch(action) {
    const {
      resolve,
      reject,
      fetchedAt
    } = action.meta;
    const throttle = !action.endpoint.sideEffect;
    const deferedFetch = () => {
      let promise = action.endpoint(...action.args);
      const resolvePromise = promise => promise.then(data => {
        resolve(data);
        return data;
      }).catch(error => {
        reject(error);
        throw error;
      });
      // schedule non-throttled resolutions in a microtask before set
      // this enables users awaiting their fetch to trigger any react updates needed to deal
      // with upcoming changes because of the fetch (for instance avoiding suspense if something is deleted)
      if (!throttle) {
        promise = resolvePromise(promise);
      }
      promise = promise.then(response => {
        let lastReset = this.getLastReset();

        /* istanbul ignore else */
        if (process.env.NODE_ENV !== 'production' && isNaN(lastReset)) {
          console.error('state.lastReset is NaN. Only positive timestamps are valid.');
          lastReset = 0;
        }

        // don't update state with promises started before last clear
        if (fetchedAt >= lastReset) {
          this.controller.resolve(action.endpoint, {
            args: action.args,
            response,
            fetchedAt
          });
        }
        return response;
      }).catch(error => {
        const lastReset = this.getLastReset();
        // don't update state with promises started before last clear
        if (fetchedAt >= lastReset) {
          this.controller.resolve(action.endpoint, {
            args: action.args,
            response: error,
            fetchedAt,
            error: true
          });
        }
        throw error;
      });
      return promise;
    };
    if (throttle) {
      return this.throttle(action.key, deferedFetch, fetchedAt).then(data => resolve(data)).catch(error => reject(error));
    } else {
      return deferedFetch().catch(() => {});
    }
  }

  /** Called when middleware intercepts a set action.
   *
   * Will resolve the promise associated with set key.
   */
  handleSet(action) {
    // this can still turn out to be untrue since this is async
    if (this.fetching.has(action.key)) {
      const {
        reject,
        resolve
      } = this.fetching.get(action.key);
      if (action.error) {
        reject(action.response);
      } else {
        resolve(action.response);
      }

      // since we're resolved we no longer need to keep track of this promise
      this.clear(action.key);
    }
  }

  /** Ensures only one request for a given key is in flight at any time
   *
   * Uses key to either retrieve in-flight promise, or if not
   * create a new promise and call fetch.
   *
   * Note: The new promise is not actually tied to fetch at all,
   * but is resolved when the expected 'receive' action is processed.
   * This ensures promises are resolved only once their data is processed
   * by the reducer.
   */
  throttle(key, fetch, fetchedAt) {
    const lastReset = this.getLastReset();
    let fetchMeta = this.fetching.get(key);

    // we're already fetching so reuse the promise
    // fetches after reset do not count
    if (fetchMeta && fetchMeta.fetchedAt > lastReset) {
      return fetchMeta.promise;
    }
    fetchMeta = newFetchMeta(fetchedAt);
    this.fetching.set(key, fetchMeta);
    this.idleCallback(() => {
      // since our real promise is resolved via the wrapReducer(),
      // we should just stop all errors here.
      // TODO: decouple this from useFetcher() (that's what's dispatching the error the resolves in here)
      fetch().catch(() => null);
    }, {
      timeout: 500
    });
    return fetchMeta.promise;
  }

  /** Calls the callback when client is not 'busy' with high priority interaction tasks
   *
   * Override for platform-specific implementations
   */
  idleCallback(callback, options) {
    callback();
  }
}
function newFetchMeta(fetchedAt) {
  const fetchMeta = {
    fetchedAt
  };
  fetchMeta.promise = new Promise((resolve, reject) => {
    fetchMeta.resolve = resolve;
    fetchMeta.reject = reject;
  });
  return fetchMeta;
}

function applyManager(managers, controller) {
  /* istanbul ignore next */
  if (process.env.NODE_ENV !== 'production' && !managers.find(mgr => mgr instanceof NetworkManager)) {
    console.warn('NetworkManager not found; this is a required manager.');
    console.warn('See https://dataclient.io/docs/guides/redux for hooking up redux');
  }
  return managers.map((manager, i) => {
    if (!manager.middleware) manager.middleware = manager.getMiddleware == null ? void 0 : manager.getMiddleware();
    return api => {
      if (i === 0) {
        controller.bindMiddleware(api);
      }
      // controller is a superset of the middleware API
      return manager.middleware(controller);
    };
  });
}

