diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index 8d8e988..adc101a 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -9,7 +9,7 @@
       "version": "0.1.0",
       "dependencies": {
         "@ericblade/quagga2": "^1.8.4",
-        "@tanstack/react-query": "^5.52.1",
+        "@tanstack/react-query": "^5.59.15",
         "@tanstack/react-table": "^8.20.5",
         "@testing-library/jest-dom": "^5.17.0",
         "@testing-library/react": "^13.4.0",
@@ -22,6 +22,7 @@
         "date-fns": "^3.6.0",
         "fast-xml-parser": "^4.5.0",
         "history": "^5.3.0",
+        "jest-canvas-mock": "^2.5.2",
         "react": "^18.3.1",
         "react-bootstrap": "^2.10.4",
         "react-dom": "^18.3.1",
@@ -3727,9 +3728,9 @@
       }
     },
     "node_modules/@tanstack/query-core": {
-      "version": "5.56.2",
-      "resolved": "https://registry.npmjs.org/@tanstack/query-core/-/query-core-5.56.2.tgz",
-      "integrity": "sha512-gor0RI3/R5rVV3gXfddh1MM+hgl0Z4G7tj6Xxpq6p2I03NGPaJ8dITY9Gz05zYYb/EJq9vPas/T4wn9EaDPd4Q==",
+      "version": "5.59.13",
+      "resolved": "https://registry.npmjs.org/@tanstack/query-core/-/query-core-5.59.13.tgz",
+      "integrity": "sha512-Oou0bBu/P8+oYjXsJQ11j+gcpLAMpqW42UlokQYEz4dE7+hOtVO9rVuolJKgEccqzvyFzqX4/zZWY+R/v1wVsQ==",
       "license": "MIT",
       "funding": {
         "type": "github",
@@ -3737,12 +3738,12 @@
       }
     },
     "node_modules/@tanstack/react-query": {
-      "version": "5.56.2",
-      "resolved": "https://registry.npmjs.org/@tanstack/react-query/-/react-query-5.56.2.tgz",
-      "integrity": "sha512-SR0GzHVo6yzhN72pnRhkEFRAHMsUo5ZPzAxfTMvUxFIDVS6W9LYUp6nXW3fcHVdg0ZJl8opSH85jqahvm6DSVg==",
+      "version": "5.59.15",
+      "resolved": "https://registry.npmjs.org/@tanstack/react-query/-/react-query-5.59.15.tgz",
+      "integrity": "sha512-QbVlAkTI78wB4Mqgf2RDmgC0AOiJqer2c5k9STOOSXGv1S6ZkY37r/6UpE8DbQ2Du0ohsdoXgFNEyv+4eDoPEw==",
       "license": "MIT",
       "dependencies": {
-        "@tanstack/query-core": "5.56.2"
+        "@tanstack/query-core": "5.59.13"
       },
       "funding": {
         "type": "github",
@@ -6655,6 +6656,12 @@
         "node": ">=4"
       }
     },
+    "node_modules/cssfontparser": {
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/cssfontparser/-/cssfontparser-1.2.1.tgz",
+      "integrity": "sha512-6tun4LoZnj7VN6YeegOVb67KBX/7JJsqvj+pv3ZA7F878/eN33AbGa5b/S/wXxS/tcp8nc40xRUrsPlxIyNUPg==",
+      "license": "MIT"
+    },
     "node_modules/cssnano": {
       "version": "5.1.15",
       "resolved": "https://registry.npmjs.org/cssnano/-/cssnano-5.1.15.tgz",
@@ -10610,6 +10617,16 @@
         }
       }
     },
+    "node_modules/jest-canvas-mock": {
+      "version": "2.5.2",
+      "resolved": "https://registry.npmjs.org/jest-canvas-mock/-/jest-canvas-mock-2.5.2.tgz",
+      "integrity": "sha512-vgnpPupjOL6+L5oJXzxTxFrlGEIbHdZqFU+LFNdtLxZ3lRDCl17FlTMM7IatoRQkrcyOTMlDinjUguqmQ6bR2A==",
+      "license": "MIT",
+      "dependencies": {
+        "cssfontparser": "^1.2.1",
+        "moo-color": "^1.0.2"
+      }
+    },
     "node_modules/jest-changed-files": {
       "version": "27.5.1",
       "resolved": "https://registry.npmjs.org/jest-changed-files/-/jest-changed-files-27.5.1.tgz",
@@ -12147,6 +12164,15 @@
         "mkdirp": "bin/cmd.js"
       }
     },
+    "node_modules/moo-color": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/moo-color/-/moo-color-1.0.3.tgz",
+      "integrity": "sha512-i/+ZKXMDf6aqYtBhuOcej71YSlbjT3wCO/4H1j8rPvxDJEifdwgg5MaFyu6iYAT8GBZJg2z0dkgK4YMzvURALQ==",
+      "license": "MIT",
+      "dependencies": {
+        "color-name": "^1.1.4"
+      }
+    },
     "node_modules/ms": {
       "version": "2.1.3",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
diff --git a/frontend/package.json b/frontend/package.json
index c1ddcba..c201ae0 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -5,7 +5,7 @@
   "proxy": "http://localhost:3001",
   "dependencies": {
     "@ericblade/quagga2": "^1.8.4",
-    "@tanstack/react-query": "^5.52.1",
+    "@tanstack/react-query": "^5.59.15",
     "@tanstack/react-table": "^8.20.5",
     "@testing-library/jest-dom": "^5.17.0",
     "@testing-library/react": "^13.4.0",
@@ -18,6 +18,7 @@
     "date-fns": "^3.6.0",
     "fast-xml-parser": "^4.5.0",
     "history": "^5.3.0",
+    "jest-canvas-mock": "^2.5.2",
     "react": "^18.3.1",
     "react-bootstrap": "^2.10.4",
     "react-dom": "^18.3.1",
@@ -31,7 +32,7 @@
   "scripts": {
     "start": "react-scripts start",
     "build": "react-scripts build",
-    "test": "react-scripts test",
+    "test": "react-scripts test --testPathPattern='(/__tests__/.*|(\\.|/)(test|spec))\\.[jt]sx?$'",
     "eject": "react-scripts eject"
   },
   "eslintConfig": {
diff --git a/frontend/src/App.test.tsx b/frontend/src/App.test.tsx
deleted file mode 100644
index 2a68616..0000000
--- a/frontend/src/App.test.tsx
+++ /dev/null
@@ -1,9 +0,0 @@
-import React from 'react';
-import { render, screen } from '@testing-library/react';
-import App from './App';
-
-test('renders learn react link', () => {
-  render(<App />);
-  const linkElement = screen.getByText(/learn react/i);
-  expect(linkElement).toBeInTheDocument();
-});
diff --git a/frontend/src/pages/Main/utils/__tests__/tryDeutscheNationalBibliothekApi.test.ts b/frontend/src/pages/Main/utils/__tests__/tryDeutscheNationalBibliothekApi.test.ts
new file mode 100644
index 0000000..808657e
--- /dev/null
+++ b/frontend/src/pages/Main/utils/__tests__/tryDeutscheNationalBibliothekApi.test.ts
@@ -0,0 +1,72 @@
+import { cleanup } from "@testing-library/react";
+import { tryDeutscheNationalBibliothekApi } from "../tryDeutscheNationalBibliothekApi";
+
+const dnbBookMock = {
+  text: () =>
+    `<?xml version="1.0" encoding="UTF-8"?>
