feat(Modules): Add lens along with assocPath

__tests__/modules/assoc.test.js

@@ -5,7 +5,7 @@ describe('assoc', () => {
     const key = 'name'
     const value = {}
     const obj = { name: 'John' }
-    const result = assoc(value, key, obj)
+    const result = assoc(key, value, obj)
 
     expect(result).toEqual({
       name: value
@@ -16,7 +16,7 @@ describe('assoc', () => {
     const key = 'name'
     const value = {}
     const obj = { name: 'John' }
-    const result = assoc(value)(key)(obj)
+    const result = assoc(key)(value)(obj)
 
     expect(result).toEqual({
       name: value

__tests__/modules/assocPath.test.js

@@ -0,0 +1,29 @@
+import assocPath from '../../modules/assocPath'
+
+describe('Associate Path', () => {
+  test('associates a value to a nested path', () => {
+    const data = {
+      a: {
+        b: {
+          c: 1
+        }
+      },
+      d: 1
+    }
+
+    const path = ['a', 'b', 'c']
+    const value = 2
+    const expected = {
+      a: {
+        b: {
+          c: 2
+        }
+      },
+      d: 1
+    }
+
+    const actual = assocPath(path, value, data)
+
+    expect(actual).toEqual(expected)
+  })
+})

__tests__/modules/over.test.js

@@ -0,0 +1,27 @@
+import over from '../../modules/over'
+import lensProp from '../../modules/lensProp'
+
+describe('Over', () => {
+  test('It sets the value at the given lens by applying the given function', () => {
+    const data = {
+      name: 'Tim',
+      age: 29
+    }
+
+    const nameLens = lensProp('name')
+
+    const setName = name => {
+      expect(name).toBe('Tim')
+      return 'John'
+    }
+
+    const expected = {
+      name: 'John',
+      age: 29
+    }
+
+    const actual = over(nameLens, setName, data)
+
+    expect(actual).toEqual(expected)
+  })
+})

__tests__/modules/set.test.js

@@ -0,0 +1,22 @@
+import set from '../../modules/set'
+import lensProp from '../../modules/lensProp'
+
+describe('Set', () => {
+  test('It sets the given value on the given lens in the given data', () => {
+    const data = {
+      name: 'Tim',
+      age: 29
+    }
+
+    const nameLens = lensProp('name')
+
+    const expected = {
+      name: 'John',
+      age: 29
+    }
+
+    const actual = set(nameLens, 'John', data)
+
+    expect(actual).toEqual(expected)
+  })
+})

__tests__/modules/view.test.js

@@ -0,0 +1,17 @@
+import view from '../../modules/view'
+import lensProp from '../../modules/lensProp'
+
+describe('View', () => {
+  test('It returns the value at the lens', () => {
+    const data = {
+      name: 'Tim',
+      age: 29
+    }
+
+    const nameLens = lensProp('name')
+    const expected = 'Tim'
+    const actual = view(nameLens, data)
+
+    expect(actual).toBe(expected)
+  })
+})

modules/assoc.js

@@ -8,12 +8,12 @@ import curry from './curry'
  *  assoc(1, 'age', { age: 2, name: 'Tim' }) === { age: 1, name: 'Tim' }
  * 
  *
- * @param {*} value - The value to associate
  * @param {string} key - The key to associate
+ * @param {*} value - The value to associate
  * @param {Object} obj - The structure to associate with
  * @return {Object}
  */
-const assoc = (value, key, obj) => {
+const assoc = (key, value, obj) => {
   let result = {}
 
   for (let k in obj) {

modules/assocPath.js

@@ -0,0 +1,35 @@
+import curry from './curry'
+import clone from './clone'
+import cloneType from './cloneType'
+import assoc from './assoc'
+import prop from './prop'
+
+/**
+ * Associates a value at a path
+ * 
+ * @example
+ *
+ *  assocPath(['profile', 'age'], 30, { profile: { age: 29 } } ) === { profile: { age: 30 } }
+ * 
+ *
+ * @param {Array<string|number>} key - The path to associate
+ * @param {*} value - The value to associate
+ * @param {Object} obj - The structure to associate with
+ * @return {Object}
+ */
+export const assocPath = (targetPath, value, data) => {
+  // Ensure we are not mutating anything
+  const path = targetPath.slice()
+
+  // If we are at the end of our recursion
+  if (path.length < 2) {
+    return assoc(targetPath.shift(), value, data)
+  }
+
+  const key = path.shift()
+
+  // Associate the top key with the recursive result
+  return assoc(key, assocPath(path, value, prop(key, data)), data)
+}
+
+export default curry(assocPath)