/* These should be compatible with redux */

/* The next are types from React; but we don't want dependencies on it */

function initManager(managers, controller, initialState) {
  return () => {
    managers.forEach(manager => {
      manager.init == null || manager.init(initialState);
    });
    controller.gcPolicy.init(controller);
    return () => {
      managers.forEach(manager => {
        manager.cleanup();
      });
      controller.gcPolicy.cleanup();
    };
  };
}

class BrowserConnectionListener {
  isOnline() {
    if (navigator.onLine !== undefined) {
      return navigator.onLine;
    }
    return true;
  }
  addOnlineListener(handler) {
    addEventListener('online', handler);
  }
  removeOnlineListener(handler) {
    removeEventListener('online', handler);
  }
  addOfflineListener(handler) {
    addEventListener('offline', handler);
  }
  removeOfflineListener(handler) {
    removeEventListener('offline', handler);
  }
}
class AlwaysOnlineConnectionListener {
  isOnline() {
    /* istanbul ignore next */
    return true;
  }
  addOnlineListener() {}
  removeOnlineListener() {}
  addOfflineListener() {}
  removeOfflineListener() {}
}
let DefaultConnectionListener;
/* istanbul ignore if */
if (typeof navigator !== 'undefined' && typeof addEventListener === 'function') {
  DefaultConnectionListener = BrowserConnectionListener;
} else {
  /* istanbul ignore next */
  DefaultConnectionListener = AlwaysOnlineConnectionListener;
}
var DefaultConnectionListener$1 = DefaultConnectionListener;

/**
 * PollingSubscription keeps a given resource updated by
 * dispatching a fetch at a rate equal to the minimum update
 * interval requested.
 *
 * @see https://dataclient.io/docs/api/PollingSubscription
 */
class PollingSubscription {
  frequencyHistogram = new Map();
  constructor(action, controller, connectionListener) {
    if (action.endpoint.pollFrequency === undefined) throw new Error('frequency needed for polling subscription');
    this.endpoint = action.endpoint;
    this.frequency = action.endpoint.pollFrequency;
    this.args = action.args;
    this.key = action.key;
    this.frequencyHistogram.set(this.frequency, 1);
    this.controller = controller;
    this.connectionListener = connectionListener || new DefaultConnectionListener$1();

    // Kickstart running since this is initialized after the online notif is sent
    if (this.connectionListener.isOnline()) {
      this.onlineListener();
    } else {
      this.offlineListener();
    }
  }

  /** Subscribe to a frequency */
  add(frequency) {
    if (frequency === undefined) return;
    if (this.frequencyHistogram.has(frequency)) {
      this.frequencyHistogram.set(frequency, this.frequencyHistogram.get(frequency) + 1);
    } else {
      this.frequencyHistogram.set(frequency, 1);

      // new min so restart service
      if (frequency < this.frequency) {
        this.frequency = frequency;
        this.run();
      }
    }
  }

  /** Unsubscribe from a frequency */
  remove(frequency) {
    if (frequency === undefined) return false;
    if (this.frequencyHistogram.has(frequency)) {
      this.frequencyHistogram.set(frequency, this.frequencyHistogram.get(frequency) - 1);
      if (this.frequencyHistogram.get(frequency) < 1) {
        this.frequencyHistogram.delete(frequency);

        // nothing subscribed to this anymore...it is invalid
        if (this.frequencyHistogram.size === 0) {
          this.cleanup();
          return true;
        }

        // this was the min, so find the next size
        if (frequency <= this.frequency) {
          this.frequency = Math.min(...this.frequencyHistogram.keys());
          this.run();
        }
      }
    } /* istanbul ignore next */else if (process.env.NODE_ENV !== 'production') {
      console.error(`Mismatched remove: ${frequency} is not subscribed for ${this.key}`);
    }
    return false;
  }

  /** Cleanup means clearing out background interval. */
  cleanup() {
    if (this.intervalId) {
      clearInterval(this.intervalId);
      delete this.intervalId;
    }
    if (this.lastIntervalId) {
      clearInterval(this.lastIntervalId);
      delete this.lastIntervalId;
    }
    if (this.startId) {
      clearTimeout(this.startId);
      delete this.startId;
    }
    this.connectionListener.removeOnlineListener(this.onlineListener);
    this.connectionListener.removeOfflineListener(this.offlineListener);
  }

