adding similarity check (#29)

* adding similarity check

* adding paging

* fixing tests

* docu

* better error handling

* fixing tests

* adjusting page limit

* fixing login screen

* cleanup

* upgrade browser list

* prevent spamming the log

* fixing tests

* removing job listings when removing a job or the user

.eslintrc.js

@@ -4,6 +4,7 @@ module.exports = {
     es6: true,
     node: true,
     browser: true,
+    mocha: true,
   },
   parser: 'babel-eslint',
   extends: ['eslint:recommended', 'prettier'],
@@ -11,6 +12,7 @@ module.exports = {
   globals: {
     Promise: false,
     describe: true,
+    after: true,
     it: true,
     fetch: true,
   },

CHANGELOG.md

@@ -1,8 +1,13 @@
+###### [V5.2.0]
+- Upgrading dependencies
+- Adding new similarity check layer (Duplicates are being removed now)
+- Adding paging for search results
+
 ###### [V5.1.0]
 - Upgrading dependencies
 - NodeJS 12.13 is now the minimum supported version
 - Adding general settings as new configuration page to ui
-- Adding new feature working hours 
+- Adding new feature working hours
 
 ###### [V5.0.0]
 - Upgrading dependencies

conf/config.json

@@ -1 +1 @@
-{"interval":"30","port":9998,"scrapingAnt":{"apiKey":""},"workingHours":{"from":"","to":""}}
+{"interval":"60","port":9998,"scrapingAnt":{"apiKey":""},"workingHours":{"from":"","to":""}}

index.js

@@ -9,8 +9,9 @@ const path = './lib/provider';
 const provider = fs.readdirSync(path).filter((file) => file.endsWith('.js'));
 const config = require('./conf/config.json');
 
-const jobStorage = require('./lib/services/storage/jobStorage');
+const similarityCache = require('./lib/services/similarity-check/similarityCache');
 const { setLastJobExecution } = require('./lib/services/storage/listingsStorage');
+const jobStorage = require('./lib/services/storage/jobStorage');
 const FredyRuntime = require('./lib/FredyRuntime');
 
 const { duringWorkingHoursOrNotSet } = require('./lib/utils');
@@ -50,7 +51,13 @@ setInterval(
                 throw new Error(`Provider Config for provider with id ${providerId} not found.`);
               }
               pro.init(providerConfig, job.blacklist);
-              await new FredyRuntime(pro.config, job.notificationAdapter, providerId, job.id).execute();
+              await new FredyRuntime(
+                pro.config,
+                job.notificationAdapter,
+                providerId,
+                job.id,
+                similarityCache
+              ).execute();
               setLastJobExecution(job.id);
             });
         });

lib/FredyRuntime.js

@@ -1,4 +1,4 @@
-const { NoNewListingsError } = require('./errors');
+const { NoNewListingsWarning } = require('./errors');
 const { setKnownListings, getKnownListings } = require('./services/storage/listingsStorage');
 
 const notify = require('./notification/notify');
@@ -12,12 +12,14 @@ class FredyRuntime {
    * @param notificationConfig the config for all notifications
    * @param providerId the id of the provider currently in use
    * @param jobKey key of the job that is currently running (from within the config)
+   * @param similarityCache cache instance holding values to check for similarity of entries
    */
-  constructor(providerConfig, notificationConfig, providerId, jobKey) {
+  constructor(providerConfig, notificationConfig, providerId, jobKey, similarityCache) {
     this._providerConfig = providerConfig;
     this._notificationConfig = notificationConfig;
     this._providerId = providerId;
     this._jobKey = jobKey;
+    this._similarityCache = similarityCache;
   }
 
