diff --git a/tests/yarn.lock b/tests/yarn.lock
deleted file mode 100644
index 4150b26..0000000
--- a/tests/yarn.lock
+++ /dev/null
@@ -1,287 +0,0 @@
-# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
-# yarn lockfile v1
-
-
-agent-base@^4.1.0:
-  version "4.2.1"
-  resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-4.2.1.tgz#d89e5999f797875674c07d87f260fc41e83e8ca9"
-  integrity sha512-JVwXMr9nHYTUXsBFKUqhJwvlcYU/blreOEUkhNR2eXZIvwd+c+o5V4MgDPKWnMS/56awN3TRzIP+KoPn+roQtg==
-  dependencies:
-    es6-promisify "^5.0.0"
-
-async-limiter@~1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/async-limiter/-/async-limiter-1.0.0.tgz#78faed8c3d074ab81f22b4e985d79e8738f720f8"
-  integrity sha512-jp/uFnooOiO+L211eZOoSyzpOITMXx1rBITauYykG3BRYPu8h0UcxsPNB04RR5vo4Tyz3+ay17tR6JVf9qzYWg==
-
-balanced-match@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
-  integrity sha1-ibTRmasr7kneFk6gK4nORi1xt2c=
-
-brace-expansion@^1.1.7:
-  version "1.1.11"
-  resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.11.tgz#3c7fcbf529d87226f3d2f52b966ff5271eb441dd"
-  integrity sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==
-  dependencies:
-    balanced-match "^1.0.0"
-    concat-map "0.0.1"
-
-buffer-from@^1.0.0:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/buffer-from/-/buffer-from-1.1.1.tgz#32713bc028f75c02fdb710d7c7bcec1f2c6070ef"
-  integrity sha512-MQcXEUbCKtEo7bhqEs6560Hyd4XaovZlO/k9V3hjVUF/zwW7KBVdSK4gIt/bzwS9MbR5qob+F5jusZsb0YQK2A==
-
-concat-map@0.0.1:
-  version "0.0.1"
-  resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
-  integrity sha1-2Klr13/Wjfd5OnMDajug1UBdR3s=
-
-concat-stream@1.6.2:
-  version "1.6.2"
-  resolved "https://registry.yarnpkg.com/concat-stream/-/concat-stream-1.6.2.tgz#904bdf194cd3122fc675c77fc4ac3d4ff0fd1a34"
-  integrity sha512-27HBghJxjiZtIk3Ycvn/4kbJk/1uZuJFfuPEns6LaEvpvG1f0hTea8lilrouyo9mVc2GWdcEZ8OLoGmSADlrCw==
-  dependencies:
-    buffer-from "^1.0.0"
-    inherits "^2.0.3"
-    readable-stream "^2.2.2"
-    typedarray "^0.0.6"
-
-core-util-is@~1.0.0:
-  version "1.0.2"
-  resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
-  integrity sha1-tf1UIgqivFq1eqtxQMlAdUUDwac=
-
-debug@2.6.9:
-  version "2.6.9"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
-  integrity sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==
-  dependencies:
-    ms "2.0.0"
-
-debug@^3.1.0:
-  version "3.2.6"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-3.2.6.tgz#e83d17de16d8a7efb7717edbe5fb10135eee629b"
-  integrity sha512-mel+jf7nrtEl5Pn1Qx46zARXKDpBbvzezse7p7LqINmdoIk8PYP5SySaxEmYv6TZ0JyEKA1hsCId6DIhgITtWQ==
-  dependencies:
-    ms "^2.1.1"
-
-debug@^4.1.0:
-  version "4.1.1"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-4.1.1.tgz#3b72260255109c6b589cee050f1d516139664791"
-  integrity sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==
-  dependencies:
-    ms "^2.1.1"
-
-es6-promise@^4.0.3:
-  version "4.2.6"
-  resolved "https://registry.yarnpkg.com/es6-promise/-/es6-promise-4.2.6.tgz#b685edd8258886365ea62b57d30de28fadcd974f"
