refactor: remove state pattern and call helpers with correct this c…

…ontext

This means that even helpers could be individually required.

```js
PouchDB.plugin({
  add: require('pouchdb-hoodie-api/helpers/add-one')
})
```

lib/add.js

@@ -4,12 +4,7 @@ var addOne = require('./helpers/add-one')
 var addMany = require('./helpers/add-many')
 
 module.exports = function add (objects) {
-  var isArray = Array.isArray(objects)
-  var state = {
-    db: this,
-    Promise: this.constructor.utils.Promise,
-    errors: this.constructor.Errors
-  }
-
-  return isArray ? addMany(state, objects) : addOne(state, objects)
+  return Array.isArray(objects) ?
+    addMany.call(this, objects) :
+    addOne.call(this, objects)
 }

lib/find-or-add.js

@@ -4,12 +4,7 @@ var findOrAddOne = require('./helpers/find-or-add-one')
 var findOrAddMany = require('./helpers/find-or-add-many')
 
 module.exports = function findOrAdd (idOrObjectOrArray, newObject) {
-  var state = {
-    db: this,
-    Promise: this.constructor.utils.Promise,
-    errors: this.constructor.Errors
-  }
-  var isArray = Array.isArray(idOrObjectOrArray)
-
-  return isArray ? findOrAddMany(state, idOrObjectOrArray) : findOrAddOne(state, idOrObjectOrArray, newObject)
+  return Array.isArray(idOrObjectOrArray) ?
+    findOrAddMany.call(this, idOrObjectOrArray) :
+    findOrAddOne.call(this, idOrObjectOrArray, newObject)
 }

lib/find.js

@@ -4,11 +4,7 @@ var findOne = require('./helpers/find-one')
 var findMany = require('./helpers/find-many')
 
 module.exports = function find (objectsOrIds) {
-  var state = {
-    db: this,
-    errors: this.constructor.Errors
-  }
-  var isArray = Array.isArray(objectsOrIds)
-
-  return isArray ? findMany(state, objectsOrIds) : findOne(state, objectsOrIds)
+  return Array.isArray(objectsOrIds) ?
+    findMany.call(this, objectsOrIds) :
+    findOne.call(this, objectsOrIds)
 }

lib/helpers/add-many.js

@@ -2,10 +2,11 @@
 
 var toDoc = require('../utils/to-doc')
 
-module.exports = function addMany (state, objects) {
+module.exports = function addMany (objects) {
   var docs = objects.map(toDoc)
 
-  return state.db.bulkDocs(docs)
+  return this.bulkDocs(docs)
+
   .then(function (responses) {
     return responses.map(function (response, i) {
       if (response instanceof Error) return response

lib/helpers/add-one.js

@@ -2,13 +2,18 @@
 
 var toDoc = require('../utils/to-doc')
 
-module.exports = function addOne (state, object) {
+module.exports = function addOne (object) {
+  var Promise = this.constructor.utils.Promise
+  var errors = this.constructor.Errors
+
   if (typeof object !== 'object') {
-    return state.Promise.reject(state.errors.NOT_AN_OBJECT)
+    return Promise.reject(errors.NOT_AN_OBJECT)
   }
 
   var method = object.id ? 'put' : 'post'
-  return state.db[method](toDoc(object))
+
+  return this[method](toDoc(object))
+
   .then(function (response) {
     object.id = response.id
     object._rev = response.rev

lib/helpers/find-many.js

@@ -3,10 +3,11 @@
 var toId = require('../utils/to-id')
 var toObject = require('../utils/to-object')
 
-module.exports = function findMany (state, idsOrObjects) {
+module.exports = function findMany (idsOrObjects) {
+  var errors = this.constructor.Errors
   var ids = idsOrObjects.map(toId)
 
-  return state.db.allDocs({keys: ids, include_docs: true})
+  return this.allDocs({keys: ids, include_docs: true})
 
   .then(function (response) {
     var foundMap = response.rows.reduce(function (map, row) {
@@ -17,7 +18,7 @@ module.exports = function findMany (state, idsOrObjects) {
       var doc = foundMap[id]
       if (doc) return doc
 
-      return state.errors.MISSING_DOC
+      return errors.MISSING_DOC
     })
 
     return docs.map(toObject)

lib/helpers/find-one.js

@@ -3,7 +3,7 @@
 var toId = require('../utils/to-id')
 var toObject = require('../utils/to-object')
 
