update and lock deps, fix lint, generalize seq to reduceAsync and move it from hard => intermediate

Author: bcherny

.eslintrc.js

@@ -5,6 +5,9 @@ module.exports = {
     "promise"
   ],
   "rules": {
-    "import/first": false
+    "import/first": [0],
+    "new-parens": [0],
+    "padded-blocks": [0],
+    "space-before-function-paren": [0]
   }
 }

coding-harder/seq.js

@@ -27,4 +27,4 @@ import { test } from 'ava'
 test(t => t.deepEqual(assignDeep({ a: 1 }, {}), { a: 1 }))
 test(t => t.deepEqual(assignDeep({ a: 1 }, { a: 2 }), { a: 2 }))
 test(t => t.deepEqual(assignDeep({ a: 1 }, { a: { b: 2 } }), { a: { b: 2 } }))
-test(t => t.deepEqual(assignDeep({ a: { b: { c: 1 }}}, { a: { b: { d: 2 }}, e: 3 }), { a: { b: { c: 1, d: 2 }}, e: 3 }))
+test(t => t.deepEqual(assignDeep({ a: { b: { c: 1 } } }, { a: { b: { d: 2 } }, e: 3 }), { a: { b: { c: 1, d: 2 } }, e: 3 }))

coding-intermediate/assignDeep.js

@@ -0,0 +1,27 @@
+/// solution
+
+let reduceAsync = async (as, fn, init) => {
+  for (let a of as) {
+    init = fn(init, await a())
+  }
+  return init
+}
+
+/// tests
+
+import { test } from 'ava'
+
+test(async t => {
+  let a = () => Promise.resolve('a')
+  let b = () => Promise.resolve('b')
+  let c = () => Promise.resolve('c')
+
+  t.deepEqual(
+    await reduceAsync([a, b, c], (acc, value) => [...acc, value], []),
+    ['a', 'b', 'c']
+  )
+  t.deepEqual(
+    await reduceAsync([a, c, b], (acc, value) => [...acc, value], ['d']),
+    ['d', 'a', 'c', 'b']
+  )
+})