diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/boo-who.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/boo-who.md
index d5964f37115..16ca6570e3d 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/boo-who.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/boo-who.md
@@ -17,61 +17,61 @@ Boolean primitives are `true` and `false`.
 `booWho(true)` should return `true`.
 
 ```js
-assert.strictEqual(booWho(true), true);
+assert.isTrue(booWho(true));
 ```
 
 `booWho(false)` should return `true`.
 
 ```js
-assert.strictEqual(booWho(false), true);
+assert.isTrue(booWho(false));
 ```
 
 `booWho([1, 2, 3])` should return `false`.
 
 ```js
-assert.strictEqual(booWho([1, 2, 3]), false);
+assert.isFalse(booWho([1, 2, 3]));
 ```
 
 `booWho([].slice)` should return `false`.
 
 ```js
-assert.strictEqual(booWho([].slice), false);
+assert.isFalse(booWho([].slice));
 ```
 
 `booWho({ "a": 1 })` should return `false`.
 
 ```js
-assert.strictEqual(booWho({ a: 1 }), false);
+assert.isFalse(booWho({ a: 1 }));
 ```
 
 `booWho(1)` should return `false`.
 
 ```js
-assert.strictEqual(booWho(1), false);
+assert.isFalse(booWho(1));
 ```
 
 `booWho(NaN)` should return `false`.
 
 ```js
-assert.strictEqual(booWho(NaN), false);
+assert.isFalse(booWho(NaN));
 ```
 
 `booWho("a")` should return `false`.
 
 ```js
-assert.strictEqual(booWho('a'), false);
+assert.isFalse(booWho('a'));
 ```
 
 `booWho("true")` should return `false`.
 
 ```js
-assert.strictEqual(booWho('true'), false);
+assert.isFalse(booWho('true'));
 ```
 
 `booWho("false")` should return `false`.
 
 ```js
-assert.strictEqual(booWho('false'), false);
+assert.isFalse(booWho('false'));
 ```
 
 # --seed--
@@ -90,7 +90,7 @@ booWho(null);
 
 ```js
 function booWho(bool) {
-  return typeof bool === "boolean";
+  return typeof bool === 'boolean';
 }
 
 booWho(null);
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/chunky-monkey.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/chunky-monkey.md
index 98b950c4ac9..017026e7785 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/chunky-monkey.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/chunky-monkey.md
@@ -90,7 +90,7 @@ function chunkArrayInGroups(arr, size) {
   return arr;
 }
 
-chunkArrayInGroups(["a", "b", "c", "d"], 2);
+chunkArrayInGroups(['a', 'b', 'c', 'd'], 2);
 ```
 
 # --solutions--
@@ -106,5 +106,5 @@ function chunkArrayInGroups(arr, size) {
   return out;
 }
 
-chunkArrayInGroups(["a", "b", "c", "d"], 2);
+chunkArrayInGroups(['a', 'b', 'c', 'd'], 2);
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/confirm-the-ending.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/confirm-the-ending.md
index b87f5fc9928..ffc28c05723 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/confirm-the-ending.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/confirm-the-ending.md
@@ -10,84 +10,85 @@ dashedName: confirm-the-ending
 
 Check if a string (first argument, `str`) ends with the given target string (second argument, `target`).
 
-This challenge *can* be solved with the `.endsWith()` method, which was introduced in ES2015. But for the purpose of this challenge, we would like you to use one of the JavaScript substring methods instead.
+This challenge _can_ be solved with the `.endsWith()` method, which was introduced in ES2015. But for the purpose of this challenge, we would like you to use one of the JavaScript substring methods instead.
 
 # --hints--
 
 `confirmEnding("Bastian", "n")` should return `true`.
 
 ```js
-assert(confirmEnding('Bastian', 'n') === true);
+assert.isTrue(confirmEnding('Bastian', 'n'));
 ```
 
 `confirmEnding("Congratulation", "on")` should return `true`.
 
 ```js
-assert(confirmEnding('Congratulation', 'on') === true);
+assert.isTrue(confirmEnding('Congratulation', 'on'));
 ```
 
 `confirmEnding("Connor", "n")` should return `false`.
 
 ```js
-assert(confirmEnding('Connor', 'n') === false);
+assert.isFalse(confirmEnding('Connor', 'n'));
 ```
 
