immer-peasy/dist/immer.module.js

Easy Peasy friendly modification of immer

var obj;
var NOTHING = typeof Symbol !== "undefined" ? Symbol("immer-nothing") : ( obj = {}, obj["immer-nothing"] = true, obj );
var DRAFTABLE = typeof Symbol !== "undefined" && Symbol.for ? Symbol.for("immer-draftable") : "__$immer_draftable";
var DRAFT_STATE = typeof Symbol !== "undefined" && Symbol.for ? Symbol.for("immer-state") : "__$immer_state";
function isDraft(value) {
  return !!value && !!value[DRAFT_STATE];
}
function isDraftable(value) {
  if (!value || typeof value !== "object") { return false; }
  if (Array.isArray(value)) { return true; }
  var proto = Object.getPrototypeOf(value);
  if (!proto || proto === Object.prototype) { return true; }
  return !!value[DRAFTABLE] || !!value.constructor[DRAFTABLE];
}
function original(value) {
  if (value && value[DRAFT_STATE]) {
    return value[DRAFT_STATE].base;
  } // otherwise return undefined

}
var assign = Object.assign || function assign(target, value) {
  for (var key in value) {
    if (has(value, key)) {
      target[key] = value[key];
    }
  }

  return target;
};
var ownKeys = typeof Reflect !== "undefined" && Reflect.ownKeys ? Reflect.ownKeys : typeof Object.getOwnPropertySymbols !== "undefined" ? function (obj) { return Object.getOwnPropertyNames(obj).concat(Object.getOwnPropertySymbols(obj)); } : Object.getOwnPropertyNames;
function shallowCopy(base, invokeGetters) {
  if ( invokeGetters === void 0 ) invokeGetters = false;

  if (Array.isArray(base)) { return base.slice(); }
  var clone = Object.create(Object.getPrototypeOf(base));
  ownKeys(base).forEach(function (key) {
    if (key === DRAFT_STATE) {
      return; // Never copy over draft state.
    }

    var desc = Object.getOwnPropertyDescriptor(base, key);
    var value = desc.value;

    if (desc.get) {
      if (invokeGetters) {
        value = desc.get.call(base);
      }
    }

    if (desc.enumerable) {
      clone[key] = value;
    } else if (invokeGetters) {
      Object.defineProperty(clone, key, {
        value: value,
        writable: true,
        configurable: true
      });
    }
  });
  return clone;
}
function each(value, cb) {
  if (Array.isArray(value)) {
    for (var i = 0; i < value.length; i++) { cb(i, value[i], value); }
  } else {
    ownKeys(value).forEach(function (key) { return cb(key, value[key], value); });
  }
}
function isEnumerable(base, prop) {
  var desc = Object.getOwnPropertyDescriptor(base, prop);
  return !!desc && desc.enumerable;
}
function has(thing, prop) {
  return Object.prototype.hasOwnProperty.call(thing, prop);
}
function is(x, y) {
  // From: https://github.com/facebook/fbjs/blob/c69904a511b900266935168223063dd8772dfc40/packages/fbjs/src/core/shallowEqual.js
  if (x === y) {
    return x !== 0 || 1 / x === 1 / y;
  } else {
    return x !== x && y !== y;
  }
}

/** Each scope represents a `produce` call. */

var ImmerScope = function ImmerScope(parent) {
  this.drafts = [];
  this.parent = parent; // Whenever the modified draft contains a draft from another scope, we
  // need to prevent auto-freezing so the unowned draft can be finalized.

  this.canAutoFreeze = true; // To avoid prototype lookups:

  this.patches = null;
};

ImmerScope.prototype.usePatches = function usePatches (patchListener) {
  if (patchListener) {
    this.patches = [];
    this.inversePatches = [];
    this.patchListener = patchListener;
  }
};

ImmerScope.prototype.revoke = function revoke$1 () {
  this.leave();
  this.drafts.forEach(revoke);
  this.drafts = null; // Make draft-related methods throw.
};