   execute() {
@@ -33,6 +35,8 @@ class FredyRuntime {
         .then(this._findNew.bind(this))
         //store everything in db
         .then(this._save.bind(this))
+        //check for similar listings. if found, remove them before notifying
+        .then(this._filterBySimilarListings.bind(this))
         //notify the user using the configured notification adapter
         .then(this._notify.bind(this))
         //if an error occurred on the way, handle it here.
@@ -53,14 +57,29 @@ class FredyRuntime {
       }
       const u = scrapingAnt.isImmoscout(id) ? scrapingAnt.transformUrlForScrapingAnt(url, id) : url;
       try {
-        xray(u, this._providerConfig.crawlContainer, [this._providerConfig.crawlFields])
+        if (this._providerConfig.paginate != null) {
-          .then((listings) => {
+          xray(u, this._providerConfig.crawlContainer, [this._providerConfig.crawlFields])
-            resolve(listings == null ? [] : listings);
+            //the first 2 pages should be enough here
-          })
+            //TODO: Think about automagically sort by date
-          .catch((err) => {
+            .limit(2)
-            reject(err);
+            .paginate(this._providerConfig.paginate)
-            console.error(err);
+            .then((listings) => {
-          });
+              resolve(listings == null ? [] : listings);
+            })
+            .catch((err) => {
+              reject(err);
+              console.error(err);
+            });
+        } else {
+          xray(u, this._providerConfig.crawlContainer, [this._providerConfig.crawlFields])
+            .then((listings) => {
+              resolve(listings == null ? [] : listings);
+            })
+            .catch((err) => {
+              reject(err);
+              console.error(err);
+            });
+        }
       } catch (error) {
         reject(error);
         console.error(error);
@@ -80,7 +99,7 @@ class FredyRuntime {
     const newListings = listings.filter((o) => getKnownListings(this._jobKey, this._providerId)[o.id] == null);
 
     if (newListings.length === 0) {
-      throw new NoNewListingsError();
+      throw new NoNewListingsWarning();
     }
 
     return newListings;
@@ -100,8 +119,22 @@ class FredyRuntime {
     return newListings;
   }
 
+  _filterBySimilarListings(listings) {
+    const filteredList = listings.filter((listing) => {
+      const similar = this._similarityCache.hasSimilarEntries(this._jobKey, listing.title);
+      if (similar) {
+        /* eslint-disable no-console */
+        console.debug(`Filtering similar entry for job with id ${this._jobKey} with title: `, listing.title);
+        /* eslint-enable no-console */
+      }
+      return !similar;
+    });
+    filteredList.forEach((filter) => this._similarityCache.addCacheEntry(this._jobKey, filter.title));
+    return filteredList;
+  }
+
   _handleError(err) {
-    if (err.name !== 'NoNewListingsError') console.error(err);
+    if (err.name !== 'NoNewListingsWarning') console.error(err);
   }
 }
 

lib/errors.js

@@ -10,6 +10,6 @@ class ExtendableError extends Error {
   }
 }
 
-class NoNewListingsError extends ExtendableError {}
+class NoNewListingsWarning extends ExtendableError {}
 
-module.exports = { NoNewListingsError };
+module.exports = { NoNewListingsWarning };

lib/provider/einsAImmobilien.js

@@ -30,7 +30,6 @@ const config = {
     title: '.tabelle .inner_object_data .tabelle_inhalt_titel_black | removeNewline | trim',
     description: '.tabelle .inner_object_data .objekt_beschreibung | removeNewline | trim',
   },
-  paginate: '.pagination_blocks div:last a@href',
   normalize: normalize,
   filter: applyBlacklist,
 };

lib/provider/kleinanzeigen.js

@@ -20,7 +20,7 @@ function applyBlacklist(o) {
 
 const config = {
   url: null,
-  crawlContainer: '#srchrslt-adtable .ad-listitem',
+  crawlContainer: '#srchrslt-adtable .ad-listitem ',
   crawlFields: {
     id: '.aditem@data-adid | int',
     price: '.aditem-main--middle--price | removeNewline | trim',

lib/provider/wgGesucht.js

@@ -24,7 +24,6 @@ const config = {
     title: '.truncate_title a |removeNewline |trim',
     link: '.truncate_title a@href',
   },
-  paginate: '.pagination-sm:first a:last@href',
   normalize: normalize,
   filter: applyBlacklist,
 };

lib/services/similarity-check/SimilarityCacheEntry.js

@@ -0,0 +1,36 @@
+const stringSimilarity = require('string-similarity');
+
+//if the score is higher than this, it will be considered a match
+const MAX_DICE_INDEX = 0.7;
+
+/**
+ * The similarity check is based on the dice coefficient. => https://en.wikipedia.org/wiki/S%C3%B8rensen%E2%80%93Dice_coefficient
+ *
+ * @type {module.SimilarityCacheEntry}
+ */
+module.exports = class SimilarityCacheEntry {
+  constructor(time) {
+    this.time = time;
+    this.values = [];
+  }
+
+  setCacheEntry = (entry) => {
+    this.values.push(entry);
+  };
+
+  getTime = () => {
+    return this.time;
+  };
+
+  hasSimilarEntries = (value) => {
+    if (this.values.length > 0) {
+      for (let i = 0; i < this.values.length; i++) {
+        const index = stringSimilarity.compareTwoStrings(value, this.values[i]);
+        if (index >= MAX_DICE_INDEX) {
+          return true;
+        }
+      }
+    }
+    return false;
+  };
+};