 `confirmEnding("Walking on water and developing software from a specification are easy if both are frozen", "specification")` should return `false`.
 
 ```js
-assert(
+assert.isFalse(
   confirmEnding(
     'Walking on water and developing software from a specification are easy if both are frozen',
     'specification'
-  ) === false
+  )
 );
 ```
 
 `confirmEnding("He has to give me a new name", "name")` should return `true`.
 
 ```js
-assert(confirmEnding('He has to give me a new name', 'name') === true);
+assert.isTrue(confirmEnding('He has to give me a new name', 'name'));
 ```
 
 `confirmEnding("Open sesame", "same")` should return `true`.
 
 ```js
-assert(confirmEnding('Open sesame', 'same') === true);
+assert.isTrue(confirmEnding('Open sesame', 'same'));
 ```
 
 `confirmEnding("Open sesame", "sage")` should return `false`.
 
 ```js
-assert(confirmEnding('Open sesame', 'sage') === false);
+assert.isFalse(confirmEnding('Open sesame', 'sage'));
 ```
 
 `confirmEnding("Open sesame", "game")` should return `false`.
 
 ```js
-assert(confirmEnding('Open sesame', 'game') === false);
+assert.isFalse(confirmEnding('Open sesame', 'game'));
 ```
 
 `confirmEnding("If you want to save our world, you must hurry. We dont know how much longer we can withstand the nothing", "mountain")` should return `false`.
 
 ```js
-assert(
+assert.isFalse(
   confirmEnding(
     'If you want to save our world, you must hurry. We dont know how much longer we can withstand the nothing',
     'mountain'
-  ) === false
+  )
 );
 ```
 
 `confirmEnding("Abstraction", "action")` should return `true`.
 
 ```js
-assert(confirmEnding('Abstraction', 'action') === true);
+assert.isTrue(confirmEnding('Abstraction', 'action'));
 ```
 
 Your code should not use the built-in method `.endsWith()` to solve the challenge.
 
 ```js
-assert(!/\.endsWith\(.*?\)\s*?;?/.test(__helpers.removeJSComments(code)) && !/\['endsWith'\]/.test(__helpers.removeJSComments(code)));
+assert.notMatch(__helpers.removeJSComments(code), /\.endsWith\(.*?\)\s*?;?/);
+assert.notMatch(__helpers.removeJSComments(code), /\['endsWith'\]/);
 ```
 
 # --seed--
@@ -99,7 +100,7 @@ function confirmEnding(str, target) {
   return str;
 }
 
-confirmEnding("Bastian", "n");
+confirmEnding('Bastian', 'n');
 ```
 
 # --solutions--
@@ -109,5 +110,5 @@ function confirmEnding(str, target) {
   return str.substring(str.length - target.length) === target;
 }
 
-confirmEnding("Bastian", "n");
+confirmEnding('Bastian', 'n');
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md
index 53037b18b7d..68252f3b442 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md
@@ -17,37 +17,37 @@ You are given a variable `celsius` representing a temperature in Celsius. Use th
 `convertCtoF(0)` should return a number
 
 ```js
-assert(typeof convertCtoF(0) === 'number');
+assert.isNumber(convertCtoF(0));
 ```
 
 `convertCtoF(-30)` should return a value of `-22`
 
 ```js
-assert(convertCtoF(-30) === -22);
+assert.strictEqual(convertCtoF(-30), -22);
 ```
 
 `convertCtoF(-10)` should return a value of `14`
 
 ```js
-assert(convertCtoF(-10) === 14);
+assert.strictEqual(convertCtoF(-10), 14);
 ```
 
 `convertCtoF(0)` should return a value of `32`
 
 ```js
-assert(convertCtoF(0) === 32);
+assert.strictEqual(convertCtoF(0), 32);
 ```
 
 `convertCtoF(20)` should return a value of `68`
 
 ```js
-assert(convertCtoF(20) === 68);
+assert.strictEqual(convertCtoF(20), 68);
 ```
 
 `convertCtoF(30)` should return a value of `86`
 
 ```js
-assert(convertCtoF(30) === 86);
+assert.strictEqual(convertCtoF(30), 86);
 ```
 
 # --seed--
@@ -67,7 +67,7 @@ convertCtoF(30);
 