+        <searchRetrieveResponse xmlns="http://www.loc.gov/zing/srw/"><version>1.1</version><numberOfRecords>1</numberOfRecords><records><record><recordSchema>RDFxml</recordSchema><recordPacking>xml</recordPacking><recordData><rdf:RDF xmlns:schema="http://schema.org/" xmlns:gndo="https://d-nb.info/standards/elementset/gnd#" xmlns:lib="http://purl.org/library/" xmlns:owl="http://www.w3.org/2002/07/owl#" xmlns:xsd="http://www.w3.org/2001/XMLSchema#" xmlns:skos="http://www.w3.org/2004/02/skos/core#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" xmlns:editeur="https://ns.editeur.org/thema/" xmlns:geo="http://www.opengis.net/ont/geosparql#" xmlns:umbel="http://umbel.org/umbel#" xmlns:naf="https://id.loc.gov/authorities/names/" xmlns:rdau="http://rdaregistry.info/Elements/u/" xmlns:sf="http://www.opengis.net/ont/sf#" xmlns:bflc="http://id.loc.gov/ontologies/bflc/" xmlns:thesoz="http://lod.gesis.org/thesoz/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:isbd="http://iflastandards.info/ns/isbd/elements/" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:mesh="http://id.nlm.nih.gov/mesh/vocab#" xmlns:ram="https://data.bnf.fr/ark:/12148/" xmlns:mo="http://purl.org/ontology/mo/" xmlns:marcRole="http://id.loc.gov/vocabulary/relators/" xmlns:agrelon="https://d-nb.info/standards/elementset/agrelon#" xmlns:dcmitype="http://purl.org/dc/dcmitype/" xmlns:nsogg="https://purl.org/bncf/tid/" xmlns:dnbt="https://d-nb.info/standards/elementset/dnb#" xmlns:dbp="http://dbpedia.org/property/" xmlns:embne="https://datos.bne.es/resource/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dnb_intern="http://dnb.de/" xmlns:madsrdf="http://www.loc.gov/mads/rdf/v1#" xmlns:cidoc="http://www.cidoc-crm.org/cidoc-crm/" xmlns:dcatde="http://dcat-ap.de/def/dcatde/" xmlns:v="http://www.w3.org/2006/vcard/ns#" xmlns:ebu="http://www.ebu.ch/metadata/ontologies/ebucore/ebucore#" xmlns:wdrs="http://www.w3.org/2007/05/powder-s#" xmlns:gbv="http://purl.org/ontology/gbv/" xmlns:bibo="http://purl.org/ontology/bibo/" xmlns:agrovoc="https://aims.fao.org/aos/agrovoc/" xmlns:lcsh="https://id.loc.gov/authorities/subjects/" xmlns:dc="http://purl.org/dc/elements/1.1/">
+        <rdf:Description rdf:about="https://d-nb.info/962361321">
+	    <rdf:type rdf:resource="http://purl.org/ontology/bibo/Document"/>
+	    <dcterms:medium rdf:resource="http://rdaregistry.info/termList/RDACarrierType/1044"/>
+	    <rdau:P60049 rdf:resource="http://rdaregistry.info/termList/RDAContentType/1020"/>
+	    <rdau:P60050 rdf:resource="http://rdaregistry.info/termList/RDAMediaType/1007"/>
+	    <rdau:P60048 rdf:resource="http://rdaregistry.info/termList/RDACarrierType/1049"/>
+	    <dc:identifier rdf:datatype="http://www.w3.org/2001/XMLSchema#string">(DE-101)962361321</dc:identifier>
+	    <bibo:isbn13 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">9783898641227</bibo:isbn13>
+	    <rdau:P60521 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Pp. : DM 79.00, EUR 41.00 (ab 1.1.2002), sfr 70.00, S 577.00</rdau:P60521>
+	    <bibo:isbn10 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">3898641228</bibo:isbn10>
+	    <rdau:P60521 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Pp. : DM 79.00, EUR 41.00 (ab 1.1.2002), sfr 70.00, S 577.00</rdau:P60521>
+	    <dc:identifier rdf:datatype="http://www.w3.org/2001/XMLSchema#string">(OCoLC)76300394</dc:identifier>
+	    <rdau:P60049 rdf:resource="https://d-nb.info/gnd/4123623-3"/>
+	    <rdau:P60327 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Gunter Saake ; Kai-Uwe Sattler</rdau:P60327>
+
+	    <dc:title rdf:datatype="http://www.w3.org/2001/XMLSchema#string">mockedbook</dc:title>
+
+	    <dcterms:creator rdf:resource="https://d-nb.info/gnd/122164458"/>
+	    <marcRole:aut rdf:resource="https://d-nb.info/gnd/122164458"/>
+	    <marcRole:aut rdf:resource="https://d-nb.info/gnd/120420392"/>
+	    <bibo:edition rdf:datatype="http://www.w3.org/2001/XMLSchema#string">1. Aufl.</bibo:edition>
+	    <dc:publisher rdf:datatype="http://www.w3.org/2001/XMLSchema#string">dpunkt-Verl.</dc:publisher>
+	    <rdau:P60163 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Heidelberg</rdau:P60163>
+	    <rdau:P60333 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">Heidelberg : dpunkt-Verl.</rdau:P60333>
+	    <rdau:P60539 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">25 cm</rdau:P60539>
+	    <rdau:P60470 xml:lang="de">Ill.</rdau:P60470>
+	    <rdau:P60470 xml:lang="de">Literaturverz. S. 483 - 486</rdau:P60470>
+	    <dcterms:subject rdf:resource="https://d-nb.info/gnd/4011146-5"/>
+	    <dcterms:subject rdf:resource="https://d-nb.info/gnd/4401313-9"/>
+	    <dcterms:subject rdf:resource="https://d-nb.info/gnd/4001183-5"/>
+	    <dcterms:subject rdf:resource="https://d-nb.info/gnd/4401313-9"/>
+	    <dcterms:tableOfContents rdf:resource="https://d-nb.info/962361321/04"/>
+	    <wdrs:describedby>
+		    <rdf:Description rdf:about="https://d-nb.info/962361321/about">
+		    	<dcterms:license rdf:resource="http://creativecommons.org/publicdomain/zero/1.0/"/>
+		    	<dcterms:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2024-10-13T04:31:46.000</dcterms:modified>
+		    </rdf:Description>
+	    </wdrs:describedby>
+
+	    <dcterms:issued rdf:datatype="http://www.w3.org/2001/XMLSchema#string">2024</dcterms:issued>
+
+	    <rdau:P60493 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">eine Einführung mit Java</rdau:P60493>
+	    <isbd:P1053 rdf:datatype="http://www.w3.org/2001/XMLSchema#string">XVI, 494 S.</isbd:P1053>
+	    <owl:sameAs rdf:resource="http://hub.culturegraph.org/resource/DNB-962361321"/>
+    </rdf:Description>
+    </rdf:RDF></recordData><recordPosition>1</recordPosition></record></records><echoedSearchRetrieveRequest><version>1.1</version><query>9783898641227</query><xQuery xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/></echoedSearchRetrieveRequest></searchRetrieveResponse>`,
+};
+
+describe("tryDeutscheNationalBibliothekApi", () => {
+  it("should parse dnb response to book", async () => {
+    global.fetch = jest.fn(() => Promise.resolve(dnbBookMock)) as jest.Mock;
+