lib/services/similarity-check/similarityCache.js

@@ -0,0 +1,63 @@
+/**
+ * each job that runs scrapes all provider. This cache holds the titles of the found listing(s) and provides
+ * a similarity check. if this check returns true, it will not be forwarded to the notification adapter, thus
+ * the user won't see any duplicates
+ *
+ * The retention of this cache is per default 5 minutes, but can be smaller if the interval is > 5 mins.
+ *
+ * @type {module.SimilarityCacheEntry|{}}
+ */
+const SimilarityCacheEntry = require('./SimilarityCacheEntry');
+const config = require('../../../conf/config.json');
+
+//5 minutes
+let retention = 5 * 60 * 1000;
+
+const intervalInMs = config.interval * 60 * 1000;
+//an interval below 5 mins sounds crazy, but there are ppl out there doing crazy shit.
+if (intervalInMs <= retention) {
+  retention = Math.floor(intervalInMs / 2);
+}
+
+//jobid -> SimilarityCacheEntry
+const cache = {};
+
+let intervalId;
+
+exports.addCacheEntry = (jobId, value) => {
+  cache[jobId] = cache[jobId] || new SimilarityCacheEntry(Date.now());
+  cache[jobId].setCacheEntry(value);
+};
+
+exports.hasSimilarEntries = (jobId, value) => {
+  if (cache[jobId] == null) {
+    return false;
+  }
+
+  return cache[jobId].hasSimilarEntries(value);
+};
+
+/**
+ * cleanup
+ */
+intervalId = setInterval(() => {
+  const keysToBeRemoved = [];
+  const now = Date.now();
+
+  Object.keys(cache).forEach((key) => {
+    if (cache[key].getTime() + retention < now) {
+      keysToBeRemoved.push(key);
+    }
+  });
+
+  if (keysToBeRemoved.length > 0) {
+    keysToBeRemoved.forEach((key) => delete cache[key]);
+  }
+}, 10000);
+
+/**
+ * mostly used for tests
+ */
+exports.stopCacheCleanup = () => {
+  clearInterval(intervalId);
+};

lib/services/storage/jobStorage.js

@@ -61,12 +61,18 @@ exports.setJobStatus = ({ jobId, status }) => {
 };
 
 exports.removeJob = (jobId) => {
+  listingStorage.removeListings(jobId);
   db.get('jobs')
     .remove((job) => job.id === jobId)
     .write();
 };
 
 exports.removeJobsByUserId = (userId) => {
+  db.get('jobs')
+    .value()
+    .filter((job) => job.userId === userId)
+    .forEach((job) => listingStorage.removeListings(job.id));
+
   db.get('jobs')
     .remove((job) => job.userId === userId)
     .write();

lib/services/storage/listingsStorage.js

@@ -47,3 +47,7 @@ exports.setLastJobExecution = (jobId) => {
   const key = buildKey(jobId, null, 'lastExecution');
   return db.set(key, Date.now()).write();
 };
+
+exports.removeListings = (jobId) => {
+  db.unset(jobId).write();
+};