 ```js
 function convertCtoF(celsius) {
-  let fahrenheit = celsius * 9/5 + 32;
+  let fahrenheit = celsius * (9 / 5) + 32;
   return fahrenheit;
 }
 
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/factorialize-a-number.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/factorialize-a-number.md
index 9121612847e..9cfbcfb613b 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/factorialize-a-number.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/factorialize-a-number.md
@@ -23,31 +23,31 @@ Only integers greater than or equal to zero will be supplied to the function.
 `factorialize(5)` should return a number.
 
 ```js
-assert(typeof factorialize(5) === 'number');
+assert.isNumber(factorialize(5));
 ```
 
 `factorialize(5)` should return `120`.
 
 ```js
-assert(factorialize(5) === 120);
+assert.strictEqual(factorialize(5), 120);
 ```
 
 `factorialize(10)` should return `3628800`.
 
 ```js
-assert(factorialize(10) === 3628800);
+assert.strictEqual(factorialize(10), 3628800);
 ```
 
 `factorialize(20)` should return `2432902008176640000`.
 
 ```js
-assert(factorialize(20) === 2432902008176640000);
+assert.strictEqual(factorialize(20), 2432902008176640000);
 ```
 
 `factorialize(0)` should return `1`.
 
 ```js
-assert(factorialize(0) === 1);
+assert.strictEqual(factorialize(0), 1);
 ```
 
 # --seed--
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/falsy-bouncer.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/falsy-bouncer.md
index fb62b8eddf0..5cd15cd9f7f 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/falsy-bouncer.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/falsy-bouncer.md
@@ -45,7 +45,7 @@ You should not mutate `arr`.
 ```js
 const arr = ['a', false, 0, 'Naomi'];
 bouncer(arr);
-assert.deepEqual(arr, ['a', false, 0, 'Naomi'])
+assert.deepEqual(arr, ['a', false, 0, 'Naomi']);
 ```
 
 # --seed--
@@ -57,7 +57,7 @@ function bouncer(arr) {
   return arr;
 }
 
-bouncer([7, "ate", "", false, 9]);
+bouncer([7, 'ate', '', false, 9]);
 ```
 
 # --solutions--
@@ -67,5 +67,5 @@ function bouncer(arr) {
   return arr.filter(e => e);
 }
 
-bouncer([7, "ate", "", false, 9]);
+bouncer([7, 'ate', '', false, 9]);
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/find-the-longest-word-in-a-string.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/find-the-longest-word-in-a-string.md
index cebe978a7b2..d519d6d8abe 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/find-the-longest-word-in-a-string.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/find-the-longest-word-in-a-string.md
@@ -17,50 +17,51 @@ Your response should be a number.
 `findLongestWordLength("The quick brown fox jumped over the lazy dog")` should return a number.
 
 ```js
-assert(
-  typeof findLongestWordLength(
-    'The quick brown fox jumped over the lazy dog'
-  ) === 'number'
+assert.isNumber(
+  findLongestWordLength('The quick brown fox jumped over the lazy dog')
 );
 ```
 
 `findLongestWordLength("The quick brown fox jumped over the lazy dog")` should return `6`.
 
 ```js
-assert(
-  findLongestWordLength('The quick brown fox jumped over the lazy dog') === 6
+assert.strictEqual(
+  findLongestWordLength('The quick brown fox jumped over the lazy dog'),
+  6
 );
 ```
 
 `findLongestWordLength("May the force be with you")` should return `5`.
 
 ```js
-assert(findLongestWordLength('May the force be with you') === 5);
+assert.strictEqual(findLongestWordLength('May the force be with you'), 5);
 ```
 
 `findLongestWordLength("Google do a barrel roll")` should return `6`.
 
 ```js
-assert(findLongestWordLength('Google do a barrel roll') === 6);
+assert.strictEqual(findLongestWordLength('Google do a barrel roll'), 6);
 ```
 
 `findLongestWordLength("What is the average airspeed velocity of an unladen swallow")` should return `8`.
 
 ```js
-assert(
+assert.strictEqual(
   findLongestWordLength(
     'What is the average airspeed velocity of an unladen swallow'
-  ) === 8
+  ),
+  8
 );
 ```
 
 `findLongestWordLength("What if we try a super-long word such as otorhinolaryngology")` should return `19`.
 