ImmerScope.prototype.leave = function leave () {
  if (this === ImmerScope.current) {
    ImmerScope.current = this.parent;
  }
};
ImmerScope.current = null;

ImmerScope.enter = function () {
  return this.current = new ImmerScope(this.current);
};

function revoke(draft) {
  draft[DRAFT_STATE].revoke();
}

// but share them all instead

var descriptors = {};
function willFinalize(scope, result, isReplaced) {
  scope.drafts.forEach(function (draft) {
    draft[DRAFT_STATE].finalizing = true;
  });

  if (!isReplaced) {
    if (scope.patches) {
      markChangesRecursively(scope.drafts[0]);
    } // This is faster when we don't care about which attributes changed.


    markChangesSweep(scope.drafts);
  } // When a child draft is returned, look for changes.
  else if (isDraft(result) && result[DRAFT_STATE].scope === scope) {
      markChangesSweep(scope.drafts);
    }
}
function createProxy(base, parent) {
  var isArray = Array.isArray(base);
  var draft = clonePotentialDraft(base);
  each(draft, function (prop) {
    proxyProperty(draft, prop, isArray || isEnumerable(base, prop));
  }); // See "proxy.js" for property documentation.

  var scope = parent ? parent.scope : ImmerScope.current;
  var state = {
    scope: scope,
    modified: false,
    finalizing: false,
    // es5 only
    finalized: false,
    assigned: {},
    parent: parent,
    base: base,
    draft: draft,
    copy: null,
    revoke: revoke$1,
    revoked: false // es5 only

  };
  createHiddenProperty(draft, DRAFT_STATE, state);
  scope.drafts.push(draft);
  return draft;
}

function revoke$1() {
  this.revoked = true;
}

function source(state) {
  return state.copy || state.base;
} // Access a property without creating an Immer draft.


function peek(draft, prop) {
  var state = draft[DRAFT_STATE];

  if (state && !state.finalizing) {
    state.finalizing = true;
    var value = draft[prop];
    state.finalizing = false;
    return value;
  }

  return draft[prop];
}

function get(state, prop) {
  assertUnrevoked(state);
  var value = peek(source(state), prop);
  if (state.finalizing) { return value; } // Create a draft if the value is unmodified.

  if (value === peek(state.base, prop) && isDraftable(value)) {
    prepareCopy(state);
    return state.copy[prop] = createProxy(value, state);
  }

  return value;
}

function set(state, prop, value) {
  assertUnrevoked(state);
  state.assigned[prop] = true;

  if (!state.modified) {
    if (is(value, peek(source(state), prop))) { return; }
    markChanged(state);
    prepareCopy(state);
  }

  state.copy[prop] = value;
}

function markChanged(state) {
  if (!state.modified) {
    state.modified = true;
    if (state.parent) { markChanged(state.parent); }
  }
}

function prepareCopy(state) {
  if (!state.copy) { state.copy = clonePotentialDraft(state.base); }
}

function clonePotentialDraft(base) {
  var state = base && base[DRAFT_STATE];

  if (state) {
    state.finalizing = true;
    var draft = shallowCopy(state.draft, true);
    state.finalizing = false;
    return draft;
  }

  return shallowCopy(base);
}

function proxyProperty(draft, prop, enumerable) {
  var desc = descriptors[prop];

  if (desc) {
    desc.enumerable = enumerable;
  } else {
    descriptors[prop] = desc = {
      configurable: true,
      enumerable: enumerable,

      get: function get$1() {
        return get(this[DRAFT_STATE], prop);
      },

      set: function set$1(value) {
        set(this[DRAFT_STATE], prop, value);
      }

    };
  }

  Object.defineProperty(draft, prop, desc);
}

function assertUnrevoked(state) {
  if (state.revoked === true) { throw new Error("Cannot use a proxy that has been revoked. Did you pass an object from inside an immer function to an async process? " + JSON.stringify(source(state))); }
} // This looks expensive, but only proxies are visited, and only objects without known changes are scanned.


