From ebd03ee7037b3fe7e42dad9362b8f39c67ab30c3 Mon Sep 17 00:00:00 2001
From: Andrei Dumitrescu <5057797+andreidcm@users.noreply.github.com>
Date: Fri, 28 Aug 2020 17:21:46 +0200
Subject: [PATCH] feat: Add "converge" functions

---
 src/converge/converge.js      | 46 +++++++++++++++++++++++++++++++++++
 src/converge/converge.test.js | 27 ++++++++++++++++++++
 src/index.js                  |  7 +++---
 3 files changed, 77 insertions(+), 3 deletions(-)
 create mode 100644 src/converge/converge.js
 create mode 100644 src/converge/converge.test.js

diff --git a/src/converge/converge.js b/src/converge/converge.js
new file mode 100644
index 0000000..8d1cf13
--- /dev/null
+++ b/src/converge/converge.js
@@ -0,0 +1,46 @@
+import { pipe } from "../pipe/pipe"
+
+const _converge = (_accFn, _extractFn, source) => {
+  const accFn = Array.isArray(_accFn) ? pipe(..._accFn) : _accFn
+  const extractFn = Array.isArray(_extractFn) ? _extractFn : [_extractFn]
+  const extractValues = []
+
+  for (let i = 0; i < extractFn.length; ++i) {
+    extractValues.push(extractFn[i](source))
+  }
+
+  return accFn(...extractValues)
+}
+
+/**
+ * Apply a list of function, extract functions, on the same input and use
+ * those results as parameters for another accumulator function.
+ *
+ * @param {Fn|Fn[]} accFn     Accumulator or final aggreate function
+ * @param {Fn|Fn[]} extractFn List of functions to be applied on input
+ * @param {Any}     source    Source input
+ *
+ * @return {Any}
+ *
+ * @name converge
+ * @tag Core
+ * @signature (accFn: Fn|Fn[], extractFn: Fn|Fn[]) => (source: Array): Any
+ * @signature (accFn: Fn|Fn[], extractFn: Fn|Fn[], source: Array): Any
+ *
+ * @example
+ * const divide = () => ...
+ * const sum = () => ...
+ * const count = () => ...
+ *
+ * converge(divide, [sum, count], [1, 2, 3, 4, 5, 6, 7])
+ * // => 4
+ */
+export const converge = (...params) => {
+  // @signature (accFn, extractFn) => (source)
+  if (params.length <= 2) {
+    return source => _converge(params[0], params[1], source)
+  }
+
+  // @signature (accFn, extractFn, source)
+  return _converge(...params)
+}
diff --git a/src/converge/converge.test.js b/src/converge/converge.test.js
new file mode 100644
index 0000000..5202608
--- /dev/null
+++ b/src/converge/converge.test.js
@@ -0,0 +1,27 @@
+import test from "tape"
+import { converge, reduce, read } from ".."
+
+test("converge", t => {
+  const obj = { a: 1, b: 2 }
+  const sum = (...params) => reduce((acc, item) => acc + item, 0, params)
+
+  t.equals(
+    converge(sum, [read("a"), read("b")])(obj),
+    3,
+    "Extract object properties + sum (curried)"
+  )
+
+  t.equals(
+    converge(sum, read("b"), obj),
+    2,
+    "Extract object property + sum (uncurried)"
+  )
+
+  t.equals(
+    converge([sum], [read("a"), read("b")], obj),
+    3,
+    "Extract object properties + sum (uncurried)"
+  )
+
+  t.end()
+})
diff --git a/src/index.js b/src/index.js
index 60e05c4..ec03296 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,11 +1,8 @@
-export { curry } from "./curry/curry"
-export { zipToObj } from "./zip-to-obj/zip-to-obj"
 export { isDeepEqual, isDeepEqual as deepEqual } from "./deep-equal/deep-equal"
 export { elapsedTime } from "./elapsed-time/elapsed-time"
 export { groupBy } from "./group-by/group-by"
 export { indexBy } from "./index-by/index-by"
 export { hist } from "./hist/hist"
-export { isMatch } from "./is-match/is-match"
 export { protoChain } from "./proto-chain/proto-chain"
 export { renameFile } from "./rename-file/rename-file"
 export { sequence, sequenceWhile } from "./sequence/sequence"
@@ -16,9 +13,11 @@ export { throttle } from "./throttle/throttle"
 export { debounce } from "./debounce/debounce"
 
 // Core
+export { curry } from "./curry/curry"
 export { map } from "./map/map"
 export { mapMatrix } from "./map-matrix/map-matrix"
 export { reduce } from "./reduce/reduce"
+export { converge } from "./converge/converge"
 export { forEach } from "./for-each/for-each"
 export { pipe } from "./pipe/pipe"
 export { pipeP } from "./pipeP/pipeP"
@@ -37,12 +36,14 @@ export { any, anyWith } from "./any/any"
 export { all, allWith } from "./all/all"
 export { when } from "./when/when"
 export { cases } from "./cases/cases"
+export { isMatch } from "./is-match/is-match"
 
 // Object
 export { pick } from "./pick/pick"
 export { pluck } from "./pluck/pluck"
 export { merge } from "./merge/merge"
 export { keys } from "./keys/keys"
+export { zipToObj } from "./zip-to-obj/zip-to-obj"
 
 // Array
 export { top } from "./top/top"