package.json

@@ -1,6 +1,6 @@
 {
   "name": "fredy",
-  "version": "5.1.0",
+  "version": "5.2.0",
   "description": "[F]ind [R]eal [E]states [d]amn eas[y].",
   "scripts": {
     "start": "node index.js",
@@ -53,12 +53,12 @@
   "dependencies": {
     "@rematch/core": "2.0.1",
     "@rematch/loading": "2.0.1",
-    "@sendgrid/mail": "7.4.4",
+    "@sendgrid/mail": "7.4.5",
     "axios": "0.21.1",
     "body-parser": "1.19.0",
     "cookie-session": "1.4.0",
     "handlebars": "4.7.7",
-    "highcharts": "9.1.0",
+    "highcharts": "9.1.2",
     "highcharts-react-official": "3.0.0",
     "lowdb": "1.0.0",
     "markdown": "^0.5.0",
@@ -76,36 +76,37 @@
     "semantic-ui-react": "2.0.3",
     "serve-static": "^1.14.1",
     "slack": "11.0.2",
+    "string-similarity": "^4.0.4",
     "x-ray": "2.3.4"
   },
   "devDependencies": {
-    "@babel/core": "7.14.3",
+    "@babel/core": "7.14.6",
-    "@babel/preset-env": "7.14.2",
+    "@babel/preset-env": "7.14.7",
-    "@babel/preset-react": "7.13.13",
+    "@babel/preset-react": "7.14.5",
     "babel-eslint": "10.1.0",
     "babel-loader": "8.2.2",
     "chai": "4.3.4",
     "clean-webpack-plugin": "3.0.0",
-    "copy-webpack-plugin": "9.0.0",
+    "copy-webpack-plugin": "9.0.1",
     "css-loader": "5.2.6",
-    "eslint": "7.27.0",
+    "eslint": "7.29.0",
     "eslint-config-prettier": "8.3.0",
-    "eslint-plugin-react": "7.23.2",
+    "eslint-plugin-react": "7.24.0",
     "file-loader": "6.2.0",
     "history": "5.0.0",
     "husky": "4.3.8",
     "less": "4.1.1",
-    "less-loader": "9.0.0",
+    "less-loader": "10.0.0",
     "lint-staged": "11.0.0",
-    "mocha": "8.4.0",
+    "mocha": "9.0.1",
-    "prettier": "2.3.0",
+    "prettier": "2.3.2",
     "proxyquire": "2.1.3",
     "redux-logger": "3.0.6",
-    "style-loader": "2.0.0",
+    "style-loader": "3.0.0",
     "url-loader": "4.1.1",
-    "webpack": "5.37.1",
+    "webpack": "5.40.0",
     "webpack-cli": "3.3.12",
     "webpack-dev-server": "3.11.2",
-    "webpack-merge": "5.7.3"
+    "webpack-merge": "5.8.0"
   }
 }

test/provider/einsAImmobilien.test.js

@@ -1,3 +1,4 @@
+const similarityCache = require('../../lib/services/similarity-check/similarityCache');
 const mockNotification = require('../mocks/mockNotification');
 const providerConfig = require('./testProvider.json');
 const mockStore = require('../mocks/mockStore');
@@ -6,6 +7,10 @@ const expect = require('chai').expect;
 const provider = require('../../lib/provider/einsAImmobilien');
 
 describe('#einsAImmobilien testsuite()', () => {
+  after(() => {
+    similarityCache.stopCacheCleanup();
+  });
+
   provider.init(providerConfig.einsAImmobilien, [], []);
 
   const Fredy = proxyquire('../../lib/FredyRuntime', {
@@ -17,7 +22,7 @@ describe('#einsAImmobilien testsuite()', () => {
 
   it('should test einsAImmobilien provider', async () => {
     return await new Promise((resolve) => {
-      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1');
+      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1', similarityCache);
       fredy.execute().then((listings) => {
         expect(listings).to.be.a('array');
 

test/provider/immonet.test.js

@@ -1,3 +1,4 @@
+const similarityCache = require('../../lib/services/similarity-check/similarityCache');
 const mockNotification = require('../mocks/mockNotification');
 const providerConfig = require('./testProvider.json');
 const mockStore = require('../mocks/mockStore');
@@ -6,6 +7,10 @@ const expect = require('chai').expect;
 const provider = require('../../lib/provider/immonet');
 
 describe('#immonet testsuite()', () => {
+  after(() => {
+    similarityCache.stopCacheCleanup();
+  });
+
   provider.init(providerConfig.immonet, [], []);
   const Fredy = proxyquire('../../lib/FredyRuntime', {
     './services/storage/listingsStorage': {
@@ -16,7 +21,7 @@ describe('#immonet testsuite()', () => {
 
   it('should test immonet provider', async () => {
     return await new Promise((resolve) => {
-      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1');
+      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1', similarityCache);
       fredy.execute().then((listing) => {
         expect(listing).to.be.a('array');
 

test/provider/immoscout.test.js

@@ -1,3 +1,4 @@
+const similarityCache = require('../../lib/services/similarity-check/similarityCache');
 const mockNotification = require('../mocks/mockNotification');
 const providerConfig = require('./testProvider.json');
 const mockStore = require('../mocks/mockStore');
@@ -7,6 +8,9 @@ const provider = require('../../lib/provider/immoscout');
 const scrapingAnt = require('../../lib/services/scrapingAnt');
 
 describe('#immoscout testsuite()', () => {
+  after(() => {
+    similarityCache.stopCacheCleanup();
+  });
   provider.init(providerConfig.immoscout, [], []);
   const Fredy = proxyquire('../../lib/FredyRuntime', {
     './services/storage/listingsStorage': {
@@ -25,7 +29,7 @@ describe('#immoscout testsuite()', () => {
         return;
       }
 