function markChangesSweep(drafts) {
  // The natural order of drafts in the `scope` array is based on when they
  // were accessed. By processing drafts in reverse natural order, we have a
  // better chance of processing leaf nodes first. When a leaf node is known to
  // have changed, we can avoid any traversal of its ancestor nodes.
  for (var i = drafts.length - 1; i >= 0; i--) {
    var state = drafts[i][DRAFT_STATE];

    if (!state.modified) {
      if (Array.isArray(state.base)) {
        if (hasArrayChanges(state)) { markChanged(state); }
      } else if (hasObjectChanges(state)) { markChanged(state); }
    }
  }
}

function markChangesRecursively(object) {
  if (!object || typeof object !== "object") { return; }
  var state = object[DRAFT_STATE];
  if (!state) { return; }
  var base = state.base;
  var draft = state.draft;
  var assigned = state.assigned;

  if (!Array.isArray(object)) {
    // Look for added keys.
    Object.keys(draft).forEach(function (key) {
      // The `undefined` check is a fast path for pre-existing keys.
      if (base[key] === undefined && !has(base, key)) {
        assigned[key] = true;
        markChanged(state);
      } else if (!assigned[key]) {
        // Only untouched properties trigger recursion.
        markChangesRecursively(draft[key]);
      }
    }); // Look for removed keys.

    Object.keys(base).forEach(function (key) {
      // The `undefined` check is a fast path for pre-existing keys.
      if (draft[key] === undefined && !has(draft, key)) {
        assigned[key] = false;
        markChanged(state);
      }
    });
  } else if (hasArrayChanges(state)) {
    markChanged(state);
    assigned.length = true;

    if (draft.length < base.length) {
      for (var i = draft.length; i < base.length; i++) { assigned[i] = false; }
    } else {
      for (var i$1 = base.length; i$1 < draft.length; i$1++) { assigned[i$1] = true; }
    }

    for (var i$2 = 0; i$2 < draft.length; i$2++) {
      // Only untouched indices trigger recursion.
      if (assigned[i$2] === undefined) { markChangesRecursively(draft[i$2]); }
    }
  }
}

function hasObjectChanges(state) {
  var base = state.base;
  var draft = state.draft; // Search for added keys and changed keys. Start at the back, because
  // non-numeric keys are ordered by time of definition on the object.

  var keys = Object.keys(draft);

  for (var i = keys.length - 1; i >= 0; i--) {
    var key = keys[i];
    var baseValue = base[key]; // The `undefined` check is a fast path for pre-existing keys.

    if (baseValue === undefined && !has(base, key)) {
      return true;
    } // Once a base key is deleted, future changes go undetected, because its
    // descriptor is erased. This branch detects any missed changes.
    else {
        var value = draft[key];
        var state$1 = value && value[DRAFT_STATE];

        if (state$1 ? state$1.base !== baseValue : !is(value, baseValue)) {
          return true;
        }
      }
  } // At this point, no keys were added or changed.
  // Compare key count to determine if keys were deleted.


  return keys.length !== Object.keys(base).length;
}

function hasArrayChanges(state) {
  var draft = state.draft;
  if (draft.length !== state.base.length) { return true; } // See #116
  // If we first shorten the length, our array interceptors will be removed.
  // If after that new items are added, result in the same original length,
  // those last items will have no intercepting property.
  // So if there is no own descriptor on the last position, we know that items were removed and added
  // N.B.: splice, unshift, etc only shift values around, but not prop descriptors, so we only have to check
  // the last one

  var descriptor = Object.getOwnPropertyDescriptor(draft, draft.length - 1); // descriptor can be null, but only for newly created sparse arrays, eg. new Array(10)

  if (descriptor && !descriptor.get) { return true; } // For all other cases, we don't have to compare, as they would have been picked up by the index setters

  return false;
}

function createHiddenProperty(target, prop, value) {
  Object.defineProperty(target, prop, {
    value: value,
    enumerable: false,
    writable: true
  });
}

var legacyProxy = /*#__PURE__*/Object.freeze({
    willFinalize: willFinalize,
    createProxy: createProxy
});