-  integrity sha512-aRVgGdnmW2OiySVPUC9e6m+plolMAJKjZnQlCwNSuK5yQ0JN61DZSO1X1Ufd1foqWRAlig0rhduTCHe7sVtK5Q==
-
-es6-promisify@^5.0.0:
-  version "5.0.0"
-  resolved "https://registry.yarnpkg.com/es6-promisify/-/es6-promisify-5.0.0.tgz#5109d62f3e56ea967c4b63505aef08291c8a5203"
-  integrity sha1-UQnWLz5W6pZ8S2NQWu8IKRyKUgM=
-  dependencies:
-    es6-promise "^4.0.3"
-
-extract-zip@^1.6.6:
-  version "1.6.7"
-  resolved "https://registry.yarnpkg.com/extract-zip/-/extract-zip-1.6.7.tgz#a840b4b8af6403264c8db57f4f1a74333ef81fe9"
-  integrity sha1-qEC0uK9kAyZMjbV/Txp0Mz74H+k=
-  dependencies:
-    concat-stream "1.6.2"
-    debug "2.6.9"
-    mkdirp "0.5.1"
-    yauzl "2.4.1"
-
-fd-slicer@~1.0.1:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/fd-slicer/-/fd-slicer-1.0.1.tgz#8b5bcbd9ec327c5041bf9ab023fd6750f1177e65"
-  integrity sha1-i1vL2ewyfFBBv5qwI/1nUPEXfmU=
-  dependencies:
-    pend "~1.2.0"
-
-fs.realpath@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
-  integrity sha1-FQStJSMVjKpA20onh8sBQRmU6k8=
-
-glob@^7.1.3:
-  version "7.1.3"
-  resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.3.tgz#3960832d3f1574108342dafd3a67b332c0969df1"
-  integrity sha512-vcfuiIxogLV4DlGBHIUOwI0IbrJ8HWPc4MU7HzviGeNho/UJDfi6B5p3sHeWIQ0KGIU0Jpxi5ZHxemQfLkkAwQ==
-  dependencies:
-    fs.realpath "^1.0.0"
-    inflight "^1.0.4"
-    inherits "2"
-    minimatch "^3.0.4"
-    once "^1.3.0"
-    path-is-absolute "^1.0.0"
-
-https-proxy-agent@^2.2.1:
-  version "2.2.1"
-  resolved "https://registry.yarnpkg.com/https-proxy-agent/-/https-proxy-agent-2.2.1.tgz#51552970fa04d723e04c56d04178c3f92592bbc0"
-  integrity sha512-HPCTS1LW51bcyMYbxUIOO4HEOlQ1/1qRaFWcyxvwaqUS9TY88aoEuHUY33kuAh1YhVVaDQhLZsnPd+XNARWZlQ==
-  dependencies:
-    agent-base "^4.1.0"
-    debug "^3.1.0"
-
-inflight@^1.0.4:
-  version "1.0.6"
-  resolved "https://registry.yarnpkg.com/inflight/-/inflight-1.0.6.tgz#49bd6331d7d02d0c09bc910a1075ba8165b56df9"
-  integrity sha1-Sb1jMdfQLQwJvJEKEHW6gWW1bfk=
-  dependencies:
-    once "^1.3.0"
-    wrappy "1"
-
-inherits@2, inherits@^2.0.3, inherits@~2.0.3:
-  version "2.0.3"
-  resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
-  integrity sha1-Yzwsg+PaQqUC9SRmAiSA9CCCYd4=
-
-isarray@~1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/isarray/-/isarray-1.0.0.tgz#bb935d48582cba168c06834957a54a3e07124f11"
-  integrity sha1-u5NdSFgsuhaMBoNJV6VKPgcSTxE=
-
-mime@^2.0.3:
-  version "2.4.2"
-  resolved "https://registry.yarnpkg.com/mime/-/mime-2.4.2.tgz#ce5229a5e99ffc313abac806b482c10e7ba6ac78"
-  integrity sha512-zJBfZDkwRu+j3Pdd2aHsR5GfH2jIWhmL1ZzBoc+X+3JEti2hbArWcyJ+1laC1D2/U/W1a/+Cegj0/OnEU2ybjg==
-
-minimatch@^3.0.4:
-  version "3.0.4"
-  resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.4.tgz#5166e286457f03306064be5497e8dbb0c3d32083"
-  integrity sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==
-  dependencies:
-    brace-expansion "^1.1.7"
-
-minimist@0.0.8:
-  version "0.0.8"
-  resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.8.tgz#857fcabfc3397d2625b8228262e86aa7a011b05d"
