Refactor 1.5 OneAway logic and add more tests

Author: rroque98

JavaScript/chapter01/1.5 - OneAway/rroque98_sol.js

@@ -7,9 +7,10 @@ const isOneAway = (str1, str2) => {
   if (str1.length === str2.length) {
     let errorCount = 0;
     for (let i = 0; i < str1.length; i++) {
-      if (str1[i] !== str2[i]) {
-        errorCount++;
+      if (str1[i] === str2[i]) {
+        continue;
       }
+      errorCount++;
       if (errorCount > 1) {
         return false;
       }
@@ -18,19 +19,32 @@ const isOneAway = (str1, str2) => {
     let errorCount = 0;
     const longestStr = findLongestStr(str1, str2);
     let x = 0;
-    for(let i = 0; i < longestStr; i++) {
-      if (str1[i] !== str2[x]) {
-        errorCount++;
+    for(let i = 0; i < longestStr.length; i++) {
+      let currentChar1 = str1[i];
+      let currentChar2 = str2[x]
+      let nextChar1 = str1[i + 1];
+      let nextChar2 = str2[x + 1];
+      if (str1[i] === str2[x]) {
         x++;
+        continue;
       }
+      errorCount++;
       if (errorCount > 1) {
         return false;
       }
-      x++;
+      if (currentChar1 === nextChar2) {
+        x++;
+        i--;
+        continue;
+      } else if (currentChar2 === nextChar1) {
+        continue;
+      }
+      errorCount++;
+      return false;
     }
     // ***** Helper functions ********
     function findLongestStr(str1, str2) {
-      str1 > str2 ? str1 : str2;
+      return (str1.length > str2.length ? str1 : str2);
     }
   }
   return true;
@@ -41,3 +55,14 @@ console.log(isOneAway('pale', 'ple') === true);
 console.log(isOneAway('pales', 'pale') === true);
 console.log(isOneAway('pale', 'bale') === true);
 console.log(isOneAway('pale', 'bake') === false);
+console.log(isOneAway('paleo', 'palseo') === true);
+console.log(isOneAway('p', 'b') === true);
+console.log(isOneAway('', '') === true);
+console.log(isOneAway('p', 'p') === true);
+console.log(isOneAway('pale', 'ppalpe') === false);
+
+console.log(isOneAway('ple', 'pale') === true);
+console.log(isOneAway('pale', 'pales') === true);
+console.log(isOneAway('bale', 'pale') === true);
+console.log(isOneAway('bake', 'pale') === false);
+console.log(isOneAway('palseo', 'paleo') === true);