function willFinalize$1() {}
function createProxy$1(base, parent) {
  var scope = parent ? parent.scope : ImmerScope.current;
  var state = {
    // Track which produce call this is associated with.
    scope: scope,
    // True for both shallow and deep changes.
    modified: false,
    // Used during finalization.
    finalized: false,
    // Track which properties have been assigned (true) or deleted (false).
    assigned: {},
    // The parent draft state.
    parent: parent,
    // The base state.
    base: base,
    // The base proxy.
    draft: null,
    // Any property proxies.
    drafts: {},
    // The base copy with any updated values.
    copy: null,
    // Called by the `produce` function.
    revoke: null
  };
  var ref = Array.isArray(base) ? // [state] is used for arrays, to make sure the proxy is array-ish and not violate invariants,
  // although state itself is an object
  Proxy.revocable([state], arrayTraps) : Proxy.revocable(state, objectTraps);
  var revoke = ref.revoke;
  var proxy = ref.proxy;
  state.draft = proxy;
  state.revoke = revoke;
  scope.drafts.push(proxy);
  return proxy;
}
var objectTraps = {
  get: get$1,

  has: function has(target, prop) {
    return prop in source$1(target);
  },

  ownKeys: function ownKeys(target) {
    return Reflect.ownKeys(source$1(target));
  },

  set: set$1,
  deleteProperty: deleteProperty,
  getOwnPropertyDescriptor: getOwnPropertyDescriptor,

  defineProperty: function defineProperty() {
    throw new Error("Object.defineProperty() cannot be used on an Immer draft"); // prettier-ignore
  },

  getPrototypeOf: function getPrototypeOf(target) {
    return Object.getPrototypeOf(target.base);
  },

  setPrototypeOf: function setPrototypeOf() {
    throw new Error("Object.setPrototypeOf() cannot be used on an Immer draft"); // prettier-ignore
  }

};
var arrayTraps = {};
each(objectTraps, function (key, fn) {
  arrayTraps[key] = function () {
    arguments[0] = arguments[0][0];
    return fn.apply(this, arguments);
  };
});

arrayTraps.deleteProperty = function (state, prop) {
  if (isNaN(parseInt(prop))) {
    throw new Error("Immer only supports deleting array indices"); // prettier-ignore
  }

  return objectTraps.deleteProperty.call(this, state[0], prop);
};

arrayTraps.set = function (state, prop, value) {
  if (prop !== "length" && isNaN(parseInt(prop))) {
    throw new Error("Immer only supports setting array indices and the 'length' property"); // prettier-ignore
  }

  return objectTraps.set.call(this, state[0], prop, value);
}; // returns the object we should be reading the current value from, which is base, until some change has been made


function source$1(state) {
  return state.copy || state.base;
} // Access a property without creating an Immer draft.


function peek$1(draft, prop) {
  var state = draft[DRAFT_STATE];
  var desc = Reflect.getOwnPropertyDescriptor(state ? source$1(state) : draft, prop);
  return desc && desc.value;
}

function get$1(state, prop) {
  if (prop === DRAFT_STATE) { return state; }
  var drafts = state.drafts; // Check for existing draft in unmodified state.

  if (!state.modified && has(drafts, prop)) {
    return drafts[prop];
  }

  var value = source$1(state)[prop];

  if (state.finalized || !isDraftable(value)) {
    return value;
  } // Check for existing draft in modified state.


  if (state.modified) {
    // Assigned values are never drafted. This catches any drafts we created, too.
    if (value !== peek$1(state.base, prop)) { return value; } // Store drafts on the copy (when one exists).

    drafts = state.copy;
  }

  return drafts[prop] = createProxy$1(value, state);
}

function set$1(state, prop, value) {
  if (!state.modified) {
    var baseValue = peek$1(state.base, prop); // Optimize based on value's truthiness. Truthy values are guaranteed to
    // never be undefined, so we can avoid the `in` operator. Lastly, truthy
    // values may be drafts, but falsy values are never drafts.