+    const book = await tryDeutscheNationalBibliothekApi("mocked-isbn");
+
+    expect(book).toStrictEqual({
+      published: 2024,
+      title: "mockedbook",
+    });
+  });
+
+  afterAll(() => {
+    jest.clearAllMocks();
+    cleanup();
+  });
+});
diff --git a/frontend/src/pages/Main/utils/__tests__/tryGoogleBooksApi.test.ts b/frontend/src/pages/Main/utils/__tests__/tryGoogleBooksApi.test.ts
new file mode 100644
index 0000000..5e93a95
--- /dev/null
+++ b/frontend/src/pages/Main/utils/__tests__/tryGoogleBooksApi.test.ts
@@ -0,0 +1,33 @@
+import { cleanup } from "@testing-library/react";
+import { tryGoogleBooksApi } from "../tryGoogleBooksApi";
+
+const goolgeBooksMock = {
+  json: () => ({
+    items: [
+      {
+        volumeInfo: {
+          publishedDate: "2024-10-31",
+          title: "mockedbook",
+        },
+      },
+    ],
+  }),
+};
+
+describe("tryGoogleBooksApi", () => {
+  it("should parse google response to book", async () => {
+    global.fetch = jest.fn(() => Promise.resolve(goolgeBooksMock)) as jest.Mock;
+
+    const book = await tryGoogleBooksApi("mocked-isbn");
+
+    expect(book).toStrictEqual({
+      published: "2024",
+      title: "mockedbook",
+    });
+  });
+
+  afterAll(() => {
+    jest.clearAllMocks();
+    cleanup();
+  });
+});
diff --git a/frontend/src/shared/components/modals/__tests__/AuthenticationModal.test.tsx b/frontend/src/shared/components/modals/__tests__/AuthenticationModal.test.tsx
new file mode 100644
index 0000000..ad856f6
--- /dev/null
+++ b/frontend/src/shared/components/modals/__tests__/AuthenticationModal.test.tsx
@@ -0,0 +1,26 @@
+import { render } from "@testing-library/react";
+import { AuthenticationModal } from "../AuthenticationModal";
+
+describe("AuthenticationModal", () => {
+  it("renders as admin verification correctly", () => {
+    const view = render(
+      <AuthenticationModal
+        open={true}
+        onClose={() => undefined}
+        isUpdate={false}
+      />
+    );
+    expect(view.baseElement).toMatchSnapshot();
+  });
+
+  it("renders as admin pw change correctly", () => {
+    const view = render(
+      <AuthenticationModal
+        open={true}
+        onClose={() => undefined}
+        isUpdate={true}
+      />
+    );
+    expect(view.baseElement).toMatchSnapshot();
+  });
+});
diff --git a/frontend/src/shared/components/modals/__tests__/BookModal.test.tsx b/frontend/src/shared/components/modals/__tests__/BookModal.test.tsx
new file mode 100644
index 0000000..84b271d
--- /dev/null
+++ b/frontend/src/shared/components/modals/__tests__/BookModal.test.tsx
@@ -0,0 +1,30 @@
+import { render } from "@testing-library/react";
+import { BookModal } from "../BookModal";
+
+describe("BookModal", () => {
+  it("renders without a book", () => {
+    const view = render(<BookModal open={true} onClose={() => undefined} />);
+    expect(view.baseElement).toMatchSnapshot();
+  });
+
+  it("sets book as default value", () => {
+    const view = render(
+      <BookModal
+        open={true}
+        onClose={() => undefined}
+        book={{
+          id: 1,
+          uuid: "mockedbook",
+          isbn: "123",
+          title: "mockedbook",
+          published: 2024,
+          lastCheckoutDate: null,
+          checkoutBy: null,
+          shelf: "AVAILABLE",
+          contact: null,
+        }}
+      />
+    );
+    expect(view.baseElement).toMatchSnapshot();
+  });
+});
diff --git a/frontend/src/shared/components/modals/__tests__/__snapshots__/AuthenticationModal.test.tsx.snap b/frontend/src/shared/components/modals/__tests__/__snapshots__/AuthenticationModal.test.tsx.snap
new file mode 100644
index 0000000..cb78b1d
--- /dev/null
+++ b/frontend/src/shared/components/modals/__tests__/__snapshots__/AuthenticationModal.test.tsx.snap
@@ -0,0 +1,271 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`AuthenticationModal renders as admin pw change correctly 1`] = `
+<body
+  class="modal-open"
+  data-rr-ui-modal-open=""
+  style="padding-right: 2048px;"
+>
+  <div />
+  <div
+    class="fade modal-backdrop show"
+  />
+  <div
+    aria-modal="true"
+    class="fade modal show"
+    role="dialog"
+    style="display: block; padding-right: 0px;"
+    tabindex="-1"
+  >
+    <div
+      class="modal-dialog modal-dialog-centered"
+    >
+      <div
+        class="modal-content"
+      >
+        <div
+          class="modal-header"
+        >
+          <div
+            class="w-100 d-flex modal-title h4"
+          >
+            <svg
+              class="ml-0 mr-auto"
+              fill="currentColor"
+              height="50"
+              stroke="currentColor"
+              stroke-width="0"
+              version="1.1"
+              viewBox="0 0 17 17"
+              width="50"
+              xmlns="http://www.w3.org/2000/svg"
+            >
+              <g />
+              <path
+                d="M14.811 6.299l0.707-0.707-1.733-1.733 0.757-0.753-0.705-0.709-8.146 8.107c-0.484-0.336-1.070-0.535-1.703-0.535-1.654 0-3 1.346-3 3s1.346 3 3 3 3-1.346 3-3c0-0.661-0.222-1.268-0.585-1.764l5.264-5.238 1.738 1.738 0.707-0.707-1.737-1.736 0.701-0.698 1.735 1.735zM3.987 14.969c-1.103 0-2-0.897-2-2s0.897-2 2-2 2 0.897 2 2-0.897 2-2 2z"
+              />
+            </svg>
+            <h2
+              class="m-auto p-2"
+              style="text-align: center;"
+            >
+              Set new Admin key
+            </h2>
+            <button
+              class="ml-auto mr-0 btn btn-primary"
+              type="button"
+            >
+              <svg
+                fill="currentColor"
+                fill-rule="evenodd"
+                height="1em"
+                stroke="currentColor"
+                stroke-width="0"
+                viewBox="0 0 1024 1024"
+                width="1em"
+                xmlns="http://www.w3.org/2000/svg"
+              >
+                <path
