jotai/index.cjs.js

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var react = require('react');
var useContextSelector = require('use-context-selector');

function _extends() {
  _extends = Object.assign || function (target) {
    for (var i = 1; i < arguments.length; i++) {
      var source = arguments[i];

      for (var key in source) {
        if (Object.prototype.hasOwnProperty.call(source, key)) {
          target[key] = source[key];
        }
      }
    }

    return target;
  };

  return _extends.apply(this, arguments);
}

var isSSR = typeof window === 'undefined' || /ServerSideRendering/.test(window.navigator && window.navigator.userAgent);
var useIsoLayoutEffect = isSSR ? function (fn) {
  return fn();
} : react.useLayoutEffect;

var appendMap = function appendMap(dst, src) {
  src.forEach(function (v, k) {
    dst.set(k, v);
  });
  return dst;
}; // create new map from two maps


var concatMap = function concatMap(src1, src2) {
  return appendMap(new Map(src1), src2);
}; // create new map and delete item


var deleteMapItem = function deleteMapItem(src, key) {
  var dst = new Map(src);
  dst.delete(key);
  return dst;
};

var warningObject = new Proxy({}, {
  get: function get() {
    throw new Error('Please use <Provider>');
  },
  apply: function apply() {
    throw new Error('Please use <Provider>');
  }
});

var addDependent = function addDependent(dependentsMap, atom, dependent) {
  var dependents = dependentsMap.get(atom);

  if (!dependents) {
    dependents = new Set();
    dependentsMap.set(atom, dependents);
  }

  dependents.add(dependent);
};

var deleteDependent = function deleteDependent(dependentsMap, dependent) {
  dependentsMap.forEach(function (dependents) {
    dependents.delete(dependent);
  });
};

var setDependencies = function setDependencies(dependentsMap, atom, dependencies) {
  deleteDependent(dependentsMap, atom);
  dependencies.forEach(function (dependency) {
    addDependent(dependentsMap, dependency, atom);
  });
};

var listDependents = function listDependents(dependentsMap, atom, excludeSelf) {
  var dependents = new Set(dependentsMap.get(atom));

  if (excludeSelf) {
    dependents.delete(atom);
  }

  return dependents;
};

var initialState = new Map();

var getAtomState = function getAtomState(atom, state, tmpState) {
  var atomState = tmpState && tmpState.get(atom) || state.get(atom);

  if (!atomState) {
    throw new Error('atom state not found. possibly a bug.');
  }

  return atomState;
};

var getAtomStateValue = function getAtomStateValue(atom, state, tmpState) {
  var atomState = tmpState && tmpState.get(atom) || state.get(atom);
  return atomState ? atomState.value : atom.init;
};

var readAtom = function readAtom(state, readingAtom, setState, dependentsMap, readPendingMap) {
  var readAtomValue = function readAtomValue(prevState, atom) {
    var partialState = new Map();
    var atomState = prevState.get(atom);

    if (atomState) {
      return [atomState, partialState];
    }

    var error = undefined;
    var promise = undefined;
    var value = null;
    var dependencies = new Set();
    var isSync = true;

    try {
      var promiseOrValue = atom.read(function (a) {
        if (dependencies) {
          dependencies.add(a);
        } else {
          addDependent(dependentsMap, a, atom);
        }

        if (a !== atom) {
          var _readAtomValue = readAtomValue(concatMap(prevState, partialState), a),
              _nextAtomState = _readAtomValue[0],
              nextPartialState = _readAtomValue[1];

          if (isSync) {
            appendMap(partialState, nextPartialState);
          } else {
            setState(function (prev) {
              return concatMap(prev, nextPartialState);
            });
          }

          if (_nextAtomState.readE) {
            throw _nextAtomState.readE;
          }

          if (_nextAtomState.readP) {
            throw _nextAtomState.readP;
          }

          return _nextAtomState.value;
        } // a === atom


        var aState = partialState.get(a) || prevState.get(a);

        if (aState) {
          if (aState.readP) {
            throw aState.readP;
          }

          return aState.value;
        }

        return a.init; // this should not be undefined
      });

      if (promiseOrValue instanceof Promise) {
        promise = promiseOrValue.then(function (value) {
          var _prev$get;

          setDependencies(dependentsMap, atom, dependencies);
          dependencies = null;
          var prev = readPendingMap.get(atom);