 ```js
-assert(
+assert.strictEqual(
   findLongestWordLength(
     'What if we try a super-long word such as otorhinolaryngology'
-  ) === 19
+  ),
+  19
 );
 ```
 
@@ -73,7 +74,7 @@ function findLongestWordLength(str) {
   return str.length;
 }
 
-findLongestWordLength("The quick brown fox jumped over the lazy dog");
+findLongestWordLength('The quick brown fox jumped over the lazy dog');
 ```
 
 # --solutions--
@@ -83,5 +84,5 @@ function findLongestWordLength(str) {
   return str.split(' ').sort((a, b) => b.length - a.length)[0].length;
 }
 
-findLongestWordLength("The quick brown fox jumped over the lazy dog");
+findLongestWordLength('The quick brown fox jumped over the lazy dog');
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations.md
index 0a17138f1c9..6f85e48de8e 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations.md
@@ -21,73 +21,73 @@ Lastly, `["Alien", "line"]`, should return `true` because all of the letters in
 `mutation(["hello", "hey"])` should return `false`.
 
 ```js
-assert(mutation(['hello', 'hey']) === false);
+assert.isFalse(mutation(['hello', 'hey']));
 ```
 
 `mutation(["hello", "Hello"])` should return `true`.
 
 ```js
-assert(mutation(['hello', 'Hello']) === true);
+assert.isTrue(mutation(['hello', 'Hello']));
 ```
 
 `mutation(["zyxwvutsrqponmlkjihgfedcba", "qrstu"])` should return `true`.
 
 ```js
-assert(mutation(['zyxwvutsrqponmlkjihgfedcba', 'qrstu']) === true);
+assert.isTrue(mutation(['zyxwvutsrqponmlkjihgfedcba', 'qrstu']));
 ```
 
 `mutation(["Mary", "Army"])` should return `true`.
 
 ```js
-assert(mutation(['Mary', 'Army']) === true);
+assert.isTrue(mutation(['Mary', 'Army']));
 ```
 
 `mutation(["Mary", "Aarmy"])` should return `true`.
 
 ```js
-assert(mutation(['Mary', 'Aarmy']) === true);
+assert.isTrue(mutation(['Mary', 'Aarmy']));
 ```
 
 `mutation(["Alien", "line"])` should return `true`.
 
 ```js
-assert(mutation(['Alien', 'line']) === true);
+assert.isTrue(mutation(['Alien', 'line']));
 ```
 
 `mutation(["floor", "for"])` should return `true`.
 
 ```js
-assert(mutation(['floor', 'for']) === true);
+assert.isTrue(mutation(['floor', 'for']));
 ```
 
 `mutation(["hello", "neo"])` should return `false`.
 
 ```js
-assert(mutation(['hello', 'neo']) === false);
+assert.isFalse(mutation(['hello', 'neo']));
 ```
 
 `mutation(["voodoo", "no"])` should return `false`.
 
 ```js
-assert(mutation(['voodoo', 'no']) === false);
+assert.isFalse(mutation(['voodoo', 'no']));
 ```
 
 `mutation(["ate", "date"])` should return `false`.
 
 ```js
-assert(mutation(['ate', 'date']) === false);
+assert.isFalse(mutation(['ate', 'date']));
 ```
 
 `mutation(["Tiger", "Zebra"])` should return `false`.
 
 ```js
-assert(mutation(['Tiger', 'Zebra']) === false);
+assert.isFalse(mutation(['Tiger', 'Zebra']));
 ```
 
 `mutation(["Noel", "Ole"])` should return `true`.
 
 ```js
-assert(mutation(['Noel', 'Ole']) === true);
+assert.isTrue(mutation(['Noel', 'Ole']));
 ```
 