-  integrity sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0=
-
-mkdirp@0.5.1:
-  version "0.5.1"
-  resolved "https://registry.yarnpkg.com/mkdirp/-/mkdirp-0.5.1.tgz#30057438eac6cf7f8c4767f38648d6697d75c903"
-  integrity sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=
-  dependencies:
-    minimist "0.0.8"
-
-ms@2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
-  integrity sha1-VgiurfwAvmwpAd9fmGF4jeDVl8g=
-
-ms@^2.1.1:
-  version "2.1.1"
-  resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.1.tgz#30a5864eb3ebb0a66f2ebe6d727af06a09d86e0a"
-  integrity sha512-tgp+dl5cGk28utYktBsrFqA7HKgrhgPsg6Z/EfhWI4gl1Hwq8B/GmY/0oXZ6nF8hDVesS/FpnYaD/kOWhYQvyg==
-
-once@^1.3.0:
-  version "1.4.0"
-  resolved "https://registry.yarnpkg.com/once/-/once-1.4.0.tgz#583b1aa775961d4b113ac17d9c50baef9dd76bd1"
-  integrity sha1-WDsap3WWHUsROsF9nFC6753Xa9E=
-  dependencies:
-    wrappy "1"
-
-path-is-absolute@^1.0.0:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/path-is-absolute/-/path-is-absolute-1.0.1.tgz#174b9268735534ffbc7ace6bf53a5a9e1b5c5f5f"
-  integrity sha1-F0uSaHNVNP+8es5r9TpanhtcX18=
-
-pend@~1.2.0:
-  version "1.2.0"
-  resolved "https://registry.yarnpkg.com/pend/-/pend-1.2.0.tgz#7a57eb550a6783f9115331fcf4663d5c8e007a50"
-  integrity sha1-elfrVQpng/kRUzH89GY9XI4AelA=
-
-process-nextick-args@~2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/process-nextick-args/-/process-nextick-args-2.0.0.tgz#a37d732f4271b4ab1ad070d35508e8290788ffaa"
-  integrity sha512-MtEC1TqN0EU5nephaJ4rAtThHtC86dNN9qCuEhtshvpVBkAW5ZO7BASN9REnF9eoXGcRub+pFuKEpOHE+HbEMw==
-
-progress@^2.0.1:
-  version "2.0.3"
-  resolved "https://registry.yarnpkg.com/progress/-/progress-2.0.3.tgz#7e8cf8d8f5b8f239c1bc68beb4eb78567d572ef8"
-  integrity sha512-7PiHtLll5LdnKIMw100I+8xJXR5gW2QwWYkT6iJva0bXitZKa/XMrSbdmg3r2Xnaidz9Qumd0VPaMrZlF9V9sA==
-
-proxy-from-env@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/proxy-from-env/-/proxy-from-env-1.0.0.tgz#33c50398f70ea7eb96d21f7b817630a55791c7ee"
-  integrity sha1-M8UDmPcOp+uW0h97gXYwpVeRx+4=
-
-puppeteer@^1.14.0:
-  version "1.14.0"
-  resolved "https://registry.yarnpkg.com/puppeteer/-/puppeteer-1.14.0.tgz#828c1926b307200d5fc8289b99df4e13e962d339"
-  integrity sha512-SayS2wUX/8LF8Yo2Rkpc5nkAu4Jg3qu+OLTDSOZtisVQMB2Z5vjlY2TdPi/5CgZKiZroYIiyUN3sRX63El9iaw==
-  dependencies:
-    debug "^4.1.0"
-    extract-zip "^1.6.6"
-    https-proxy-agent "^2.2.1"
-    mime "^2.0.3"
-    progress "^2.0.1"
-    proxy-from-env "^1.0.0"
-    rimraf "^2.6.1"
-    ws "^6.1.0"
-
-readable-stream@^2.2.2:
-  version "2.3.6"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.3.6.tgz#b11c27d88b8ff1fbe070643cf94b0c79ae1b0aaf"
-  integrity sha512-tQtKA9WIAhBF3+VLAseyMqZeBjW0AHJoxOtYqSUZNJxauErmLbVm2FW1y+J/YA9dUrAC39ITejlZWhVIwawkKw==
-  dependencies:
-    core-util-is "~1.0.0"
-    inherits "~2.0.3"
-    isarray "~1.0.0"
-    process-nextick-args "~2.0.0"
-    safe-buffer "~5.1.1"
-    string_decoder "~1.1.1"
-    util-deprecate "~1.0.1"
-
-rimraf@^2.6.1:
-  version "2.6.3"
-  resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-2.6.3.tgz#b2d104fe0d8fb27cf9e0a1cda8262dd3833c6cab"
