added pipe package (#492)

* added `pipe` package

NOTE: I did not rollup config because I wasn't sure how I should configure it

* fix md-variables and add more tests for pipe

* generate readme for pipe

Co-authored-by: Thomas Clark <thomas.clark@bigtincan.com>

md-variables.json

@@ -1599,5 +1599,16 @@
       "const squareFn = (number) => number * number;",
       "deepMapValues({ a: 1, b: { c: 2, d: { e: 3 } } }, squareFn); // => { a: 1, b: { c: 4, d: { e: 9 } } }"
     ]
+  },
+  "just-pipe": {
+    "packageName": "just-pipe",
+    "dir": "function-pipe",
+    "description": "Pass a value through a pipeline of functions",
+    "examples": [
+      "import pipe from 'just-pipe",
+      "",
+      "pipe(3, a => a+1, b => b*2) // 8",
+      "pipe('John Smith', a => a.split(' '), b => b.reverse(), c => c[0]) // 'Smith'"
+    ]
   }
 }

packages/function-pipe/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 angus croll
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

packages/function-pipe/README.md

@@ -0,0 +1,25 @@
+<!-- DO NOT EDIT THIS FILE! THIS FILE WAS AUTOGENERATED BY TEMPLATE-MATE -->
+<!-- SEE https://github.com/angus-c/just/blob/master/CONTRIBUTING.md#readme-template -->
+
+## just-pipe
+
+Part of a [library](https://anguscroll.com/just) of zero-dependency npm modules that do just do one thing.
+Guilt-free utilities for every occasion.
+
+[`🍦 Try it`](https://anguscroll.com/just/just-pipe)
+
+```shell
+npm install just-pipe
+```
+```shell
+yarn add just-pipe
+```
+
+Pass a value through a pipeline of functions
+
+```js
+import pipe from 'just-pipe
+
+pipe(3, a => a+1, b => b*2) // 8
+pipe('John Smith', a => a.split(' '), b => b.reverse(), c => c[0]) // 'Smith'
+```

packages/function-pipe/index.d.ts

@@ -0,0 +1,79 @@
+declare function pipe<A, B>(value: A, ab: (a: A) => B): B
+
+declare function pipe<A, B, C>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+): C
+
+declare function pipe<A, B, C, D>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+  cd: (c: C) => D,
+): D
+
+declare function pipe<A, B, C, D, E>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+  cd: (c: C) => D,
+  de: (d: D) => E,
+): E
+
+declare function pipe<A, B, C, D, E, F>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+  cd: (c: C) => D,
+  de: (d: D) => E,
+  ef: (e: E) => F,
+): F
+
+declare function pipe<A, B, C, D, E, F, G>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+  cd: (c: C) => D,
+  de: (d: D) => E,
+  ef: (e: E) => F,
+  fg: (f: F) => G,
+): G
+
+declare function pipe<A, B, C, D, E, F, G, H>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+  cd: (c: C) => D,
+  de: (d: D) => E,
+  ef: (e: E) => F,
+  fg: (f: F) => G,
+  gh: (g: G) => H,
+): H
+
+declare function pipe<A, B, C, D, E, F, G, H, I>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+  cd: (c: C) => D,
+  de: (d: D) => E,
+  ef: (e: E) => F,
+  fg: (f: F) => G,
+  gh: (g: G) => H,
+  hi: (h: H) => I,
+): I
+
+declare function pipe<A, B, C, D, E, F, G, H, I, J>(
+  value: A,
+  ab: (a: A) => B,
+  bc: (b: B) => C,
+  cd: (c: C) => D,
+  de: (d: D) => E,
+  ef: (e: E) => F,
+  fg: (f: F) => G,
+  gh: (g: G) => H,
+  hi: (h: H) => I,
+  ij: (i: I) => J,
+): J
+
+export default pipe;