 # --seed--
@@ -99,7 +99,7 @@ function mutation(arr) {
   return arr;
 }
 
-mutation(["hello", "hey"]);
+mutation(['hello', 'hey']);
 ```
 
 # --solutions--
@@ -108,10 +108,16 @@ mutation(["hello", "hey"]);
 function mutation(arr) {
   let hash = Object.create(null);
 
-  arr[0].toLowerCase().split('').forEach(c => hash[c] = true);
+  arr[0]
+    .toLowerCase()
+    .split('')
+    .forEach(c => (hash[c] = true));
 
-  return !arr[1].toLowerCase().split('').filter(c => !hash[c]).length;
+  return !arr[1]
+    .toLowerCase()
+    .split('')
+    .filter(c => !hash[c]).length;
 }
 
-mutation(["hello", "hey"]);
+mutation(['hello', 'hey']);
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/repeat-a-string-repeat-a-string.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/repeat-a-string-repeat-a-string.md
index dbae3dde019..a662ed389e4 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/repeat-a-string-repeat-a-string.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/repeat-a-string-repeat-a-string.md
@@ -8,56 +8,56 @@ dashedName: repeat-a-string-repeat-a-string
 
 # --description--
 
-Repeat a given string `str` (first argument) for `num` times (second argument). Return an empty string if `num` is not a positive number. For the purpose of this challenge, do *not* use the built-in `.repeat()` method.
+Repeat a given string `str` (first argument) for `num` times (second argument). Return an empty string if `num` is not a positive number. For the purpose of this challenge, do _not_ use the built-in `.repeat()` method.
 
 # --hints--
 
 `repeatStringNumTimes("*", 3)` should return the string `***`.
 
 ```js
-assert(repeatStringNumTimes('*', 3) === '***');
+assert.strictEqual(repeatStringNumTimes('*', 3), '***');
 ```
 
 `repeatStringNumTimes("abc", 3)` should return the string `abcabcabc`.
 
 ```js
-assert(repeatStringNumTimes('abc', 3) === 'abcabcabc');
+assert.strictEqual(repeatStringNumTimes('abc', 3), 'abcabcabc');
 ```
 
 `repeatStringNumTimes("abc", 4)` should return the string `abcabcabcabc`.
 
 ```js
-assert(repeatStringNumTimes('abc', 4) === 'abcabcabcabc');
+assert.strictEqual(repeatStringNumTimes('abc', 4), 'abcabcabcabc');
 ```
 
 `repeatStringNumTimes("abc", 1)` should return the string `abc`.
 
 ```js
-assert(repeatStringNumTimes('abc', 1) === 'abc');
+assert.strictEqual(repeatStringNumTimes('abc', 1), 'abc');
 ```
 
 `repeatStringNumTimes("*", 8)` should return the string `********`.
 
 ```js
-assert(repeatStringNumTimes('*', 8) === '********');
+assert.strictEqual(repeatStringNumTimes('*', 8), '********');
 ```
 
 `repeatStringNumTimes("abc", -2)` should return an empty string (`""`).
 
 ```js
-assert(repeatStringNumTimes('abc', -2) === '');
+assert.isEmpty(repeatStringNumTimes('abc', -2));
 ```
 
 The built-in `repeat()` method should not be used.
 
 ```js
-assert(!/\.repeat/g.test(__helpers.removeJSComments(code)));
+assert.notMatch(__helpers.removeJSComments(code), /\.repeat/g);
 ```
 
 `repeatStringNumTimes("abc", 0)` should return `""`.
 
 ```js
-assert(repeatStringNumTimes('abc', 0) === '');
+assert.isEmpty(repeatStringNumTimes('abc', 0));
 ```
 
 # --seed--
@@ -69,7 +69,7 @@ function repeatStringNumTimes(str, num) {
   return str;
 }
 
-repeatStringNumTimes("abc", 3);
+repeatStringNumTimes('abc', 3);
 ```
 
 # --solutions--
@@ -77,8 +77,8 @@ repeatStringNumTimes("abc", 3);
 ```js
 function repeatStringNumTimes(str, num) {
   if (num < 1) return '';
-  return num === 1 ? str : str + repeatStringNumTimes(str, num-1);
+  return num === 1 ? str : str + repeatStringNumTimes(str, num - 1);
 }
 
-repeatStringNumTimes("abc", 3);
+repeatStringNumTimes('abc', 3);
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/return-largest-numbers-in-arrays.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/return-largest-numbers-in-arrays.md
index 7f8b6a84a2b..c783628ede9 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/return-largest-numbers-in-arrays.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/return-largest-numbers-in-arrays.md
@@ -17,13 +17,13 @@ Remember, you can iterate through an array with a simple for loop, and access ea
 `largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]])` should return an array.
 