    var isUnchanged = value ? is(baseValue, value) || value === state.drafts[prop] : is(baseValue, value) && prop in state.base;
    if (isUnchanged) { return true; }
    markChanged$1(state);
  }

  state.assigned[prop] = true;
  state.copy[prop] = value;
  return true;
}

function deleteProperty(state, prop) {
  // The `undefined` check is a fast path for pre-existing keys.
  if (peek$1(state.base, prop) !== undefined || prop in state.base) {
    state.assigned[prop] = false;
    markChanged$1(state);
  }

  if (state.copy) { delete state.copy[prop]; }
  return true;
} // Note: We never coerce `desc.value` into an Immer draft, because we can't make
// the same guarantee in ES5 mode.


function getOwnPropertyDescriptor(state, prop) {
  var owner = source$1(state);
  var desc = Reflect.getOwnPropertyDescriptor(owner, prop);

  if (desc) {
    desc.writable = true;
    desc.configurable = !Array.isArray(owner) || prop !== "length";
  }

  return desc;
}

function markChanged$1(state) {
  if (!state.modified) {
    state.modified = true;
    state.copy = assign(shallowCopy(state.base), state.drafts);
    state.drafts = null;
    if (state.parent) { markChanged$1(state.parent); }
  }
}

var modernProxy = /*#__PURE__*/Object.freeze({
    willFinalize: willFinalize$1,
    createProxy: createProxy$1
});

function generatePatches(state, basePath, patches, inversePatches) {
  Array.isArray(state.base) ? generateArrayPatches(state, basePath, patches, inversePatches) : generateObjectPatches(state, basePath, patches, inversePatches);
}

function generateArrayPatches(state, basePath, patches, inversePatches) {
  var assign, assign$1;

  var base = state.base;
  var copy = state.copy;
  var assigned = state.assigned; // Reduce complexity by ensuring `base` is never longer.

  if (copy.length < base.length) {
    (assign = [copy, base], base = assign[0], copy = assign[1]);
    (assign$1 = [inversePatches, patches], patches = assign$1[0], inversePatches = assign$1[1]);
  }

  var delta = copy.length - base.length; // Find the first replaced index.

  var start = 0;

  while (base[start] === copy[start] && start < base.length) {
    ++start;
  } // Find the last replaced index. Search from the end to optimize splice patches.


  var end = base.length;

  while (end > start && base[end - 1] === copy[end + delta - 1]) {
    --end;
  } // Process replaced indices.


  for (var i = start; i < end; ++i) {
    if (assigned[i] && copy[i] !== base[i]) {
      var path = basePath.concat([i]);
      patches.push({
        op: "replace",
        path: path,
        value: copy[i]
      });
      inversePatches.push({
        op: "replace",
        path: path,
        value: base[i]
      });
    }
  }

  var useRemove = end != base.length;
  var replaceCount = patches.length; // Process added indices.

  for (var i$1 = end + delta - 1; i$1 >= end; --i$1) {
    var path$1 = basePath.concat([i$1]);
    patches[replaceCount + i$1 - end] = {
      op: "add",
      path: path$1,
      value: copy[i$1]
    };

    if (useRemove) {
      inversePatches.push({
        op: "remove",
        path: path$1
      });
    }
  } // One "replace" patch reverses all non-splicing "add" patches.


  if (!useRemove) {
    inversePatches.push({
      op: "replace",
      path: basePath.concat(["length"]),
      value: base.length
    });
  }
}

function generateObjectPatches(state, basePath, patches, inversePatches) {
  var base = state.base;
  var copy = state.copy;
  each(state.assigned, function (key, assignedValue) {
    var origValue = base[key];
    var value = copy[key];
    var op = !assignedValue ? "remove" : key in base ? "replace" : "add";
    if (origValue === value && op === "replace") { return; }
    var path = basePath.concat(key);
    patches.push(op === "remove" ? {
      op: op,
      path: path
    } : {
      op: op,
      path: path,
      value: value
    });
    inversePatches.push(op === "add" ? {
      op: "remove",
      path: path
    } : op === "remove" ? {
      op: "add",
      path: path,
      value: origValue
    } : {
      op: "replace",
      path: path,
      value: origValue
    });
  });
}

function applyPatches(draft, patches) {
  for (var i = 0; i < patches.length; i++) {
    var patch = patches[i];
    var path = patch.path;

    if (path.length === 0 && patch.op === "replace") {
      draft = patch.value;
    } else {
      var base = draft;

      for (var i$1 = 0; i$1 < path.length - 1; i$1++) {
        base = base[path[i$1]];
        if (!base || typeof base !== "object") { throw new Error("Cannot apply patch, path doesn't resolve: " + path.join("/")); } // prettier-ignore
      }

      var key = path[path.length - 1];

      switch (patch.op) {
        case "replace":
          base[key] = patch.value;
          break;

        case "add":
          if (Array.isArray(base)) {
            // TODO: support "foo/-" paths for appending to an array
            base.splice(key, 0, patch.value);
          } else {
            base[key] = patch.value;
          }

          break;

        case "remove":
          if (Array.isArray(base)) {
            base.splice(key, 1);
          } else {
            delete base[key];
          }

          break;

        default:
          throw new Error("Unsupported patch operation: " + patch.op);
      }
    }
  }

  return draft;
}

function verifyMinified() {}

var configDefaults = {
  useProxies: typeof Proxy !== "undefined" && typeof Reflect !== "undefined",
  autoFreeze: typeof process !== "undefined" ? process.env.NODE_ENV !== "production" : verifyMinified.name === "verifyMinified",
  onAssign: null,
  onDelete: null,
  onCopy: null
};
var Immer = function Immer(config) {
  assign(this, configDefaults, config);
  this.setUseProxies(this.useProxies);
  this.produce = this.produce.bind(this);
};

Immer.prototype.produce = function produce (base, recipe, patchListener) {
    var this$1 = this;

  // curried invocation
  if (typeof base === "function" && typeof recipe !== "function") {
    var defaultBase = recipe;
    recipe = base;
    var self = this;
    return function curriedProduce(base) {
        var this$1 = this;
        if ( base === void 0 ) base = defaultBase;
        var args = [], len = arguments.length - 1;
        while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];

      return self.produce(base, function (draft) { return recipe.call.apply(recipe, [ this$1, draft ].concat( args )); }); // prettier-ignore
    };
  } // prettier-ignore


  {
    if (typeof recipe !== "function") {
      throw new Error("The first or second argument to `produce` must be a function");
    }

    if (patchListener !== undefined && typeof patchListener !== "function") {
      throw new Error("The third argument to `produce` must be a function or undefined");
    }
  }
  var result; // Only plain objects, arrays, and "immerable classes" are drafted.

  if (isDraftable(base)) {
    var scope = ImmerScope.enter();
    var proxy = this.createProxy(base);
    var hasError = true;

    try {
      result = recipe(proxy);
      hasError = false;
    } finally {
      // finally instead of catch + rethrow better preserves original stack
      if (hasError) { scope.revoke(); }else { scope.leave(); }
    }

    if (result instanceof Promise) {
      return result.then(function (result) {
        scope.usePatches(patchListener);
        return this$1.processResult(result, scope);
      }, function (error) {
        scope.revoke();
        throw error;
      });
    }

    scope.usePatches(patchListener);
    return this.processResult(result, scope);
  } else {
    result = recipe(base);
    if (result === undefined) { return base; }
    return result !== NOTHING ? result : undefined;
  }
};

Immer.prototype.createDraft = function createDraft (base) {
  if (!isDraftable(base)) {
    throw new Error("First argument to `createDraft` must be a plain object, an array, or an immerable object"); // prettier-ignore
  }

  var scope = ImmerScope.enter();
  var proxy = this.createProxy(base);
  proxy[DRAFT_STATE].isManual = true;
  scope.leave();
  return proxy;
};