-module.exports = function findOne (state, idOrObject) {
+module.exports = function findOne (idOrObject) {
   var id = toId(idOrObject)
-  return state.db.get(id).then(toObject)
+  return this.get(id).then(toObject)
 }

lib/helpers/find-or-add-many.js

@@ -2,11 +2,12 @@ var toId = require('../utils/to-id')
 var findMany = require('./find-many')
 var addMany = require('./add-many')
 
-module.exports = function findOrAddMany (state, passedObjects) {
+module.exports = function findOrAddMany (passedObjects) {
+  var self = this
   var foundObjects
   var passedObjectIds = passedObjects.map(toId)
 
-  return findMany(state, passedObjectIds)
+  return findMany.call(this, passedObjectIds)
 
   .then(function (_foundObjects) {
     foundObjects = _foundObjects
@@ -19,7 +20,7 @@ module.exports = function findOrAddMany (state, passedObjects) {
       return notFoundObjects
     }, [])
 
-    return addMany(state, notFoundObjects)
+    return addMany.call(self, notFoundObjects)
   })
 
   .then(function (addedObjects) {

lib/helpers/find-or-add-one.js

@@ -2,23 +2,27 @@ var toId = require('../utils/to-id')
 var findOne = require('./find-one')
 var addOne = require('./add-one')
 
-module.exports = function findOrAddOne (state, idOrObject, newObject) {
+module.exports = function findOrAddOne (idOrObject, newObject) {
+  var self = this
+  var Promise = this.constructor.utils.Promise
+  var errors = this.constructor.Errors
   var id = toId(idOrObject)
 
-  if (!id) return state.Promise.reject(state.errors.MISSING_ID)
+  if (!id) return Promise.reject(errors.MISSING_ID)
 
   if (idOrObject === id && !newObject) {
-    return state.Promise.reject(state.errors.MISSING_ID)
+    return Promise.reject(errors.MISSING_ID)
   }
 
-  return findOne(state, id)
+  return findOne.call(this, id)
+
   .catch(function (/*error*/) {
     if (typeof newObject === 'object') {
       newObject.id = id
     } else {
       newObject = idOrObject
     }
 
-    return addOne(state, newObject)
+    return addOne.call(self, newObject)
   })
 }

lib/helpers/update-many.js

@@ -7,11 +7,13 @@ var toDoc = require('../utils/to-doc')
 var toId = require('../utils/to-id')
 var findMany = require('./find-many')
 
-module.exports = function updateMany (state, array, change) {
+module.exports = function updateMany (array, change) {
+  var self = this
+  var errors = this.constructor.Errors
   var objects
   var ids = array.map(toId)
 
-  return findMany(state, array)
+  return findMany.call(this, array)
 
   .then(function (objects) {
     if (change) {
@@ -24,7 +26,7 @@ module.exports = function updateMany (state, array, change) {
     return objects.map(function (object, index) {
       var passedObject = array[index]
       if (object instanceof Error) return object
-      if (typeof passedObject !== 'object') return state.errors.NOT_AN_OBJECT
+      if (typeof passedObject !== 'object') return errors.NOT_AN_OBJECT
       return extend(object, passedObject)
     })
   })
@@ -34,7 +36,7 @@ module.exports = function updateMany (state, array, change) {
     var validObjects = objects.filter(function (object) {
       return !(object instanceof Error)
     })
-    return state.db.bulkDocs(validObjects.map(toDoc))
+    return self.bulkDocs(validObjects.map(toDoc))
   })
 
   .then(function (responses) {

lib/helpers/update-one.js

@@ -6,14 +6,17 @@ var changeObject = require('../utils/change-object')
 var toDoc = require('../utils/to-doc')
 var findOne = require('./find-one')
 
-module.exports = function updateOne (state, idOrObject, change) {
+module.exports = function updateOne (idOrObject, change) {
+  var self = this
+  var Promise = this.constructor.utils.Promise
+  var errors = this.constructor.Errors
   var object
 
   if (typeof idOrObject === 'string' && !change) {
-    return state.Promise.reject(state.errors.NOT_AN_OBJECT)
+    return Promise.reject(errors.NOT_AN_OBJECT)
   }
 
-  return findOne(state, idOrObject)
+  return findOne.call(this, idOrObject)
 
   .then(function (object) {
     if (!change) return extend(object, idOrObject)
@@ -22,7 +25,7 @@ module.exports = function updateOne (state, idOrObject, change) {
 