          if (prev && ((_prev$get = prev.get(atom)) == null ? void 0 : _prev$get.readP) === promise) {
            readPendingMap.set(atom, deleteMapItem(prev, atom));
          }

          setState(function (prev) {
            return new Map(prev).set(atom, {
              value: value
            });
          });
        }).catch(function (e) {
          var _prev$get2;

          var prev = readPendingMap.get(atom);

          if (prev && ((_prev$get2 = prev.get(atom)) == null ? void 0 : _prev$get2.readP) === promise) {
            readPendingMap.set(atom, deleteMapItem(prev, atom));
          }

          setState(function (prev) {
            return new Map(prev).set(atom, {
              value: getAtomStateValue(atom, prev),
              readE: e instanceof Error ? e : new Error(e)
            });
          });
        });
      } else {
        setDependencies(dependentsMap, atom, dependencies);
        dependencies = null;
        value = promiseOrValue;
      }
    } catch (errorOrPromise) {
      if (errorOrPromise instanceof Promise) {
        promise = errorOrPromise;
      } else if (errorOrPromise instanceof Error) {
        error = errorOrPromise;
      } else {
        error = new Error(errorOrPromise);
      }
    }

    var nextAtomState = {
      readE: error,
      readP: promise,
      value: promise ? atom.init : value
    };
    partialState.set(atom, nextAtomState);
    isSync = false;
    return [nextAtomState, partialState];
  };

  var prevPartialState = readPendingMap.get(readingAtom);

  var _readAtomValue2 = readAtomValue(prevPartialState ? concatMap(state, prevPartialState) : state, readingAtom),
      atomState = _readAtomValue2[0],
      partialState = _readAtomValue2[1];

  readPendingMap.set(readingAtom, prevPartialState ? concatMap(prevPartialState, partialState) : partialState);
  return atomState;
};

var addAtom = function addAtom(id, atom, setState, dependentsMap, readPendingMap) {
  addDependent(dependentsMap, atom, id);
  var partialState = readPendingMap.get(atom);

  if (partialState) {
    readPendingMap.delete(atom);
    setState(function (prev) {
      return concatMap(prev, partialState);
    });
  }
};

var delAtom = function delAtom(id, setGcCount, dependentsMap) {
  deleteDependent(dependentsMap, id);
  setGcCount(function (c) {
    return c + 1;
  }); // trigger re-render for gc
};

var gcAtom = function gcAtom(state, setState, dependentsMap) {
  var nextState = new Map(state);
  var deleted;

  do {
    deleted = false;
    nextState.forEach(function (_atomState, atom) {
      var _dependentsMap$get;

      var isEmpty = ((_dependentsMap$get = dependentsMap.get(atom)) == null ? void 0 : _dependentsMap$get.size) === 0;

      if (isEmpty) {
        nextState.delete(atom);
        dependentsMap.delete(atom);
        deleted = true;
      }
    });
  } while (deleted);

  if (nextState.size !== state.size) {
    setState(nextState);
  }
};

var writeAtom = function writeAtom(updatingAtom, update, setState, dependentsMap, addWriteThunk) {
  var pendingPromises = [];

  var updateDependentsState = function updateDependentsState(prevState, atom) {
    var partialState = new Map();
    listDependents(dependentsMap, atom, true).forEach(function (dependent) {
      if (typeof dependent === 'symbol') return;
      var dependencies = new Set();

      try {
        var promiseOrValue = dependent.read(function (a) {
          if (dependencies) {
            dependencies.add(a);
          } else {
            addDependent(dependentsMap, a, dependent);
          }

          var s = getAtomState(a, prevState);

          if (s.readE) {
            throw s.readE;
          }

          return s.value;
        });

        if (promiseOrValue instanceof Promise) {
          var promise = promiseOrValue.then(function (value) {
            setDependencies(dependentsMap, dependent, dependencies);
            dependencies = null;
            var nextAtomState = {
              value: value
            };
            setState(function (prev) {
              var _prev$get3;

              var prevPromise = (_prev$get3 = prev.get(dependent)) == null ? void 0 : _prev$get3.readP;

              if (prevPromise && prevPromise !== promise) {
                // There is a new promise, so we skip updating this one.
                return prev;
              }