Immer.prototype.finishDraft = function finishDraft (draft, patchListener) {
  var state = draft && draft[DRAFT_STATE];

  if (!state || !state.isManual) {
    throw new Error("First argument to `finishDraft` must be a draft returned by `createDraft`"); // prettier-ignore
  }

  if (state.finalized) {
    throw new Error("The given draft is already finalized"); // prettier-ignore
  }

  var scope = state.scope;
  scope.usePatches(patchListener);
  return this.processResult(undefined, scope);
};

Immer.prototype.setAutoFreeze = function setAutoFreeze (value) {
  this.autoFreeze = value;
};

Immer.prototype.setUseProxies = function setUseProxies (value) {
  this.useProxies = value;
  assign(this, value ? modernProxy : legacyProxy);
};

Immer.prototype.applyPatches = function applyPatches$1 (base, patches) {
  // Mutate the base state when a draft is passed.
  if (isDraft(base)) {
    return applyPatches(base, patches);
  } // Otherwise, produce a copy of the base state.


  return this.produce(base, function (draft) { return applyPatches(draft, patches); });
};
/** @internal */


Immer.prototype.processResult = function processResult (result, scope) {
  var baseDraft = scope.drafts[0];
  var isReplaced = result !== undefined && result !== baseDraft;
  this.willFinalize(scope, result, isReplaced);

  if (isReplaced) {
    if (baseDraft[DRAFT_STATE].modified) {
      scope.revoke();
      throw new Error("An immer producer returned a new value *and* modified its draft. Either return a new value *or* modify the draft."); // prettier-ignore
    }

    if (isDraftable(result)) {
      // Finalize the result in case it contains (or is) a subset of the draft.
      result = this.finalize(result, null, scope);
    }

    if (scope.patches) {
      scope.patches.push({
        op: "replace",
        path: [],
        value: result
      });
      scope.inversePatches.push({
        op: "replace",
        path: [],
        value: baseDraft[DRAFT_STATE].base
      });
    }
  } else {
    // Finalize the base draft.
    result = this.finalize(baseDraft, [], scope);
  }

  scope.revoke();

  if (scope.patches) {
    scope.patchListener(scope.patches, scope.inversePatches);
  }

  return result !== NOTHING ? result : undefined;
};
/**
 * @internal
 * Finalize a draft, returning either the unmodified base state or a modified
 * copy of the base state.
 */


Immer.prototype.finalize = function finalize (draft, path, scope) {
    var this$1 = this;

  var state = draft[DRAFT_STATE];

  if (!state) {
    if (Object.isFrozen(draft)) { return draft; }
    return this.finalizeTree(draft, null, scope);
  } // Never finalize drafts owned by another scope.


  if (state.scope !== scope) {
    return draft;
  }

  if (!state.modified) {
    return state.base;
  }

  if (!state.finalized) {
    state.finalized = true;
    this.finalizeTree(state.draft, path, scope);

    if (this.onDelete) {
      // The `assigned` object is unreliable with ES5 drafts.
      if (this.useProxies) {
        var assigned = state.assigned;

        for (var prop in assigned) {
          if (!assigned[prop]) { this.onDelete(state, prop); }
        }
      } else {
        var base = state.base;
          var copy = state.copy;
        each(base, function (prop) {
          if (!has(copy, prop)) { this$1.onDelete(state, prop); }
        });
      }
    }

    if (this.onCopy) {
      this.onCopy(state);
    } // At this point, all descendants of `state.copy` have been finalized,
    // so we can be sure that `scope.canAutoFreeze` is accurate.


    if (this.autoFreeze && scope.canAutoFreeze) {
      Object.freeze(state.copy);
    }

    if (path && scope.patches) {
      generatePatches(state, path, scope.patches, scope.inversePatches);
    }
  }

  return state.copy;
};
/**
 * @internal
 * Finalize all drafts in the given state tree.
 */