modules/cloneType.js

@@ -0,0 +1,7 @@
+export const cloneType = base => {
+  if (Array.isArray(base)) {
+    return []
+  }
+
+  return {}
+}

modules/lens.js

@@ -0,0 +1,14 @@
+import curry from './curry'
+
+/**
+ * A way to get and set values in a data structure
+ * 
+ * @param {function(any) => any} get 
+ * @param {function(any, a) => a} set 
+ */
+export const lens = (get, set) => ({
+  get,
+  set
+})
+
+export default curry(lens)

modules/lensPath.js

@@ -0,0 +1,14 @@
+import curry from './curry'
+import path from './path'
+import lens from './lens'
+import assocPath from './assocPath'
+
+/**
+ * A way to create a lens for a given path
+ * 
+ * @param {Array<string|number>} keys - The path to the data we care about
+ * @returns {Lens} - A lens to the Path
+ */
+export const lensPath = keys => lens(path(keys), assocPath(keys))
+
+export default curry(lensPath)

modules/lensProp.js

@@ -0,0 +1,12 @@
+import curry from './curry'
+import lensPath from './lensPath'
+
+/**
+ * Creates a lens at a given path
+ * 
+ * @param {string|number} key - The key to associate this lens with
+ * @return {Lens}
+ */
+export const lensProp = key => lensPath([key])
+
+export default curry(lensProp)

modules/over.js

@@ -0,0 +1,15 @@
+import curry from './curry'
+
+/**
+ * A way to set a value on a lens via a function
+ * The function gets passed the value at the key along with the 
+ * data structure
+ * 
+ * @param {Lens} lens - The lens to the value to set 
+ * @param {function(*, *) => *} fn - A function to immutably create a new value 
+ * @param {*} data - The data to look in
+ * @return {*} 
+ */
+export const over = (lens, fn, data) => lens.set(fn(lens.get(data)), data)
+
+export default curry(over)

modules/set.js

@@ -0,0 +1,13 @@
+import curry from './curry'
+
+/**
+ * Sets the given value at the given lens
+ * 
+ * @param {Lens} lens - The lens to the value 
+ * @param {*} value - The value to set at the lens 
+ * @param {*} data - The data structure to look in
+ * @return {*} - The data with the lens set
+ */
+export const set = (lens, value, data) => lens.set(value, data)
+
+export default curry(set)

modules/view.js

@@ -0,0 +1,12 @@
+import curry from './curry'
+
+/**
+ * A way to actually view the value
+ * 
+ * @param {Lens} lens - The lens to the data 
+ * @param {*} data - The data structure to look in
+ * @return {*} 
+ */
+export const view = (lens, data) => lens.get(data)
+
+export default curry(view)

yarn.lock

@@ -1511,7 +1511,7 @@ debug@^3.0.1, debug@^3.1.0:
   dependencies:
     ms "2.0.0"
 
-debuglog@*, debuglog@^1.0.1:
+debuglog@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/debuglog/-/debuglog-1.0.1.tgz#aa24ffb9ac3df9a2351837cfb2d279360cd78492"
 
@@ -2866,7 +2866,7 @@ import-lazy@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/import-lazy/-/import-lazy-2.1.0.tgz#05698e3d45c88e8d7e9d92cb0584e77f096f3e43"
 
-imurmurhash@*, imurmurhash@^0.1.4:
+imurmurhash@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/imurmurhash/-/imurmurhash-0.1.4.tgz#9218b9b2b928a238b13dc4fb6b6d576f231453ea"
 