 ```js
-assert(
+assert.isArray(
   largestOfFour([
     [4, 5, 1, 3],
     [13, 27, 18, 26],
     [32, 35, 37, 39],
     [1000, 1001, 857, 1]
-  ]).constructor === Array
+  ])
 );
 ```
 
@@ -78,7 +78,12 @@ function largestOfFour(arr) {
   return arr;
 }
 
-largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);
+largestOfFour([
+  [4, 5, 1, 3],
+  [13, 27, 18, 26],
+  [32, 35, 37, 39],
+  [1000, 1001, 857, 1]
+]);
 ```
 
 # --solutions--
@@ -88,5 +93,10 @@ function largestOfFour(arr) {
   return arr.map(subArr => Math.max.apply(null, subArr));
 }
 
-largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);
+largestOfFour([
+  [4, 5, 1, 3],
+  [13, 27, 18, 26],
+  [32, 35, 37, 39],
+  [1000, 1001, 857, 1]
+]);
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/reverse-a-string.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/reverse-a-string.md
index bca8cb7bd6f..3f08a358bb2 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/reverse-a-string.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/reverse-a-string.md
@@ -17,25 +17,28 @@ For example, `"hello"` should become `"olleh"`.
 `reverseString("hello")` should return a string.
 
 ```js
-assert(typeof reverseString('hello') === 'string');
+assert.isString(reverseString('hello'));
 ```
 
 `reverseString("hello")` should return the string `olleh`.
 
 ```js
-assert(reverseString('hello') === 'olleh');
+assert.strictEqual(reverseString('hello'), 'olleh');
 ```
 
 `reverseString("Howdy")` should return the string `ydwoH`.
 
 ```js
-assert(reverseString('Howdy') === 'ydwoH');
+assert.strictEqual(reverseString('Howdy'), 'ydwoH');
 ```
 
 `reverseString("Greetings from Earth")` should return the string `htraE morf sgniteerG`.
 
 ```js
-assert(reverseString('Greetings from Earth') === 'htraE morf sgniteerG');
+assert.strictEqual(
+  reverseString('Greetings from Earth'),
+  'htraE morf sgniteerG'
+);
 ```
 
 # --seed--
@@ -47,7 +50,7 @@ function reverseString(str) {
   return str;
 }
 
-reverseString("hello");
+reverseString('hello');
 ```
 
 # --solutions--
@@ -57,5 +60,5 @@ function reverseString(str) {
   return str.split('').reverse().join('');
 }
 
-reverseString("hello");
+reverseString('hello');
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/slice-and-splice.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/slice-and-splice.md
index f336149eae4..541ed583ab0 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/slice-and-splice.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/slice-and-splice.md
@@ -69,7 +69,7 @@ assert.deepEqual(testArr2, ['a', 'b']);
 
 ```js
 let testArr1 = [1, 2];
-let testArr2 = ["a", "b"];
+let testArr2 = ['a', 'b'];
 ```
 
 ## --seed-contents--
@@ -89,7 +89,7 @@ function frankenSplice(arr1, arr2, n) {
   // It's alive. It's alive!
   let result = arr2.slice();
   for (let i = 0; i < arr1.length; i++) {
-    result.splice(n+i, 0, arr1[i]);
+    result.splice(n + i, 0, arr1[i]);
   }
   return result;
 }
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/title-case-a-sentence.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/title-case-a-sentence.md
index 7df738eaa0f..c57497dfcdd 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/title-case-a-sentence.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/title-case-a-sentence.md
@@ -17,27 +17,27 @@ For the purpose of this exercise, you should also capitalize connecting words li
 `titleCase("I'm a little tea pot")` should return a string.
 
 ```js
-assert(typeof titleCase("I'm a little tea pot") === 'string');
+assert.isString(titleCase("I'm a little tea pot"));
 ```
 
 `titleCase("I'm a little tea pot")` should return the string `I'm A Little Tea Pot`.
 
 ```js
-assert(titleCase("I'm a little tea pot") === "I'm A Little Tea Pot");
+assert.strictEqual(titleCase("I'm a little tea pot"), "I'm A Little Tea Pot");
 ```
 
 `titleCase("sHoRt AnD sToUt")` should return the string `Short And Stout`.
 
 ```js
-assert(titleCase('sHoRt AnD sToUt') === 'Short And Stout');
+assert.strictEqual(titleCase('sHoRt AnD sToUt'), 'Short And Stout');
 ```
 
 `titleCase("HERE IS MY HANDLE HERE IS MY SPOUT")` should return the string `Here Is My Handle Here Is My Spout`.
 