   .then(function (_object) {
     object = _object
-    return state.db.put(toDoc(object))
+    return self.put(toDoc(object))
   })
 
   .then(function (response) {

lib/helpers/update-or-add-many.js

@@ -2,11 +2,12 @@ var toId = require('../utils/to-id')
 var addMany = require('./add-many')
 var updateMany = require('./update-many')
 
-module.exports = function updateOrAddMany (state, passedObjects) {
+module.exports = function updateOrAddMany (passedObjects) {
+  var self = this
   var addedObjects
   var passedObjectIds = passedObjects.map(toId)
 
-  return addMany(state, passedObjects)
+  return addMany.call(this, passedObjects)
 
   .then(function (_addedObjectsAndErrors) {
     addedObjects = _addedObjectsAndErrors
@@ -20,7 +21,7 @@ module.exports = function updateOrAddMany (state, passedObjects) {
       return array
     }, [])
 
-    return updateMany(state, conflicting)
+    return updateMany.call(self, conflicting)
   })
 
   .then(function (updatedObjects) {

lib/helpers/update-or-add-one.js

@@ -2,17 +2,18 @@ var toId = require('../utils/to-id')
 var addOne = require('./add-one')
 var updateOne = require('./update-one')
 
-module.exports = function updateOrAddOne (state, idOrObject, newObject) {
-  return updateOne(state, idOrObject, newObject)
+module.exports = function updateOrAddOne (idOrObject, newObject) {
+  var self = this
+  return updateOne.call(this, idOrObject, newObject)
 
   .catch(function (error) {
     if (error.status !== 404) throw error
 
     if (newObject) {
       newObject.id = toId(idOrObject)
-      return addOne(state, newObject)
+      return addOne.call(self, newObject)
     }
 
-    return addOne(state, idOrObject)
+    return addOne.call(self, idOrObject)
   })
 }

lib/remove.js

@@ -4,13 +4,7 @@ var updateOne = require('./helpers/update-one')
 var updateMany = require('./helpers/update-many')
 
 module.exports = function remove (objectsOrIds) {
-  var state = {
-    db: this,
-    Promise: this.constructor.utils.Promise,
-    errors: this.constructor.Errors
-  }
-  var isArray = Array.isArray(objectsOrIds)
-
-  return isArray ? updateMany(state, objectsOrIds, {_deleted: true})
-                 : updateOne(state, objectsOrIds, {_deleted: true})
+  return Array.isArray(objectsOrIds) ?
+    updateMany.call(this, objectsOrIds, {_deleted: true}) :
+    updateOne.call(this, objectsOrIds, {_deleted: true})
 }

lib/update-or-add.js

@@ -4,12 +4,7 @@ var updateOrAddOne = require('./helpers/update-or-add-one')
 var updateOrAddMany = require('./helpers/update-or-add-many')
 
 module.exports = function updateOrAdd (idOrObjectOrArray, newObject) {
-  var state = {
-    db: this,
-    Promise: this.constructor.utils.Promise,
-    errors: this.constructor.Errors
-  }
-  var isArray = Array.isArray(idOrObjectOrArray)
-
-  return isArray ? updateOrAddMany(state, idOrObjectOrArray) : updateOrAddOne(state, idOrObjectOrArray, newObject)
+  return Array.isArray(idOrObjectOrArray) ?
+    updateOrAddMany.call(this, idOrObjectOrArray) :
+    updateOrAddOne.call(this, idOrObjectOrArray, newObject)
 }

lib/update.js

@@ -4,13 +4,13 @@ var updateOne = require('./helpers/update-one')
 var updateMany = require('./helpers/update-many')
 
 module.exports = function update (objectsOrIds, change) {
-  var Promise = this.constructor.utils.Promise
-  var state = { db: this, Promise: Promise, errors: this.constructor.Errors }
-  var isArray = Array.isArray(objectsOrIds)
-
   if (typeof objectsOrIds !== 'object' && !change) {
-    return Promise.reject(new Error('Must provide change'))
+    return this.constructor.utils.Promise.reject(
+      new Error('Must provide change')
+    )
   }
 
-  return isArray ? updateMany(state, objectsOrIds, change) : updateOne(state, objectsOrIds, change)
+  return Array.isArray(objectsOrIds) ?
+    updateMany.call(this, objectsOrIds, change) :
+    updateOne.call(this, objectsOrIds, change)
 }