-      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1');
+      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1', similarityCache);
       fredy.execute().then((listing) => {
         expect(listing).to.be.a('array');
 

test/provider/immowelt.test.js

@@ -1,3 +1,4 @@
+const similarityCache = require('../../lib/services/similarity-check/similarityCache');
 const mockNotification = require('../mocks/mockNotification');
 const providerConfig = require('./testProvider.json');
 const mockStore = require('../mocks/mockStore');
@@ -6,6 +7,9 @@ const expect = require('chai').expect;
 const provider = require('../../lib/provider/immowelt');
 
 describe('#immowelt testsuite()', () => {
+  after(() => {
+    similarityCache.stopCacheCleanup();
+  });
   it('should test immowelt provider', async () => {
     provider.init(providerConfig.immowelt, [], []);
     const Fredy = proxyquire('../../lib/FredyRuntime', {
@@ -16,7 +20,7 @@ describe('#immowelt testsuite()', () => {
     });
 
     return await new Promise((resolve) => {
-      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1');
+      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1', similarityCache);
       fredy.execute().then((listing) => {
         expect(listing).to.be.a('array');
 

test/provider/kleinanzeigen.test.js

@@ -1,3 +1,4 @@
+const similarityCache = require('../../lib/services/similarity-check/similarityCache');
 const mockNotification = require('../mocks/mockNotification');
 const providerConfig = require('./testProvider.json');
 const mockStore = require('../mocks/mockStore');
@@ -6,6 +7,9 @@ const expect = require('chai').expect;
 const provider = require('../../lib/provider/kleinanzeigen');
 
 describe('#kleinanzeigen testsuite()', () => {
+  after(() => {
+    similarityCache.stopCacheCleanup();
+  });
   it('should test kleinanzeigen provider', async () => {
     provider.init(providerConfig.kleinanzeigen, [], []);
     const Fredy = proxyquire('../../lib/FredyRuntime', {
@@ -16,7 +20,7 @@ describe('#kleinanzeigen testsuite()', () => {
     });
 
     return await new Promise((resolve) => {
-      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1');
+      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1', similarityCache);
       fredy.execute().then((listing) => {
         expect(listing).to.be.a('array');
 

test/provider/neubauKompass.test.js

@@ -1,3 +1,4 @@
+const similarityCache = require('../../lib/services/similarity-check/similarityCache');
 const mockNotification = require('../mocks/mockNotification');
 const providerConfig = require('./testProvider.json');
 const mockStore = require('../mocks/mockStore');
@@ -6,6 +7,9 @@ const expect = require('chai').expect;
 const provider = require('../../lib/provider/neubauKompass');
 
 describe('#neubauKompass testsuite()', () => {
+  after(() => {
+    similarityCache.stopCacheCleanup();
+  });
   provider.init(providerConfig.neubauKompass, [], []);
   const Fredy = proxyquire('../../lib/FredyRuntime', {
     './services/storage/listingsStorage': {
@@ -16,7 +20,7 @@ describe('#neubauKompass testsuite()', () => {
 
   it('should test neubauKompass provider', async () => {
     return await new Promise((resolve) => {
-      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1');
+      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1', similarityCache);
       fredy.execute().then((listing) => {
         expect(listing).to.be.a('array');
 

test/provider/testProvider.json

@@ -21,7 +21,7 @@
     "enabled": true
   },
   "kleinanzeigen": {
-    "url": "https://www.ebay-kleinanzeigen.de/s-wohnung-kaufen/duesseldorf/anzeige:angebote/preis::420000/wohnung/k0c196l2068r5+wohnung_kaufen.qm_d:90,+wohnung_kaufen.zimmer_d:3.5,",
+    "url": "https://www.ebay-kleinanzeigen.de/s-immobilien/duesseldorf/anzeige:angebote/wohnung/k0c195l2068r5",
     "enabled": true
   },
   "neubauKompass": {