@@ -3765,25 +3765,17 @@ lodash._basecopy@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/lodash._basecopy/-/lodash._basecopy-3.0.1.tgz#8da0e6a876cf344c0ad8a54882111dd3c5c7ca36"
 
-lodash._baseindexof@*:
-  version "3.1.0"
-  resolved "https://registry.yarnpkg.com/lodash._baseindexof/-/lodash._baseindexof-3.1.0.tgz#fe52b53a1c6761e42618d654e4a25789ed61822c"
-
 lodash._baseuniq@~4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/lodash._baseuniq/-/lodash._baseuniq-4.6.0.tgz#0ebb44e456814af7905c6212fa2c9b2d51b841e8"
   dependencies:
     lodash._createset "~4.0.0"
     lodash._root "~3.0.0"
 
-lodash._bindcallback@*, lodash._bindcallback@^3.0.0:
+lodash._bindcallback@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/lodash._bindcallback/-/lodash._bindcallback-3.0.1.tgz#e531c27644cf8b57a99e17ed95b35c748789392e"
 
-lodash._cacheindexof@*:
-  version "3.0.2"
-  resolved "https://registry.yarnpkg.com/lodash._cacheindexof/-/lodash._cacheindexof-3.0.2.tgz#3dc69ac82498d2ee5e3ce56091bafd2adc7bde92"
-
 lodash._createassigner@^3.0.0:
   version "3.1.1"
   resolved "https://registry.yarnpkg.com/lodash._createassigner/-/lodash._createassigner-3.1.1.tgz#838a5bae2fdaca63ac22dee8e19fa4e6d6970b11"
@@ -3792,17 +3784,11 @@ lodash._createassigner@^3.0.0:
     lodash._isiterateecall "^3.0.0"
     lodash.restparam "^3.0.0"
 
-lodash._createcache@*:
-  version "3.1.2"
-  resolved "https://registry.yarnpkg.com/lodash._createcache/-/lodash._createcache-3.1.2.tgz#56d6a064017625e79ebca6b8018e17440bdcf093"
-  dependencies:
-    lodash._getnative "^3.0.0"
-
 lodash._createset@~4.0.0:
   version "4.0.3"
   resolved "https://registry.yarnpkg.com/lodash._createset/-/lodash._createset-4.0.3.tgz#0f4659fbb09d75194fa9e2b88a6644d363c9fe26"
 
-lodash._getnative@*, lodash._getnative@^3.0.0:
+lodash._getnative@^3.0.0:
   version "3.9.1"
   resolved "https://registry.yarnpkg.com/lodash._getnative/-/lodash._getnative-3.9.1.tgz#570bc7dede46d61cdcde687d65d3eecbaa3aaff5"
 
@@ -3862,7 +3848,7 @@ lodash.merge@^4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/lodash.merge/-/lodash.merge-4.6.0.tgz#69884ba144ac33fe699737a6086deffadd0f89c5"
 
-lodash.restparam@*, lodash.restparam@^3.0.0:
+lodash.restparam@^3.0.0:
   version "3.6.1"
   resolved "https://registry.yarnpkg.com/lodash.restparam/-/lodash.restparam-3.6.1.tgz#936a4e309ef330a7645ed4145986c85ae5b20805"
 
@@ -5138,7 +5124,7 @@ readable-stream@~2.0.5:
     string_decoder "~0.10.x"
     util-deprecate "~1.0.1"
 
-readdir-scoped-modules@*, readdir-scoped-modules@^1.0.0:
+readdir-scoped-modules@^1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/readdir-scoped-modules/-/readdir-scoped-modules-1.0.2.tgz#9fafa37d286be5d92cbaebdee030dc9b5f406747"
   dependencies:
@@ -6217,7 +6203,7 @@ uuid@^3.0.0, uuid@^3.1.0, uuid@~3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/uuid/-/uuid-3.1.0.tgz#3dd3d3e790abc24d7b0d3a034ffababe28ebbc04"
 
-validate-npm-package-license@*, validate-npm-package-license@^3.0.1:
+validate-npm-package-license@^3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/validate-npm-package-license/-/validate-npm-package-license-3.0.1.tgz#2804babe712ad3379459acfbe24746ab2c303fbc"
   dependencies: