Fix assocPath depth bug (#17)

* Fix assocPath depth bug

* While we're here...

* Build

.travis.yml

@@ -1,10 +1,11 @@
 language: node_js
 node_js:
+  - '10'
   - '8'
   - '7'
   - '6'
 before_install:
-  - npm install -g yarn@1.6.0
+  - npm install -g yarn@1.10.0
 install:
   - yarn install --pure-lockfile
 script:

src.js

@@ -81,7 +81,7 @@ const assoc = curry((prop, val, obj) => {
 })
 
 // assocPath :: [k] -> v -> { k: v } -> { k: v }
-const assocPath = curry(([ head, ...tail ], x, obj) =>
+const assocPath = curryN(3, ([ head, ...tail ], x, obj={}) =>
   assoc(head, length(tail) ? assocPath(tail, x, obj[head]) : x, obj)
 )
 

test/assocPath.js

@@ -4,11 +4,14 @@ const { assocPath } = require('..')
 
 describe('assocPath', () => {
   it('sets a value on a path of a nested object', () =>
-    expect(assocPath(['foo', 'bar'], 'baz', {})).to.eql({ foo: { bar: 'baz' } })
+    expect(assocPath(['foo', 'bar', 'bat'], 'baz', {}))
+      .to.eql({ foo: { bar: { bat: 'baz' } } })
   )
 
   it('is curried', () => {
-    expect(assocPath(['foo', 'bar'])('baz', {})).to.eql({ foo: { bar: 'baz' } })
-    expect(assocPath(['foo', 'bar'], 'baz')({})).to.eql({ foo: { bar: 'baz' } })
+    expect(assocPath(['foo', 'bar', 'bat'])('baz', {}))
+      .to.eql({ foo: { bar: { bat: 'baz' } } })
+    expect(assocPath(['foo', 'bar', 'bat'], 'baz')({}))
+      .to.eql({ foo: { bar: { bat: 'baz' } } })
   })
 })