+                  d="M799.855 166.312c.023.007.043.018.084.059l57.69 57.69c.041.041.052.06.059.084a.118.118 0 0 1 0 .069c-.007.023-.018.042-.059.083L569.926 512l287.703 287.703c.041.04.052.06.059.083a.118.118 0 0 1 0 .07c-.007.022-.018.042-.059.083l-57.69 57.69c-.041.041-.06.052-.084.059a.118.118 0 0 1-.069 0c-.023-.007-.042-.018-.083-.059L512 569.926 224.297 857.629c-.04.041-.06.052-.083.059a.118.118 0 0 1-.07 0c-.022-.007-.042-.018-.083-.059l-57.69-57.69c-.041-.041-.052-.06-.059-.084a.118.118 0 0 1 0-.069c.007-.023.018-.042.059-.083L454.073 512 166.371 224.297c-.041-.04-.052-.06-.059-.083a.118.118 0 0 1 0-.07c.007-.022.018-.042.059-.083l57.69-57.69c.041-.041.06-.052.084-.059a.118.118 0 0 1 .069 0c.023.007.042.018.083.059L512 454.073l287.703-287.702c.04-.041.06-.052.083-.059a.118.118 0 0 1 .07 0Z"
+                />
+              </svg>
+            </button>
+          </div>
+        </div>
+        <div
+          class="modal-body"
+        >
+          <form
+            class="mb-2"
+          >
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-4"
+              >
+                <label
+                  class="form-label"
+                >
+                  Current Password
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <input
+                  class="form-control"
+                  name="oldPassword"
+                  placeholder="Enter current admin password ..."
+                  type="password"
+                />
+                <div
+                  class="invalid-feedback"
+                >
+                  Old password is required
+                </div>
+              </div>
+            </div>
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-4"
+              >
+                <label
+                  class="form-label"
+                >
+                  New Password
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <input
+                  class="form-control"
+                  name="newPassword"
+                  placeholder="Enter new admin password ..."
+                  type="password"
+                />
+                <div
+                  class="invalid-feedback"
+                >
+                  New password is required
+                </div>
+              </div>
+            </div>
+             
+            <div
+              class="d-flex mx-auto mb-auto mt-2 w-100"
+            >
+              <button
+                class="btn btn-primary"
+                style="border-radius: 5px; margin-left: auto; margin-right: 10px;"
+                type="button"
+              >
+                Send
+              </button>
+            </div>
+          </form>
+        </div>
+      </div>
+    </div>
+  </div>
+</body>
+`;
+
+exports[`AuthenticationModal renders as admin verification correctly 1`] = `
+<body
+  class="modal-open"
+  data-rr-ui-modal-open=""
+  style="padding-right: 1024px;"
+>
+  <div />
+  <div
+    class="fade modal-backdrop show"
+  />
+  <div
+    aria-modal="true"
+    class="fade modal show"
+    role="dialog"
+    style="display: block; padding-right: 0px;"
+    tabindex="-1"
+  >
+    <div
+      class="modal-dialog modal-dialog-centered"
+    >
+      <div
+        class="modal-content"
+      >
+        <div
+          class="modal-header"
+        >
+          <div
+            class="w-100 d-flex modal-title h4"
+          >
+            <svg
+              class="ml-0 mr-auto"
+              fill="currentColor"
+              height="50"
+              stroke="currentColor"
+              stroke-width="0"
+              version="1.1"
+              viewBox="0 0 17 17"
+              width="50"
+              xmlns="http://www.w3.org/2000/svg"
+            >
+              <g />
+              <path
+                d="M14.811 6.299l0.707-0.707-1.733-1.733 0.757-0.753-0.705-0.709-8.146 8.107c-0.484-0.336-1.070-0.535-1.703-0.535-1.654 0-3 1.346-3 3s1.346 3 3 3 3-1.346 3-3c0-0.661-0.222-1.268-0.585-1.764l5.264-5.238 1.738 1.738 0.707-0.707-1.737-1.736 0.701-0.698 1.735 1.735zM3.987 14.969c-1.103 0-2-0.897-2-2s0.897-2 2-2 2 0.897 2 2-0.897 2-2 2z"
+              />
+            </svg>
+            <h2
+              class="m-auto p-2"
+              style="text-align: center;"
+            >
+              Admin Login
+            </h2>
+            <button
+              class="ml-auto mr-0 btn btn-primary"
+              type="button"
+            >
+              <svg
+                fill="currentColor"
+                fill-rule="evenodd"
+                height="1em"
+                stroke="currentColor"
+                stroke-width="0"
+                viewBox="0 0 1024 1024"
+                width="1em"
+                xmlns="http://www.w3.org/2000/svg"
+              >
+                <path
+                  d="M799.855 166.312c.023.007.043.018.084.059l57.69 57.69c.041.041.052.06.059.084a.118.118 0 0 1 0 .069c-.007.023-.018.042-.059.083L569.926 512l287.703 287.703c.041.04.052.06.059.083a.118.118 0 0 1 0 .07c-.007.022-.018.042-.059.083l-57.69 57.69c-.041.041-.06.052-.084.059a.118.118 0 0 1-.069 0c-.023-.007-.042-.018-.083-.059L512 569.926 224.297 857.629c-.04.041-.06.052-.083.059a.118.118 0 0 1-.07 0c-.022-.007-.042-.018-.083-.059l-57.69-57.69c-.041-.041-.052-.06-.059-.084a.118.118 0 0 1 0-.069c.007-.023.018-.042.059-.083L454.073 512 166.371 224.297c-.041-.04-.052-.06-.059-.083a.118.118 0 0 1 0-.07c.007-.022.018-.042.059-.083l57.69-57.69c.041-.041.06-.052.084-.059a.118.118 0 0 1 .069 0c.023.007.042.018.083.059L512 454.073l287.703-287.702c.04-.041.06-.052.083-.059a.118.118 0 0 1 .07 0Z"
+                />
+              </svg>
+            </button>
+          </div>
+        </div>
+        <div
+          class="modal-body"
+        >
+          <form
+            class="mb-2"
+          >
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col"
+              >
+                <input
+                  class="form-control"
+                  name="password"
+                  placeholder="Enter admin password ..."
