fixed flat typings, added example

__tests__/general.test.ts

@@ -0,0 +1,51 @@
+import { extend } from '../src/Symbol'
+import { ObjectEntry, Indexed } from '../src/types'
+
+describe('General', () => {
+    it('should find dependencies with different versions', () => {
+
+        const p1 = {
+            'name': 'package1',
+            'version': '1.0.0',
+            'devDependencies': {
+                'jest': '23.6.0',
+                'prettier': '1.15.3'
+            }
+        }
+
+        const p2 = {
+            'name': 'package2',
+            'version': '1.0.0',
+            'devDependencies': {
+                'jest': '22.0.0',
+                'prettier': '1.15.3'
+            }
+        }
+
+        function toHaveMoreVersions(entry: ObjectEntry<ObjectEntry<string>[]>): boolean {
+            return entry.value[extend]()
+                .unique()
+                .length > 1
+        }
+
+        function toInvalidDependency(entry: ObjectEntry<ObjectEntry<string>[]>) {
+            return {
+                name: entry.key,
+                versions: entry.value.map(e => e.value)
+            }
+        }
+
+        const invalidDeps = [p1, p2]
+            .map(pck => pck.devDependencies as Indexed<string>) // object[]
+            .map(pck => pck[extend]().entries())[extend]() // {key, value}[][]
+            .flat()[extend]() // {key, value}[]
+            .groupBy('key')[extend]() // {dependencyName: {name: version}[]}
+            .entries() // {key, value}[]
+            .filter(toHaveMoreVersions)
+            .map(toInvalidDependency)
+        expect(invalidDeps).toHaveLength(1)
+        expect(invalidDeps[0].name).toBe('jest')
+        expect(invalidDeps[0].versions).toMatchObject(['23.6.0', '22.0.0'])
+
+    })
+})

package.json

@@ -1,10 +1,32 @@
 {
   "name": "declarative-js-symbols",
   "version": "1.0.0",
+  "author": "Pavel Surinin <pavel.surinin@gmail.com>",
   "description": "Symbols to extend  JavaScript Array and Object prototypes with declarative-js functionality.",
   "main": "index.js",
   "types": "index.d.ts",
   "homepage": "https://pavel-surinin.github.io/declarativejssymbols/#/",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/pavel-surinin/declarativejssymbols"
+  },
+  "badges": [
+    {
+      "description": "Build Status",
+      "href": "https://travis-ci.org/pavel-surinin/declarative-js-symbols",
+      "url": "https://travis-ci.org/pavel-surinin/declarativejssymbols.svg?branch=master"
+    },
+    {
+      "description": "Coverage Status",
+      "href": "https://coveralls.io/github/pavel-surinin/declarativejssymbols?branch=master",
+      "url": "https://coveralls.io/repos/github/pavel-surinin/declarativejssymbols/badge.svg?branch=master"
+    }
+  ],
+  "bugs": {
+    "url": "https://github.com/pavel-surinin/declarativejssymbols/issues",
+    "email": "pavel.surinin@gmail.com"
+  },
   "scripts": {
     "test": "jest",
     "lint": "tslint --project ./tsconfig.json",
@@ -21,8 +43,6 @@
     "docs:commit": "npm run docsify && git add . && git commit -m \"Updated generated documentation\" && git push",
     "docs:start": "docsify serve ./docs"
   },
-  "author": "Pavel Surinin <pavel.surinin@gmail.com>",
-  "license": "ISC",
   "dependencies": {
     "declarative-js": "3.2.5"
   },
@@ -36,4 +56,4 @@
     "tslint": "5.10.0",
     "typescript": "3.2.2"
   }
-}
+}

readme.md

@@ -6,6 +6,11 @@
 
 Symbol that extends `array` and `object` with additional functions from declarative-js package.
 
+## Install
+```
+npm i declarative-js-symbols --save
+```
+
 ## Usage
 ```javascript
 import { extends } from 'declarative-js-symbols'
@@ -21,6 +26,52 @@ const transformedData =
         .groupBy('taskName')
 ```
 
+Imagine, that we maintain two npm packages and want to ensure that all dependencies have same versions.
+```javascript
+import { extends } from 'declarative-js-symbols'
+
+const p1 = {
+    "name": "package1",
+    "version": "1.0.0",
+    "devDependencies": {
+        "jest": "23.6.0", // <==
+        "prettier": "1.15.3"
+    }
+}
+const p2 = {
+    "name": "package2",
+    "version": "1.0.0",
+    "devDependencies": {
+        "jest": "22.0.0", // <==
+        "prettier": "1.15.3"
+    }
+}
+
+function toHaveMoreVersions(entry) {
+    return entry.value[extends]()
+        .unique()
+        .length > 1
+}
+
+function toInvalidDependency(entry) {
+    return {
+            name: entry.key, 
+            versions: entry.value.map(e => e.value)
+        }
+}
+
+const invalidDeps = [p1, p2]
+    .map(pck => pck.devDependencies) // object[]
+    .map(pck => pck[extend]().entries())[extend]() // {key, value}[][]
+    .flat()[extend]() // {key, value}[]
+    .groupBy('key')[extend]() // {dependencyName: {name: version}[]}
+    .entries() // {key, value}[]
+    .filter(toHaveMoreVersions)
+    .map(toInvalidDependency)
+// [{name: 'Jest', versions: ['23.6.0', '22.0.0']}]
+
+```
+
 ## Array
 
 ### equal
@@ -146,7 +197,7 @@ interface ArrayExtension<T> {
 Function to make from 2d array simple array
 ```typescript
 interface ArrayExtension<T> {
-    flat(): Array<T>
+    flat(): T
 }
 ```
 ```javascript

src/types/ArrayTypes.ts

@@ -124,7 +124,7 @@ export type ArrayExtension<T> = {
      * @example
      * [[1,2],[3,4]][extend]().flat() // [1,2,3,4]
      */
-    flat(): Array<T>
+    flat(): T
     /**
      * Collects items to object by key from callback. If function resolves key,
      * that already exists it will throw an Error. Second callback is value mapper.

src/types/ObjectTypes.ts

@@ -1,7 +1,7 @@
 import { extend } from '../Symbol'
 declare global {
     interface Object {
-        [extend](): ObjectExtension<any>
+        [extend]<T>(): ObjectExtension<T>
     }
 }
 export type ObjectExtension<T> = {