              var nextState = new Map(prev).set(dependent, nextAtomState);
              var nextPartialState = updateDependentsState(nextState, dependent);
              return appendMap(nextState, nextPartialState);
            });
          }).catch(function (e) {
            setState(function (prev) {
              return new Map(prev).set(dependent, {
                value: getAtomStateValue(dependent, prev),
                readE: e instanceof Error ? e : new Error(e)
              });
            });
          });
          partialState.set(dependent, {
            value: getAtomStateValue(dependent, prevState),
            readP: promise
          });
        } else {
          setDependencies(dependentsMap, dependent, dependencies);
          dependencies = null;
          partialState.set(dependent, {
            value: promiseOrValue
          });
          appendMap(partialState, updateDependentsState(concatMap(prevState, partialState), dependent));
        }
      } catch (e) {
        partialState.set(dependent, {
          value: getAtomStateValue(dependent, prevState),
          readE: e instanceof Error ? e : new Error(e)
        });
        appendMap(partialState, updateDependentsState(concatMap(prevState, partialState), dependent));
      }
    });
    return partialState;
  };

  var updateAtomState = function updateAtomState(prevState, atom, update) {
    var prevAtomState = prevState.get(atom);

    if (prevAtomState && prevAtomState.writeP) {
      var promise = prevAtomState.writeP.then(function () {
        addWriteThunk(function (prev) {
          var nextPartialState = updateAtomState(prev, atom, update);

          if (nextPartialState) {
            return concatMap(prevState, nextPartialState);
          }

          return prev;
        });
      });
      pendingPromises.push(promise);
      return null;
    }

    var partialState = new Map();
    var isSync = true;

    try {
      var promiseOrVoid = atom.write(function (a) {
        if (process.env.NODE_ENV !== 'production') {
          var s = prevState.get(a);

          if (s && s.readP) {
            console.log('Reading pending atom state in write operation. Not sure how to deal with it. Returning stale vaule for', a);
          }
        }

        return getAtomStateValue(a, prevState, partialState);
      }, function (a, v) {
        if (a === atom) {
          var nextAtomState = {
            value: v
          };

          if (isSync) {
            partialState.set(a, nextAtomState);
            appendMap(partialState, updateDependentsState(concatMap(prevState, partialState), a));
          } else {
            setState(function (prev) {
              var nextState = new Map(prev).set(a, nextAtomState);
              var nextPartialState = updateDependentsState(nextState, a);
              return appendMap(nextState, nextPartialState);
            });
          }
        } else {
          if (isSync) {
            var nextPartialState = updateAtomState(concatMap(prevState, partialState), a, v);

            if (nextPartialState) {
              appendMap(partialState, nextPartialState);
            }
          } else {
            addWriteThunk(function (prev) {
              var nextPartialState = updateAtomState(prev, a, v);

              if (nextPartialState) {
                return concatMap(prev, nextPartialState);
              }

              return prev;
            });
          }
        }
      }, update);

      if (promiseOrVoid instanceof Promise) {
        pendingPromises.push(promiseOrVoid);

        var nextAtomState = _extends({}, getAtomState(atom, prevState, partialState), {
          writeP: promiseOrVoid.then(function () {
            addWriteThunk(function (prev) {
              return new Map(prev).set(atom, _extends({}, getAtomState(atom, prev), {
                writeP: undefined
              }));
            });
          })
        });

        partialState.set(atom, nextAtomState);
      }
    } catch (e) {
      if (pendingPromises.length) {
        pendingPromises.push(new Promise(function (_resolve, reject) {
          reject(e);
        }));
      } else {
        throw e;
      }
    }

    isSync = false;
    return partialState;
  };

  addWriteThunk(function (prevState) {
    var nextPartialState = updateAtomState(prevState, updatingAtom, update);

    if (nextPartialState) {
      return concatMap(prevState, nextPartialState);
    }

    return prevState;
  });

  if (pendingPromises.length) {
    return new Promise(function (resolve, reject) {
      var loop = function loop() {
        var len = pendingPromises.length;

        if (len === 0) {
          resolve();
        } else {
          Promise.all(pendingPromises).then(function () {
            pendingPromises.splice(0, len);
            loop();
          }).catch(reject);
        }
      };

      loop();
    });
  }
};

var runWriteThunk = function runWriteThunk(lastStateRef, setState, writeThunkQueue) {
  while (true) {
    if (!lastStateRef.current) {
      return;
    }

    if (writeThunkQueue.length === 0) {
      return;
    }

    var thunk = writeThunkQueue.shift();
    var lastState = lastStateRef.current;
    var nextState = thunk(lastState);

    if (nextState !== lastState) {
      setState(nextState);
      return;
    }
  }
};