 ```js
-assert(
-  titleCase('HERE IS MY HANDLE HERE IS MY SPOUT') ===
-    'Here Is My Handle Here Is My Spout'
+assert.strictEqual(
+  titleCase('HERE IS MY HANDLE HERE IS MY SPOUT'),
+  'Here Is My Handle Here Is My Spout'
 );
 ```
 
@@ -57,7 +57,10 @@ titleCase("I'm a little tea pot");
 
 ```js
 function titleCase(str) {
-  return str.split(' ').map(word => word.charAt(0).toUpperCase() + word.substring(1).toLowerCase()).join(' ');
+  return str
+    .split(' ')
+    .map(word => word.charAt(0).toUpperCase() + word.substring(1).toLowerCase())
+    .join(' ');
 }
 
 titleCase("I'm a little tea pot");
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/truncate-a-string.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/truncate-a-string.md
index 855fe031441..4a16763762f 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/truncate-a-string.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/truncate-a-string.md
@@ -15,53 +15,55 @@ Truncate a string (first argument) if it is longer than the given maximum string
 `truncateString("A-tisket a-tasket A green and yellow basket", 8)` should return the string `A-tisket...`.
 
 ```js
-assert(
-  truncateString('A-tisket a-tasket A green and yellow basket', 8) ===
-    'A-tisket...'
+assert.strictEqual(
+  truncateString('A-tisket a-tasket A green and yellow basket', 8),
+  'A-tisket...'
 );
 ```
 
 `truncateString("Peter Piper picked a peck of pickled peppers", 11)` should return the string `Peter Piper...`.
 
 ```js
-assert(
-  truncateString('Peter Piper picked a peck of pickled peppers', 11) ===
-    'Peter Piper...'
+assert.strictEqual(
+  truncateString('Peter Piper picked a peck of pickled peppers', 11),
+  'Peter Piper...'
 );
 ```
 
 `truncateString("A-tisket a-tasket A green and yellow basket", "A-tisket a-tasket A green and yellow basket".length)` should return the string `A-tisket a-tasket A green and yellow basket`.
 
 ```js
-assert(
+assert.strictEqual(
   truncateString(
     'A-tisket a-tasket A green and yellow basket',
     'A-tisket a-tasket A green and yellow basket'.length
-  ) === 'A-tisket a-tasket A green and yellow basket'
+  ),
+  'A-tisket a-tasket A green and yellow basket'
 );
 ```
 
 `truncateString("A-tisket a-tasket A green and yellow basket", "A-tisket a-tasket A green and yellow basket".length + 2)` should return the string `A-tisket a-tasket A green and yellow basket`.
 
 ```js
-assert(
+assert.strictEqual(
   truncateString(
     'A-tisket a-tasket A green and yellow basket',
     'A-tisket a-tasket A green and yellow basket'.length + 2
-  ) === 'A-tisket a-tasket A green and yellow basket'
+  ),
+  'A-tisket a-tasket A green and yellow basket'
 );
 ```
 
 `truncateString("A-", 1)` should return the string `A...`.
 
 ```js
-assert(truncateString('A-', 1) === 'A...');
+assert.strictEqual(truncateString('A-', 1), 'A...');
 ```
 
 `truncateString("Absolutely Longer", 2)` should return the string `Ab...`.
 
 ```js
-assert(truncateString('Absolutely Longer', 2) === 'Ab...');
+assert.strictEqual(truncateString('Absolutely Longer', 2), 'Ab...');
 ```
 
 # --seed--
@@ -73,7 +75,7 @@ function truncateString(str, num) {
   return str;
 }
 
-truncateString("A-tisket a-tasket A green and yellow basket", 8);
+truncateString('A-tisket a-tasket A green and yellow basket', 8);
 ```
 
 # --solutions--
@@ -87,5 +89,5 @@ function truncateString(str, num) {
   return str.slice(0, num) + '...';
 }
 
-truncateString("A-tisket a-tasket A green and yellow basket", 8);
+truncateString('A-tisket a-tasket A green and yellow basket', 8);
 ```
diff --git a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/where-do-i-belong.md b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/where-do-i-belong.md
index 9d324337924..565d71b5681 100644
--- a/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/where-do-i-belong.md
+++ b/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/where-do-i-belong.md
@@ -16,100 +16,100 @@ Likewise, `getIndexToIns([20,3,5], 19)` should return `2` because once the array
 