+                  type="password"
+                />
+                <div
+                  class="invalid-feedback"
+                >
+                  Password is required
+                </div>
+              </div>
+            </div>
+            <div
+              class="d-flex mx-auto mb-auto mt-2 w-100"
+            >
+              <button
+                class="btn btn-primary"
+                style="border-radius: 5px; margin-left: auto; margin-right: 10px;"
+                type="button"
+              >
+                Send
+              </button>
+            </div>
+          </form>
+        </div>
+      </div>
+    </div>
+  </div>
+</body>
+`;
diff --git a/frontend/src/shared/components/modals/__tests__/__snapshots__/BookModal.test.tsx.snap b/frontend/src/shared/components/modals/__tests__/__snapshots__/BookModal.test.tsx.snap
new file mode 100644
index 0000000..8049ff5
--- /dev/null
+++ b/frontend/src/shared/components/modals/__tests__/__snapshots__/BookModal.test.tsx.snap
@@ -0,0 +1,495 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`BookModal renders without a book 1`] = `
+<body
+  class="modal-open"
+  data-rr-ui-modal-open=""
+  style="padding-right: 1024px;"
+>
+  <div />
+  <div
+    class="fade modal-backdrop show"
+  />
+  <div
+    aria-modal="true"
+    class="fade modal show"
+    role="dialog"
+    style="display: block; padding-right: 0px;"
+    tabindex="-1"
+  >
+    <div
+      class="modal-dialog modal-dialog-centered"
+    >
+      <div
+        class="modal-content"
+      >
+        <div
+          class="modal-header"
+        >
+          <div
+            class="w-100 d-flex modal-title h4"
+          >
+            <svg
+              class="ml-0 mr-auto"
+              fill="currentColor"
+              height="50"
+              stroke="currentColor"
+              stroke-width="0"
+              version="1.1"
+              viewBox="0 0 16 16"
+              width="50"
+              xmlns="http://www.w3.org/2000/svg"
+            >
+              <path
+                d="M14 2v13h-10.5c-0.829 0-1.5-0.672-1.5-1.5s0.671-1.5 1.5-1.5h9.5v-12h-10c-1.1 0-2 0.9-2 2v12c0 1.1 0.9 2 2 2h12v-14h-1z"
+              />
+              <path
+                d="M3.501 13v0c-0 0-0.001 0-0.001 0-0.276 0-0.5 0.224-0.5 0.5s0.224 0.5 0.5 0.5c0 0 0.001-0 0.001-0v0h9.498v-1h-9.498z"
+              />
+            </svg>
+            <h2
+              class="m-auto p-2"
+              style="text-align: center;"
+            >
+              Add new Book
+            </h2>
+            <button
+              class="ml-auto mr-0 btn btn-primary"
+              type="button"
+            >
+              <svg
+                fill="currentColor"
+                fill-rule="evenodd"
+                height="1em"
+                stroke="currentColor"
+                stroke-width="0"
+                viewBox="0 0 1024 1024"
+                width="1em"
+                xmlns="http://www.w3.org/2000/svg"
+              >
+                <path
+                  d="M799.855 166.312c.023.007.043.018.084.059l57.69 57.69c.041.041.052.06.059.084a.118.118 0 0 1 0 .069c-.007.023-.018.042-.059.083L569.926 512l287.703 287.703c.041.04.052.06.059.083a.118.118 0 0 1 0 .07c-.007.022-.018.042-.059.083l-57.69 57.69c-.041.041-.06.052-.084.059a.118.118 0 0 1-.069 0c-.023-.007-.042-.018-.083-.059L512 569.926 224.297 857.629c-.04.041-.06.052-.083.059a.118.118 0 0 1-.07 0c-.022-.007-.042-.018-.083-.059l-57.69-57.69c-.041-.041-.052-.06-.059-.084a.118.118 0 0 1 0-.069c.007-.023.018-.042.059-.083L454.073 512 166.371 224.297c-.041-.04-.052-.06-.059-.083a.118.118 0 0 1 0-.07c.007-.022.018-.042.059-.083l57.69-57.69c.041-.041.06-.052.084-.059a.118.118 0 0 1 .069 0c.023.007.042.018.083.059L512 454.073l287.703-287.702c.04-.041.06-.052.083-.059a.118.118 0 0 1 .07 0Z"
+                />
+              </svg>
+            </button>
+          </div>
+        </div>
+        <div
+          class="modal-body"
+        >
+          <form
+            class="mb-2"
+          >
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  ISBN
+                </label>
+              </div>
+              <div
+                class="d-flex flex-column col"
+              >
+                <div
+                  class="d-flex"
+                >
+                  <input
+                    class="form-control"
+                    name="isbn"
+                    style="border-radius: 5px 0px 0px 5px;"
+                  />
+                  <button
+                    class="mr-2 pt-0 btn btn-primary"
+                    style="border-radius: 0px 5px 5px 0px;"
+                    type="button"
+                  >
+                    <svg
+                      fill="currentColor"
+                      height="20"
+                      stroke="currentColor"
+                      stroke-width="0"
+                      version="1.1"
+                      viewBox="0 0 16 16"
+                      width="20"
+                      xmlns="http://www.w3.org/2000/svg"
+                    >
+                      <path
+                        d="M4.75 9.5c0 1.795 1.455 3.25 3.25 3.25s3.25-1.455 3.25-3.25-1.455-3.25-3.25-3.25-3.25 1.455-3.25 3.25zM15 4h-3.5c-0.25-1-0.5-2-1.5-2h-4c-1 0-1.25 1-1.5 2h-3.5c-0.55 0-1 0.45-1 1v9c0 0.55 0.45 1 1 1h14c0.55 0 1-0.45 1-1v-9c0-0.55-0.45-1-1-1zM8 13.938c-2.451 0-4.438-1.987-4.438-4.438s1.987-4.438 4.438-4.438c2.451 0 4.438 1.987 4.438 4.438s-1.987 4.438-4.438 4.438zM15 7h-2v-1h2v1z"
+                      />
+                    </svg>
+                  </button>
+                </div>
+                <div
+                  class="invalid-feedback"
+                  style="display: none;"
+                >
+                  ISBN is required
+                </div>
+              </div>
+            </div>
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  Title
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <input
+                  class="form-control"
+                  name="title"
+                />
+                <div