-  integrity sha512-mwqeW5XsA2qAejG46gYdENaxXjx9onRNCfn7L0duuP4hCuTIi/QO7PDK07KJfp1d+izWPrzEJDcSqBa0OZQriA==
-  dependencies:
-    glob "^7.1.3"
-
-safe-buffer@~5.1.0, safe-buffer@~5.1.1:
-  version "5.1.2"
-  resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.2.tgz#991ec69d296e0313747d59bdfd2b745c35f8828d"
-  integrity sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==
-
-string_decoder@~1.1.1:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.1.1.tgz#9cf1611ba62685d7030ae9e4ba34149c3af03fc8"
-  integrity sha512-n/ShnvDi6FHbbVfviro+WojiFzv+s8MPMHBczVePfUpDJLwoLT0ht1l4YwBCbi8pJAveEEdnkHyPyTP/mzRfwg==
-  dependencies:
-    safe-buffer "~5.1.0"
-
-typedarray@^0.0.6:
-  version "0.0.6"
-  resolved "https://registry.yarnpkg.com/typedarray/-/typedarray-0.0.6.tgz#867ac74e3864187b1d3d47d996a78ec5c8830777"
-  integrity sha1-hnrHTjhkGHsdPUfZlqeOxciDB3c=
-
-util-deprecate@~1.0.1:
-  version "1.0.2"
-  resolved "https://registry.yarnpkg.com/util-deprecate/-/util-deprecate-1.0.2.tgz#450d4dc9fa70de732762fbd2d4a28981419a0ccf"
-  integrity sha1-RQ1Nyfpw3nMnYvvS1KKJgUGaDM8=
-
-wrappy@1:
-  version "1.0.2"
-  resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"
-  integrity sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=
-
-ws@^6.1.0:
-  version "6.2.1"
-  resolved "https://registry.yarnpkg.com/ws/-/ws-6.2.1.tgz#442fdf0a47ed64f59b6a5d8ff130f4748ed524fb"
-  integrity sha512-GIyAXC2cB7LjvpgMt9EKS2ldqr0MTrORaleiOno6TweZ6r3TKtoFQWay/2PceJ3RuBasOHzXNn5Lrw1X0bEjqA==
-  dependencies:
-    async-limiter "~1.0.0"
-
-yauzl@2.4.1:
-  version "2.4.1"
-  resolved "https://registry.yarnpkg.com/yauzl/-/yauzl-2.4.1.tgz#9528f442dab1b2284e58b4379bb194e22e0c4005"
-  integrity sha1-lSj0QtqxsihOWLQ3m7GU4i4MQAU=
-  dependencies:
-    fd-slicer "~1.0.1"
diff --git a/web-extension/background.js b/web-extension/background.js
index 67ec302..ae0d70d 100644
--- a/web-extension/background.js
+++ b/web-extension/background.js
@@ -230,10 +230,12 @@ function prepareStyles(tab, includeStyle, appliedStyles, callback) {
 
         if (!styles) {
             callback(appliedStyles)
+            return
         }
 
         if (styles.length === 0) {
             callback(appliedStyles)
+            return
         }
 
         let allMatchingStyles = [];
@@ -258,23 +260,27 @@ function prepareStyles(tab, includeStyle, appliedStyles, callback) {
 
         if (allMatchingStyles.length === 0) {
             callback(appliedStyles)
+            return
         }
-
+    
         allMatchingStyles.sort((a, b) => b.length - a.length);
         let selStyle = allMatchingStyles[0];
 
         if (!selStyle) {
             callback(appliedStyles)
+            return
         }
 
         currentStyle = styles[selStyle.index];
 
         if (!currentStyle) {
             callback(appliedStyles)
+            return
         }
 
         if (!currentStyle.style) {
             callback(appliedStyles)
+            return
         }
 
         chrome.tabs.insertCSS(tab[0].id, { code: currentStyle.style }, () => {