packages/function-pipe/index.js

@@ -0,0 +1,24 @@
+module.exports = pipe;
+
+/*
+pipe("hello", (a) => a.concat(" world")); // "hello world"
+pipe(5, a => a * 2, b => b + 1); // 11
+*/
+
+function pipe(value, ...fns) {
+  if (!arguments.length) {
+    throw new Error('expected one value argument and least one function argument');
+  }
+  if (!fns.length) {
+    throw new Error(
+      'expected at least one (and probably more) function arguments'
+    );
+  }
+
+  var result = fns[0](value);
+  var len = fns.length;
+  for (var i = 1; i < len; i++) {
+    result = fns[i](result);
+  }
+  return result;
+}

packages/function-pipe/index.mjs

@@ -0,0 +1,25 @@
+var functionPipe = pipe;
+/*
+pipe("hello", (a) => a.concat(" world")); // "hello world"
+pipe(5, a => a * 2, b => b + 1); // 11
+*/
+
+function pipe(value, ...fns) {
+  if (!arguments.length) {
+    throw new Error('expected one value argument and least one function argument');
+  }
+  if (!fns.length) {
+    throw new Error(
+      'expected at least one (and probably more) function arguments'
+    );
+  }
+
+  var result = fns[0](value);
+  var len = fns.length;
+  for (var i = 1; i < len; i++) {
+    result = fns[i](result);
+  }
+  return result;
+}
+
+export {functionPipe as default};

packages/function-pipe/index.tests.ts

@@ -0,0 +1,38 @@
+import pipe from './index';
+
+// Case 1) Value and 1 function
+pipe('hello', a => a.concat(' world'));
+
+// Case 2) Value and 2 functions
+pipe(
+  5,
+  a => a * 2,
+  b => b + 1
+);
+
+// Case 3) Value and 9 functions
+pipe(
+  {},
+  a => ({
+    ...a,
+    field: 'text',
+  }),
+  b => b.field,
+  c => c.concat(' value'),
+  d => d.length,
+  Math.sqrt,
+  f => f * f,
+  g => new Date(g),
+  h => h.toJSON(),
+  i => i.trim(),
+);
+
+//@ts-expect-error
+pipe();
+
+//@ts-expect-error
+pipe(5);
+
+const arr: unknown[] = [];
+//@ts-expect-error
+pipe(arr, Math.sqrt);

packages/function-pipe/package.json

@@ -0,0 +1,29 @@
+{
+  "name": "just-pipe",
+  "version": "1.0.0",
+  "description": "Pass a value through a pipeline of functions",
+  "main": "index.js",
+  "module": "index.mjs",
+  "exports": {
+    ".": {
+      "require": "./index.js",
+      "default": "./index.mjs"
+    }
+  },
+  "types": "index.d.ts",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "build": "rollup -c"
+  },
+  "repository": "https://github.com/angus-c/just",
+  "keywords": [
+    "pipe",
+    "function",
+    "just"
+  ],
+  "author": "Thomas Clark",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/angus-c/just/issues"
+  }
+}

test/function-pipe/index.js

@@ -0,0 +1,44 @@
+var test = require('../util/test')(__filename);
+var pipe = require('../../packages/function-pipe');
+var camelCase = require('../../packages/string-camel-case');
+var last = require('../../packages/array-last');
+
+test('Correctly pipes value through one or more functions', function(t) {
+  t.plan(4);
+  t.equal(pipe('hello world', camelCase), 'helloWorld');
+
+  function addOne(a) {
+    return a + 1;
+  }
+  function double(b) {
+    return b * 2;
+  }
+  t.equal(pipe(3, addOne, double), 8);
+  t.equal(pipe(3, double, addOne), 7);
+
+  function prependZero(arr) {
+    return [0, ...arr];
+  }
+  function reverse(arr) {
+    return [...arr].reverse();
+  }
+
+  t.equal(pipe([1, 2, 3], prependZero, reverse, last), 0);
+  t.end();
+});
+
+test('Throws if passed bad parameters', function(t) {
+  t.plan(3);
+
+  t.throws(function() {
+    pipe();
+  }, Error);
+  t.throws(function() {
+    pipe(5);
+  }, Error);
+  t.throws(function() {
+    pipe(5, 'not a function');
+  });
+
+  t.end();
+});