 # --hints--
 
-`getIndexToIns([10, 20, 30, 40, 50], 35)` should return `3`.
-
-```js
-assert(getIndexToIns([10, 20, 30, 40, 50], 35) === 3);
-```
-
 `getIndexToIns([10, 20, 30, 40, 50], 35)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([10, 20, 30, 40, 50], 35) === 'number');
+assert.isNumber(getIndexToIns([10, 20, 30, 40, 50], 35));
 ```
 
-`getIndexToIns([10, 20, 30, 40, 50], 30)` should return `2`.
+`getIndexToIns([10, 20, 30, 40, 50], 35)` should return `3`.
 
 ```js
-assert(getIndexToIns([10, 20, 30, 40, 50], 30) === 2);
+assert.strictEqual(getIndexToIns([10, 20, 30, 40, 50], 35), 3);
 ```
 
 `getIndexToIns([10, 20, 30, 40, 50], 30)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([10, 20, 30, 40, 50], 30) === 'number');
+assert.isNumber(getIndexToIns([10, 20, 30, 40, 50], 30));
 ```
 
-`getIndexToIns([40, 60], 50)` should return `1`.
+`getIndexToIns([10, 20, 30, 40, 50], 30)` should return `2`.
 
 ```js
-assert(getIndexToIns([40, 60], 50) === 1);
+assert.strictEqual(getIndexToIns([10, 20, 30, 40, 50], 30), 2);
 ```
 
 `getIndexToIns([40, 60], 50)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([40, 60], 50) === 'number');
+assert.isNumber(getIndexToIns([40, 60], 50));
 ```
 
-`getIndexToIns([3, 10, 5], 3)` should return `0`.
+`getIndexToIns([40, 60], 50)` should return `1`.
 
 ```js
-assert(getIndexToIns([3, 10, 5], 3) === 0);
+assert.strictEqual(getIndexToIns([40, 60], 50), 1);
 ```
 
 `getIndexToIns([3, 10, 5], 3)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([3, 10, 5], 3) === 'number');
+assert.isNumber(getIndexToIns([3, 10, 5], 3));
 ```
 
-`getIndexToIns([5, 3, 20, 3], 5)` should return `2`.
+`getIndexToIns([3, 10, 5], 3)` should return `0`.
 
 ```js
-assert(getIndexToIns([5, 3, 20, 3], 5) === 2);
+assert.strictEqual(getIndexToIns([3, 10, 5], 3), 0);
 ```
 
 `getIndexToIns([5, 3, 20, 3], 5)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([5, 3, 20, 3], 5) === 'number');
+assert.isNumber(getIndexToIns([5, 3, 20, 3], 5));
+```
+
+`getIndexToIns([5, 3, 20, 3], 5)` should return `2`.
+
+```js
+assert.strictEqual(getIndexToIns([5, 3, 20, 3], 5), 2);
 ```
 
 `getIndexToIns([2, 20, 10], 19)` should return `2`.
 
 ```js
-assert(getIndexToIns([2, 20, 10], 19) === 2);
+assert.strictEqual(getIndexToIns([2, 20, 10], 19), 2);
 ```
 
 `getIndexToIns([2, 20, 10], 19)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([2, 20, 10], 19) === 'number');
+assert.isNumber(getIndexToIns([2, 20, 10], 19));
 ```
 
 `getIndexToIns([2, 5, 10], 15)` should return `3`.
 
 ```js
-assert(getIndexToIns([2, 5, 10], 15) === 3);
+assert.strictEqual(getIndexToIns([2, 5, 10], 15), 3);
 ```
 
 `getIndexToIns([2, 5, 10], 15)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([2, 5, 10], 15) === 'number');
-```
-
-`getIndexToIns([], 1)` should return `0`.
-
-```js
-assert(getIndexToIns([], 1) === 0);
+assert.isNumber(getIndexToIns([2, 5, 10], 15));
 ```
 
 `getIndexToIns([], 1)` should return a number.
 
 ```js
-assert(typeof getIndexToIns([], 1) === 'number');
+assert.isNumber(getIndexToIns([], 1));
+```
+
+`getIndexToIns([], 1)` should return `0`.
+
+```js
+assert.strictEqual(getIndexToIns([], 1), 0);
 ```
 
 # --seed--