+                  class="invalid-feedback"
+                >
+                  Title is required
+                </div>
+              </div>
+            </div>
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  Year published
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <input
+                  class="form-control"
+                  name="published"
+                />
+                <div
+                  class="invalid-feedback"
+                >
+                  Year published is required
+                </div>
+              </div>
+            </div>
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  Shelf
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <select
+                  class="form-select"
+                  name="shelf"
+                >
+                  <option
+                    value="AVAILABLE"
+                  >
+                    available
+                  </option>
+                  <option
+                    value="FNORD1"
+                  >
+                    fnord1
+                  </option>
+                  <option
+                    value="FNORD2"
+                  >
+                    fnord2
+                  </option>
+                  <option
+                    value="SHARING"
+                  >
+                    sharing
+                  </option>
+                </select>
+                <div
+                  class="invalid-feedback"
+                >
+                  Shelf is required
+                </div>
+              </div>
+            </div>
+            <div
+              class="d-flex mx-auto mb-auto mt-2 w-100"
+            >
+              <button
+                class="btn btn-primary"
+                style="border-radius: 5px; margin-left: auto; margin-right: 10px;"
+                type="button"
+              >
+                Add Book
+              </button>
+            </div>
+          </form>
+        </div>
+      </div>
+    </div>
+  </div>
+</body>
+`;
+
+exports[`BookModal sets book as default value 1`] = `
+<body
+  class="modal-open"
+  data-rr-ui-modal-open=""
+  style="padding-right: 2048px;"
+>
+  <div />
+  <div
+    class="fade modal-backdrop show"
+  />
+  <div
+    aria-modal="true"
+    class="fade modal show"
+    role="dialog"
+    style="display: block; padding-right: 0px;"
+    tabindex="-1"
+  >
+    <div
+      class="modal-dialog modal-dialog-centered"
+    >
+      <div
+        class="modal-content"
+      >
+        <div
+          class="modal-header"
+        >
+          <div
+            class="w-100 d-flex modal-title h4"
+          >
+            <svg
+              class="ml-0 mr-auto"
+              fill="currentColor"
+              height="50"
+              stroke="currentColor"
+              stroke-width="0"
+              version="1.1"
+              viewBox="0 0 16 16"
+              width="50"
+              xmlns="http://www.w3.org/2000/svg"
+            >
+              <path
+                d="M14 2v13h-10.5c-0.829 0-1.5-0.672-1.5-1.5s0.671-1.5 1.5-1.5h9.5v-12h-10c-1.1 0-2 0.9-2 2v12c0 1.1 0.9 2 2 2h12v-14h-1z"
+              />
+              <path
+                d="M3.501 13v0c-0 0-0.001 0-0.001 0-0.276 0-0.5 0.224-0.5 0.5s0.224 0.5 0.5 0.5c0 0 0.001-0 0.001-0v0h9.498v-1h-9.498z"
+              />
+            </svg>
+            <h2
+              class="m-auto p-2"
+              style="text-align: center;"
+            >
+              Edit Book
+            </h2>
+            <button
+              class="ml-auto mr-0 btn btn-primary"
+              type="button"
+            >
+              <svg
+                fill="currentColor"
+                fill-rule="evenodd"
+                height="1em"
+                stroke="currentColor"
+                stroke-width="0"
+                viewBox="0 0 1024 1024"
+                width="1em"
+                xmlns="http://www.w3.org/2000/svg"
+              >
+                <path
+                  d="M799.855 166.312c.023.007.043.018.084.059l57.69 57.69c.041.041.052.06.059.084a.118.118 0 0 1 0 .069c-.007.023-.018.042-.059.083L569.926 512l287.703 287.703c.041.04.052.06.059.083a.118.118 0 0 1 0 .07c-.007.022-.018.042-.059.083l-57.69 57.69c-.041.041-.06.052-.084.059a.118.118 0 0 1-.069 0c-.023-.007-.042-.018-.083-.059L512 569.926 224.297 857.629c-.04.041-.06.052-.083.059a.118.118 0 0 1-.07 0c-.022-.007-.042-.018-.083-.059l-57.69-57.69c-.041-.041-.052-.06-.059-.084a.118.118 0 0 1 0-.069c.007-.023.018-.042.059-.083L454.073 512 166.371 224.297c-.041-.04-.052-.06-.059-.083a.118.118 0 0 1 0-.07c.007-.022.018-.042.059-.083l57.69-57.69c.041-.041.06-.052.084-.059a.118.118 0 0 1 .069 0c.023.007.042.018.083.059L512 454.073l287.703-287.702c.04-.041.06-.052.083-.059a.118.118 0 0 1 .07 0Z"
+                />
+              </svg>
+            </button>
+          </div>
+        </div>
+        <div
+          class="modal-body"
+        >
+          <form
+            class="mb-2"
+          >
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  ISBN
+                </label>
+              </div>
+              <div
+                class="d-flex flex-column col"
+              >
+                <div
+                  class="d-flex"
+                >
+                  <input
+                    class="form-control"
+                    name="isbn"
+                    style="border-radius: 5px 0px 0px 5px;"
+                  />
+                  <button
+                    class="mr-2 pt-0 btn btn-primary"
+                    style="border-radius: 0px 5px 5px 0px;"
+                    type="button"
+                  >
+                    <svg
+                      fill="currentColor"
+                      height="20"
+                      stroke="currentColor"
+                      stroke-width="0"
+                      version="1.1"
+                      viewBox="0 0 16 16"
+                      width="20"
+                      xmlns="http://www.w3.org/2000/svg"
+                    >
+                      <path