Immer.prototype.finalizeTree = function finalizeTree (root, rootPath, scope) {
    var this$1 = this;

  var state = root[DRAFT_STATE];

  if (state) {
    if (!this.useProxies) {
      // Create the final copy, with added keys and without deleted keys.
      state.copy = shallowCopy(state.draft, true);
    }

    root = state.copy;
  }

  var needPatches = !!rootPath && !!scope.patches;

  var finalizeProperty = function (prop, value, parent) {
    if (value === parent) {
      throw Error("Immer forbids circular references");
    } // In the `finalizeTree` method, only the `root` object may be a draft.


    var isDraftProp = !!state && parent === root;

    if (isDraft(value)) {
      var path = isDraftProp && needPatches && !state.assigned[prop] ? rootPath.concat(prop) : null; // Drafts owned by `scope` are finalized here.

      value = this$1.finalize(value, path, scope); // Drafts from another scope must prevent auto-freezing.

      if (isDraft(value)) {
        scope.canAutoFreeze = false;
      } // Preserve non-enumerable properties.


      if (Array.isArray(parent) || isEnumerable(parent, prop)) {
        parent[prop] = value;
      } else {
        Object.defineProperty(parent, prop, {
          value: value
        });
      } // Unchanged drafts are never passed to the `onAssign` hook.


      if (isDraftProp && value === state.base[prop]) { return; }
    } // Unchanged draft properties are ignored.
    else if (isDraftProp && is(value, state.base[prop])) {
        return;
      } // Search new objects for unfinalized drafts. Frozen objects should never contain drafts.
      else if (isDraftable(value) && !Object.isFrozen(value)) {
          each(value, finalizeProperty);
        }

    if (isDraftProp && this$1.onAssign) {
      this$1.onAssign(state, prop, value);
    }
  };

  each(root, finalizeProperty);
  return root;
};

var immer = new Immer();
/**
 * The `produce` function takes a value and a "recipe function" (whose
 * return value often depends on the base state). The recipe function is
 * free to mutate its first argument however it wants. All mutations are
 * only ever applied to a __copy__ of the base state.
 *
 * Pass only a function to create a "curried producer" which relieves you
 * from passing the recipe function every time.
 *
 * Only plain objects and arrays are made mutable. All other objects are
 * considered uncopyable.
 *
 * Note: This function is __bound__ to its `Immer` instance.
 *
 * @param {any} base - the initial state
 * @param {Function} producer - function that receives a proxy of the base state as first argument and which can be freely modified
 * @param {Function} patchListener - optional function that will be called with all the patches produced here
 * @returns {any} a new state, or the initial state if nothing was modified
 */

var produce = immer.produce;
/**
 * Pass true to automatically freeze all copies created by Immer.
 *
 * By default, auto-freezing is disabled in production.
 */

var setAutoFreeze = immer.setAutoFreeze.bind(immer);
/**
 * Pass true to use the ES2015 `Proxy` class when creating drafts, which is
 * always faster than using ES5 proxies.
 *
 * By default, feature detection is used, so calling this is rarely necessary.
 */

var setUseProxies = immer.setUseProxies.bind(immer);
/**
 * Apply an array of Immer patches to the first argument.
 *
 * This function is a producer, which means copy-on-write is in effect.
 */

var applyPatches$1 = immer.applyPatches.bind(immer);
/**
 * Create an Immer draft from the given base state, which may be a draft itself.
 * The draft can be modified until you finalize it with the `finishDraft` function.
 */

var createDraft = immer.createDraft.bind(immer);
/**
 * Finalize an Immer draft from a `createDraft` call, returning the base state
 * (if no changes were made) or a modified copy. The draft must *not* be
 * mutated afterwards.
 *
 * Pass a function as the 2nd argument to generate Immer patches based on the
 * changes that were made.
 */

var finishDraft = immer.finishDraft.bind(immer);

export default produce;
export { Immer, applyPatches$1 as applyPatches, createDraft, finishDraft, DRAFTABLE as immerable, isDraft, isDraftable, NOTHING as nothing, original, produce, setAutoFreeze, setUseProxies };
//# sourceMappingURL=immer.module.js.map