  /** Trigger request for latest resource */
  update() {
    const sup = this.endpoint;
    const endpoint = function (...args) {
      return sup.call(this, ...args);
    };
    Object.assign(endpoint, this.endpoint);
    endpoint.dataExpiryLength = this.frequency / 2;
    endpoint.errorExpiryLength = this.frequency / 10;
    endpoint.errorPolicy = () => 'soft';
    endpoint.key = () => this.key;
    // stop any errors here from bubbling
    this.controller.fetch(endpoint, ...this.args).catch(() => null);
  }

  /** What happens when browser goes offline */
  offlineListener = () => {
    // this clears existing listeners, so no need to clear offline listener
    this.cleanup();
    this.connectionListener.addOnlineListener(this.onlineListener);
  };

  /** What happens when browser comes online */
  onlineListener = () => {
    this.connectionListener.removeOnlineListener(this.onlineListener);
    const now = Date.now();
    this.startId = setTimeout(() => {
      if (this.startId) {
        delete this.startId;
        this.update();
        this.run();
      } else if (process.env.NODE_ENV !== 'production') {
        console.warn(`Poll setTimeout for ${this.key} still running, but timeoutId deleted`);
      }
    }, Math.max(0, this.lastFetchTime() - now + this.frequency));
    this.connectionListener.addOfflineListener(this.offlineListener);
  };

  /** Run polling process with current frequency
   *
   * Will clean up old poll interval on next run
   */
  run() {
    if (this.startId) return;
    if (this.intervalId) this.lastIntervalId = this.intervalId;
    this.intervalId = setInterval(() => {
      // since we don't know how long into the last poll it was before resetting
      // we wait til the next fetch to clear old intervals
      if (this.lastIntervalId) {
        clearInterval(this.lastIntervalId);
        delete this.lastIntervalId;
      }
      if (this.intervalId) this.update();else if (process.env.NODE_ENV !== 'production') {
        console.warn(`Poll intervalId for ${this.key} still running, but intervalId deleted`);
      }
    }, this.frequency);
  }

  /** Last fetch time */
  lastFetchTime() {
    var _this$controller$getS, _this$controller$getS2;
    return (_this$controller$getS = (_this$controller$getS2 = this.controller.getState().meta[this.key]) == null ? void 0 : _this$controller$getS2.date) != null ? _this$controller$getS : 0;
  }
}

/** Interface handling a single resource subscription */

/** The static class that constructs Subscription */

/** Handles subscription actions -> fetch or set actions
 *
 * Constructor takes a SubscriptionConstructable class to control how
 * subscriptions are handled. (e.g., polling, websockets)
 *
 * @see https://dataclient.io/docs/api/SubscriptionManager
 */
class SubscriptionManager {
  subscriptions = {};
  controller = new Controller();
  constructor(Subscription) {
    this.Subscription = Subscription;
  }
  middleware = controller => {
    this.controller = controller;
    return next => action => {
      switch (action.type) {
        case SUBSCRIBE:
          try {
            this.handleSubscribe(action);
          } catch (e) {
            console.error(e);
          }
          return Promise.resolve();
        case UNSUBSCRIBE:
          this.handleUnsubscribe(action);
          return Promise.resolve();
        default:
          return next(action);
      }
    };
  };

  /** Ensures all subscriptions are cleaned up. */
  cleanup() {
    for (const key in this.subscriptions) {
      this.subscriptions[key].cleanup();
    }
  }

  /** Called when middleware intercepts 'rdc/subscribe' action.
   *
   */
  handleSubscribe(action) {
    const key = action.key;
    if (key in this.subscriptions) {
      const frequency = action.endpoint.pollFrequency;
      this.subscriptions[key].add(frequency);
    } else {
      this.subscriptions[key] = new this.Subscription(action, this.controller);
    }
  }

  /** Called when middleware intercepts 'rdc/unsubscribe' action.
   *
   */
  handleUnsubscribe(action) {
    const key = action.key;

    /* istanbul ignore else */
    if (key in this.subscriptions) {
      const frequency = action.endpoint.pollFrequency;
      const empty = this.subscriptions[key].remove(frequency);
      if (empty) {
        delete this.subscriptions[key];
      }
    } else if (process.env.NODE_ENV !== 'production') {
      console.error(`Mismatched unsubscribe: ${key} is not subscribed`);
    }
  }
}

var _DevToolsManager;
let DEFAULT_CONFIG = {};
if (process.env.NODE_ENV !== 'production') {
  var _globalThis$document;
  const ex