+                        d="M4.75 9.5c0 1.795 1.455 3.25 3.25 3.25s3.25-1.455 3.25-3.25-1.455-3.25-3.25-3.25-3.25 1.455-3.25 3.25zM15 4h-3.5c-0.25-1-0.5-2-1.5-2h-4c-1 0-1.25 1-1.5 2h-3.5c-0.55 0-1 0.45-1 1v9c0 0.55 0.45 1 1 1h14c0.55 0 1-0.45 1-1v-9c0-0.55-0.45-1-1-1zM8 13.938c-2.451 0-4.438-1.987-4.438-4.438s1.987-4.438 4.438-4.438c2.451 0 4.438 1.987 4.438 4.438s-1.987 4.438-4.438 4.438zM15 7h-2v-1h2v1z"
+                      />
+                    </svg>
+                  </button>
+                </div>
+                <div
+                  class="invalid-feedback"
+                  style="display: none;"
+                >
+                  ISBN is required
+                </div>
+              </div>
+            </div>
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  Title
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <input
+                  class="form-control"
+                  name="title"
+                />
+                <div
+                  class="invalid-feedback"
+                />
+              </div>
+            </div>
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  Year published
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <input
+                  class="form-control"
+                  name="published"
+                />
+                <div
+                  class="invalid-feedback"
+                />
+              </div>
+            </div>
+            <div
+              class="mb-2 row"
+            >
+              <div
+                class="col-sm-2"
+              >
+                <label
+                  class="form-label"
+                >
+                  Shelf
+                </label>
+              </div>
+              <div
+                class="col"
+              >
+                <select
+                  class="form-select"
+                  name="shelf"
+                >
+                  <option
+                    value="AVAILABLE"
+                  >
+                    available
+                  </option>
+                  <option
+                    value="FNORD1"
+                  >
+                    fnord1
+                  </option>
+                  <option
+                    value="FNORD2"
+                  >
+                    fnord2
+                  </option>
+                  <option
+                    value="SHARING"
+                  >
+                    sharing
+                  </option>
+                </select>
+                <div
+                  class="invalid-feedback"
+                />
+              </div>
+            </div>
+            <div
+              class="d-flex mx-auto mb-auto mt-2 w-100"
+            >
+              <button
+                class="btn btn-primary"
+                style="border-radius: 5px; margin-left: auto; margin-right: 10px;"
+                type="button"
+              >
+                Submit
+              </button>
+            </div>
+          </form>
+        </div>
+      </div>
+    </div>
+  </div>
+</body>
+`;
diff --git a/frontend/src/shared/utils/__tests__/getMedianOfCodeErrors.test.ts b/frontend/src/shared/utils/__tests__/getMedianOfCodeErrors.test.ts
new file mode 100644
index 0000000..8411e00
--- /dev/null
+++ b/frontend/src/shared/utils/__tests__/getMedianOfCodeErrors.test.ts
@@ -0,0 +1,69 @@
+import { QuaggaJSResultObject } from "@ericblade/quagga2";
+import { getMedianOfCodeErrors } from "../getMedianOfCodeErrors";
+
+export const createMockQuaggaResult = (
+  decodedCodes: Array<{
+    error?: number;
+    code: number;
+    start: number;
+    end: number;
+  }> = []
+): QuaggaJSResultObject => ({
+  codeResult: {
+    code: "123456",
+    start: 0,
+    end: 10,
+    codeset: 1,
+    startInfo: {
+      error: 0,
+      code: 1,
+      start: 0,
+      end: 5,
+    },
+    decodedCodes,
+    endInfo: {
+      error: 0,
+      code: 1,
+      start: 5,
+      end: 10,
+    },
+    direction: 1,
+    format: "QR",
+  },
+  barcodes: [],
+  line: [{ x: 0, y: 0 }],
+  angle: 0,
+  pattern: [],
+  box: [],
+  boxes: [],
+});
+
+describe("getMedianOfCodeErrors", () => {
+  it("should return the median of code errors when there are valid errors", () => {
+    const result = createMockQuaggaResult([
+      { error: 1, code: 1, start: 0, end: 5 },
+      { error: 3, code: 1, start: 5, end: 10 },
+      { error: 2, code: 1, start: 0, end: 10 },
+    ]);
+
+    const median = getMedianOfCodeErrors(result);
+    expect(median).toBe(2); // The median of [1, 3, 2] is 2
+  });
+
+  it("should return undefined when there are no code errors", () => {
+    const result = createMockQuaggaResult([
+      { code: 1, start: 0, end: 5 }, // No error property
+      { code: 1, start: 5, end: 10 },
+    ]);
+
+    const median = getMedianOfCodeErrors(result);
+    expect(median).toBeUndefined();
+  });
+
+  it("should handle an empty decodedCodes array", () => {
+    const result = createMockQuaggaResult([]);
+
+    const median = getMedianOfCodeErrors(result);
+    expect(median).toBeUndefined();
+  });
+});
diff --git a/frontend/src/shared/utils/__tests__/useAuthentication.test.tsx b/frontend/src/shared/utils/__tests__/useAuthentication.test.tsx
new file mode 100644
index 0000000..0f85e3e
--- /dev/null
+++ b/frontend/src/shared/utils/__tests__/useAuthentication.test.tsx
@@ -0,0 +1,66 @@
+import React from "react";
+import { render, waitFor, cleanup } from "@testing-library/react";
+import { AuthContext } from "../../../App";
+import { useAuth } from "../useAuthentication";
+
+const MockedComponent: React.FC = () => {
+  const { authenticated } = useAuth();
+  return <div>{authenticated}</div>;
+};
+
+let authenticated = false;
+const setAuthenticated = (args: boolean) => (authenticated = args);
+
+describe("useAuth", () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+    cleanup();
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    cleanup();
+  });
+
+  it("should set authenticated to true when fetch returns ok", async () => {
+    global.fetch = jest.fn(() => Promise.resolve({ ok: true })) as jest.Mock;
+
+    render(