var ActionsContext = useContextSelector.createContext(warningObject);
var StateContext = useContextSelector.createContext(warningObject);
var Provider = function Provider(_ref) {
  var children = _ref.children;
  var dependentsMapRef = react.useRef();

  if (!dependentsMapRef.current) {
    dependentsMapRef.current = new Map();
  }

  var readPendingMapRef = react.useRef();

  if (!readPendingMapRef.current) {
    readPendingMapRef.current = new WeakMap();
  }

  var _useState = react.useState(initialState),
      state = _useState[0],
      setStateOrig = _useState[1];

  var lastStateRef = react.useRef(null);

  var setState = function setState(setStateAction) {
    lastStateRef.current = null;
    setStateOrig(setStateAction);
  };

  useIsoLayoutEffect(function () {
    if (state !== initialState) {
      lastStateRef.current = state;
    }
  });

  var _useState2 = react.useState(0),
      gcCount = _useState2[0],
      setGcCount = _useState2[1]; // to trigger gc


  react.useEffect(function () {
    gcAtom(state, setState, dependentsMapRef.current);
  }, [state, gcCount]);
  var writeThunkQueueRef = react.useRef([]);
  react.useEffect(function () {
    runWriteThunk(lastStateRef, setState, writeThunkQueueRef.current);
  }, [state]);
  var actions = react.useMemo(function () {
    return {
      add: function add(id, atom) {
        return addAtom(id, atom, setState, dependentsMapRef.current, readPendingMapRef.current);
      },
      del: function del(id) {
        return delAtom(id, setGcCount, dependentsMapRef.current);
      },
      read: function read(state, atom) {
        return readAtom(state, atom, setState, dependentsMapRef.current, readPendingMapRef.current);
      },
      write: function write(atom, update) {
        return writeAtom(atom, update, setState, dependentsMapRef.current, function (thunk) {
          writeThunkQueueRef.current.push(thunk);
          runWriteThunk(lastStateRef, setState, writeThunkQueueRef.current);
        });
      }
    };
  }, []);
  return react.createElement(ActionsContext.Provider, {
    value: actions
  }, react.createElement(StateContext.Provider, {
    value: state
  }, children));
};

var keyCount = 0; // global key count for all atoms

function atom(read, write) {
  var config = {
    key: ++keyCount
  };

  if (typeof read === 'function') {
    config.read = read;
  } else {
    config.init = read;

    config.read = function (get) {
      return get(config);
    };

    config.write = function (get, set, update) {
      set(config, typeof update === 'function' ? update(get(config)) : update);
    };
  }

  if (write) {
    config.write = write;
  }

  return config;
}

var isWritable = function isWritable(atom) {
  return !!atom.write;
};

function useAtom(atom) {
  var actions = useContextSelector.useContext(ActionsContext);
  var value = useContextSelector.useContextSelector(StateContext, react.useCallback(function (state) {
    var atomState = actions.read(state, atom);

    if (atomState.readE) {
      throw atomState.readE; // read error
    }

    if (atomState.readP) {
      throw atomState.readP; // read promise
    }

    if (atomState.writeP) {
      throw atomState.writeP; // write promise
    }

    return atomState.value;
  }, [atom, actions]));
  useIsoLayoutEffect(function () {
    var id = Symbol();
    actions.add(id, atom);
    return function () {
      actions.del(id);
    };
  }, [actions, atom]);
  var setAtom = react.useCallback(function (update) {
    if (isWritable(atom)) {
      return actions.write(atom, update);
    } else {
      throw new Error('not writable atom');
    }
  }, [atom, actions]);
  react.useDebugValue(value);
  return [value, setAtom];
}

var useBridge = function useBridge() {
  var actions = useContextSelector.useContext(ActionsContext);
  var state = useContextSelector.useContext(StateContext);
  return react.useMemo(function () {
    return [actions, state];
  }, [actions, state]);
};
var Bridge = function Bridge(_ref) {
  var value = _ref.value,
      children = _ref.children;
  var actions = value[0],
      state = value[1];
  return react.createElement(useContextSelector.BridgeProvider, {
    context: ActionsContext,
    value: actions
  }, react.createElement(useContextSelector.BridgeProvider, {
    context: StateContext,
    value: state
  }, children));
};

exports.Bridge = Bridge;
exports.Provider = Provider;
exports.atom = atom;
exports.useAtom = useAtom;
exports.useBridge = useBridge;