From 32b18eeb991781472eab6a9f69e13bcd779fc9a5 Mon Sep 17 00:00:00 2001
From: David Zukowski <zukoweb@gmail.com>
Date: Mon, 23 Jan 2017 15:27:23 -0600
Subject: [PATCH] feat(clamp): add function

---
 .eslintrc            |  2 +-
 src/bundles/index.js |  1 +
 src/clamp.js         | 18 ++++++++++++++++++
 tests/clamp.spec.js  | 23 +++++++++++++++++++++++
 4 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 src/clamp.js
 create mode 100644 tests/clamp.spec.js

diff --git a/.eslintrc b/.eslintrc
index 5655a34..f0af67d 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -107,7 +107,7 @@
     "no-whitespace-before-property": 2,
     "no-with": 2,
     "one-var": 2,
-    "operator-linebreak": [2, "after", { "overrides": { "?": "before", ":": "before" } }],
+    "operator-linebreak": [0, "after", { "overrides": { "?": "before", ":": "before" } }],
     "padded-blocks": [2, "never"],
     "quotes": [2, "single", "avoid-escape"],
     "semi": [2, "never"],
diff --git a/src/bundles/index.js b/src/bundles/index.js
index 445f273..459583d 100644
--- a/src/bundles/index.js
+++ b/src/bundles/index.js
@@ -5,6 +5,7 @@ export { default as any }         from '../any'
 export { default as append }      from '../append'
 export { default as assoc }       from '../assoc'
 export { default as chain }       from '../chain'
+export { default as clamp }       from '../clamp'
 export { default as concat }      from '../concat'
 export { default as cond }        from '../cond'
 export { default as contains }    from '../contains'
diff --git a/src/clamp.js b/src/clamp.js
new file mode 100644
index 0000000..fa9ed39
--- /dev/null
+++ b/src/clamp.js
@@ -0,0 +1,18 @@
+import _curry3 from './internal/_curry3'
+
+/**
+ * @name clamp
+ * @signature Number -> Number -> Number -> Number
+ * @since v0.18.0
+ * @description
+ * Restricts a value to a given range (inclusive).
+ * @example
+ * clamp(1, 10, 5)  // => 5
+ * clamp(1, 10, -5) // => 1
+ * clamp(1, 10, 15) // => 15
+ */
+export default _curry3(function clamp (lower, upper, value) {
+  return value < lower ? lower :
+         value > upper ? upper :
+         value
+})
diff --git a/tests/clamp.spec.js b/tests/clamp.spec.js
new file mode 100644
index 0000000..8ea9148
--- /dev/null
+++ b/tests/clamp.spec.js
@@ -0,0 +1,23 @@
+const test      = require('ava')
+    , { clamp } = require('../dist/redash')
+
+test('properly reports its arity (is ternary)', (t) => {
+  t.is(clamp.length, 3)
+})
+
+test('is curried', (t) => {
+  t.is(typeof clamp(1), 'function')
+  t.is(typeof clamp(1, 10), 'function')
+})
+
+test('restricts values to the lower bound', (t) => {
+  t.is(clamp(1, 10, -5), 1)
+})
+
+test('restricts values to the upper bound', (t) => {
+  t.is(clamp(1, 10, 15), 10)
+})
+
+test('allows values between the lower and upper bound', (t) => {
+  t.is(clamp(1, 10, 5), 5)
+})