test/provider/wgGesucht.test.js

@@ -1,3 +1,4 @@
+const similarityCache = require('../../lib/services/similarity-check/similarityCache');
 const mockNotification = require('../mocks/mockNotification');
 const providerConfig = require('./testProvider.json');
 const mockStore = require('../mocks/mockStore');
@@ -6,6 +7,9 @@ const expect = require('chai').expect;
 const provider = require('../../lib/provider/wgGesucht');
 
 describe('#wgGesucht testsuite()', () => {
+  after(() => {
+    similarityCache.stopCacheCleanup();
+  });
   provider.init(providerConfig.wgGesucht, [], []);
   const Fredy = proxyquire('../../lib/FredyRuntime', {
     './services/storage/listingsStorage': {
@@ -16,7 +20,7 @@ describe('#wgGesucht testsuite()', () => {
 
   it('should test wgGesucht provider', async () => {
     return await new Promise((resolve) => {
-      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1');
+      const fredy = new Fredy(provider.config, null, provider.metaInformation.id, 'test1', similarityCache);
       fredy.execute().then((listing) => {
         expect(listing).to.be.a('array');
         const notificationObj = mockNotification.get();

test/similarity/similarity.test.js

@@ -0,0 +1,39 @@
+const SimilarityCacheEntry = require('../../lib/services/similarity-check/SimilarityCacheEntry');
+const expect = require('chai').expect;
+
+describe('similarityCheck', () => {
+  describe('#similarityCheck()', () => {
+    it('should be false', () => {
+      const check = new SimilarityCacheEntry(0);
+      check.setCacheEntry('Hallo');
+      expect(check.hasSimilarEntries('Welt')).to.be.false;
+    });
+    it('should be true', () => {
+      const check = new SimilarityCacheEntry(0);
+      check.setCacheEntry('Hallo');
+      expect(check.hasSimilarEntries('hallo')).to.be.true;
+    });
+    it('should be true', () => {
+      const check = new SimilarityCacheEntry(0);
+      check.setCacheEntry('Selling an incredible house in san francisco');
+      expect(check.hasSimilarEntries('incredible house in san francisco for sale')).to.be.true;
+    });
+    it('should be true', () => {
+      const check = new SimilarityCacheEntry(0);
+      check.setCacheEntry('a');
+      check.setCacheEntry('b');
+      check.setCacheEntry('c');
+      check.setCacheEntry('d');
+      expect(check.hasSimilarEntries('b')).to.be.true;
+    });
+    it('should be false', () => {
+      const check = new SimilarityCacheEntry(0);
+      check.setCacheEntry(
+        'The index is known by several other names, especially Sørensen–Dice index,[3] Sørensen index and Dice\'s coefficient. Other variations include the "similarity coefficient" or "index", such as Dice similarity coefficient (DSC). Common alternate spellings for Sørensen are Sorenson, Soerenson and Sörenson, and all three can also be seen with the –sen ending.'
+      );
+      check.setCacheEntry(
+        'where |X| and |Y| are the cardinalities of the two sets (i.e. the number of elements in each set). The Sørensen index equals twice the number of elements common to both sets divided by the sum of the number of elements in each set.'
+      );
+    });
+  });
+});

ui/src/views/login/Login.js

@@ -40,9 +40,8 @@ export default function Login() {
 
   return (
     <div className="login">
+      <div className="login__bgImage" style={{ background: `url("${cityBackground}")` }} />
       <Logo />
-      <div className="login__bgImage" style={{ background: `url(${cityBackground})` }} />
-
       <form>
         <div className="login__loginWrapper">
           {error && <Message negative icon="error" content={error} />}

ui/src/views/login/login.less

@@ -2,18 +2,17 @@
   display: flex;
   justify-content: center;
   align-items: center;
-  width:100%;
+  width: 100%;
   height: 100%;
 
   &__bgImage {
     background-size: cover;
     filter: blur(8px);
     -webkit-filter: blur(8px);
-    background-size: cover;
     position: absolute;
     top: 0;
     left: 0;
-    z-index: -1;
+    z-index: 0;
     right: 0;
     bottom: 0;
   }
@@ -23,9 +22,14 @@
     border-radius: 30px;
     height: 25rem;
     width: 30rem;
+    z-index: 1;
     background-color: #151313ab;
     display: flex;
     flex-direction: column;
     padding: 2rem;
   }
+
+  form {
+    z-index: 1;
+  }
 }