Make null explicit with IPath

index.d.ts

@@ -1,22 +1,22 @@
 // Definitions file for map-transform
 declare function mapTransform (mapping: object): (data: object) => object
 
-export type IPath = string | null
+export type IPath = string
 
 export interface IFieldMapping {
-  path: IPath,
+  path: IPath | null,
   default?: any,
   defaultRev?: any
 }
 
 export interface IMapping {
   fields?: {
-    [key: string]: IPath | IFieldMapping
+    [key: string]: IPath | IFieldMapping | null
   },
-  path?: IPath,
-  pathRev?: IPath,
-  pathTo?: IPath,
-  pathToRev?: IPath
+  path?: IPath | null,
+  pathRev?: IPath | null,
+  pathTo?: IPath | null,
+  pathToRev?: IPath | null
 }
 
 type IDataProperty = string | number | object

package.json

@@ -1,6 +1,6 @@
 {
   "name": "map-transform",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Map and transform objects with mapping definitions",
   "main": "index.js",
   "types": "index.d.ts",

src/lib/createFieldMapper.ts

@@ -2,11 +2,11 @@ import * as R from 'ramda'
 import { IFieldMapping, IFieldMapper, IPath } from '../../index.d'
 import lensPath from './lensPath'
 
-type IFieldMappingTuple = [string, IPath | IFieldMapping]
+type IFieldMappingTuple = [string, IPath | IFieldMapping | null]
 type IFieldMapperGetter = (isRev: boolean) => IFieldMapper
 
 // String | b -> b
-const normalizeFieldMapping = (fieldMapping: IPath | IFieldMapping): IFieldMapping =>
+const normalizeFieldMapping = (fieldMapping: IPath | IFieldMapping | null): IFieldMapping =>
   (!fieldMapping || typeof fieldMapping === 'string')
     ? { path: fieldMapping }
     : fieldMapping

src/lib/lensPath.ts

@@ -10,9 +10,8 @@ const parseIntIf = (val: string) => {
 }
 
 // String -> (String | Number)[]
-const preparePath = (path: IPath): (string | number)[] => (path)
-  ? path.split(/\[|]?\./).map((val: string) => parseIntIf(val))
-  : []
+const preparePath = (path: IPath): (string | number)[] =>
+  path.split(/\[|]?\./).map((val: string) => parseIntIf(val))
 
 /**
  * Take a path string and return a Ramda lens. If path is null or undefined, an
@@ -25,6 +24,6 @@ const preparePath = (path: IPath): (string | number)[] => (path)
  * @param {string} path - A path string in dot notation
  * @returns {Lens} A Ramda lens
  */
-const lensPath = (path?: IPath): R.Lens => (path) ? R.lensPath(preparePath(path)) : empty
+const lensPath = (path?: IPath | null): R.Lens => (path) ? R.lensPath(preparePath(path)) : empty
 
 export default lensPath