+      <AuthContext.Provider value={{ authenticated, setAuthenticated }}>
+        <MockedComponent />
+      </AuthContext.Provider>
+    );
+
+    await waitFor(() => expect(fetch).toHaveBeenCalledTimes(1));
+
+    expect(authenticated).toBe(true);
+  });
+
+  it("should set authenticated to false when fetch returns not ok", async () => {
+    global.fetch = jest.fn(() => Promise.resolve({ ok: false })) as jest.Mock;
+
+    render(
+      <AuthContext.Provider value={{ authenticated, setAuthenticated }}>
+        <MockedComponent />
+      </AuthContext.Provider>
+    );
+
+    await waitFor(() => expect(fetch).toHaveBeenCalledTimes(1));
+
+    expect(authenticated).toBe(false);
+  });
+
+  it("should call fetch once", async () => {
+    global.fetch = jest.fn(() => Promise.resolve({ ok: false })) as jest.Mock;
+
+    render(
+      <AuthContext.Provider value={{ authenticated, setAuthenticated }}>
+        <MockedComponent />
+      </AuthContext.Provider>
+    );
+
+    await waitFor(() => {
+      expect(fetch).toHaveBeenCalledTimes(1);
+    });
+  });
+});
diff --git a/frontend/src/shared/utils/drawQuaggaProcessing.ts b/frontend/src/shared/utils/drawQuaggaProcessing.ts
new file mode 100644
index 0000000..6185a7b
--- /dev/null
+++ b/frontend/src/shared/utils/drawQuaggaProcessing.ts
@@ -0,0 +1,34 @@
+import Quagga, { QuaggaJSResultObject } from "@ericblade/quagga2";
+
+export const drawQuaggaProcessing = (result: QuaggaJSResultObject) => {
+  const drawingCtx = Quagga.canvas.ctx.overlay;
+  const drawingCanvas = Quagga.canvas.dom.overlay;
+  drawingCtx.font = "24px Arial";
+  drawingCtx.fillStyle = "green";
+  const width = drawingCanvas.getAttribute("width");
+  const height = drawingCanvas.getAttribute("height");
+
+  if (result) {
+    if (result.boxes && width && height) {
+      drawingCtx.clearRect(0, 0, parseInt(width), parseInt(height));
+      result.boxes
+        .filter((box) => box !== result.box)
+        .forEach((box) => {
+          Quagga.ImageDebug.drawPath(box, { x: 0, y: 1 }, drawingCtx, {
+            color: "purple",
+            lineWidth: 2,
+          });
+        });
+    }
+    if (result.box) {
+      Quagga.ImageDebug.drawPath(result.box, { x: 0, y: 1 }, drawingCtx, {
+        color: "blue",
+        lineWidth: 2,
+      });
+    }
+    if (result.codeResult && result.codeResult.code) {
+      drawingCtx.font = "24px Arial";
+      drawingCtx.fillText(result.codeResult.code, 10, 20);
+    }
+  }
+};
diff --git a/frontend/src/shared/utils/getMedianOfCodeErrors.ts b/frontend/src/shared/utils/getMedianOfCodeErrors.ts
new file mode 100644
index 0000000..e43e0ca
--- /dev/null
+++ b/frontend/src/shared/utils/getMedianOfCodeErrors.ts
@@ -0,0 +1,20 @@
+import { QuaggaJSResultObject } from "@ericblade/quagga2";
+
+export const getMedianOfCodeErrors = (result: QuaggaJSResultObject) => {
+  const errors = result.codeResult.decodedCodes.flatMap((x) => x.error);
+  const medianOfErrors = getMedian(errors);
+  return medianOfErrors;
+};
+
+export const getMedian = (arr: (number | undefined)[]) => {
+  const newArr = [...arr].filter((x) => typeof x !== "undefined");
+  if (!newArr.length) {
+    return;
+  }
+  newArr.sort((a, b) => a! - b!);
+  const half = Math.floor(newArr.length / 2);
+  if (newArr.length % 2 === 1) {
+    return newArr[half];
+  }
+  return (newArr[half - 1]! + newArr[half]!) / 2;
+};
diff --git a/frontend/src/shared/utils/useAuthentication.ts b/frontend/src/shared/utils/useAuthentication.ts
index b3d5c36..3d6e203 100644
--- a/frontend/src/shared/utils/useAuthentication.ts
+++ b/frontend/src/shared/utils/useAuthentication.ts
@@ -1,11 +1,10 @@
-import { useCallback, useContext } from "react";
+import { useCallback, useContext, useEffect } from "react";
 import { AuthContext } from "../../App";
-import { useQuery } from "@tanstack/react-query";
 
 type UseAuthHook = { authenticated: boolean };
 
 export const useAuth = (): UseAuthHook => {
-  const auth = useContext(AuthContext);
+  const { authenticated, setAuthenticated } = useContext(AuthContext);
 
   const authenticationCheck = useCallback(
     async () =>
@@ -16,17 +15,14 @@ export const useAuth = (): UseAuthHook => {
           "Content-Type": "application/json",
         },
       }).then((res) => {
-        auth.setAuthenticated?.(res.ok);
-        //react-query can't handle undefined without throwing a warning ...
-        return null;
+        setAuthenticated?.(res.ok);
       }),
-    [auth]
+    [setAuthenticated]
   );
 
-  useQuery({
-    queryFn: authenticationCheck,
-    queryKey: ["auth"],
-  });
+  useEffect(() => {
+    authenticationCheck();
+  }, [authenticationCheck]);
 
-  return auth;
+  return { authenticated };
 };
diff --git a/frontend/src/shared/utils/useScanner.ts b/frontend/src/shared/utils/useScanner.ts
index 70666b2..44aa7ee 100644
--- a/frontend/src/shared/utils/useScanner.ts
+++ b/frontend/src/shared/utils/useScanner.ts
@@ -3,6 +3,8 @@ import Quagga, {
   QuaggaJSResultObject,
 } from "@ericblade/quagga2";
 import { useState, useCallback, useEffect } from "react";
+import { getMedianOfCodeErrors } from "./getMedianOfCodeErrors";
+import { drawQuaggaProcessing } from "./drawQuaggaProcessing";
 
 const constraints = {
   width: 640,
@@ -29,28 +31,6 @@ export const useScanner = ({
 
   const [scannerRef, setScannerRef] = useState<HTMLDivElement | null>(null);
 
-  const getMedian = useCallback((arr: (number | undefined)[]) => {
-    const newArr = [...arr].filter((x) => typeof x !== "undefined");
-    if (!newArr.length) {
-      return;
-    }
-    newArr.sort((a, b) => a! - b!);
-    const half = Math.floor(newArr.length / 2);
-    if (newArr.length % 2 === 1) {
-      return newArr[half];
-    }
-    return (newArr[half - 1]! + newArr[half]!) / 2;
-  }, []);
-
-  const getMedianOfCodeErrors = useCallback(
-    (result: QuaggaJSResultObject) => {
-      const errors = result.codeResult.decodedCodes.flatMap((x) => x.error);
-      const medianOfErrors = getMedian(errors);
-      return medianOfErrors;
-    },
-    [getMedian]
-  );
-
   const errorCheck = useCallback(
     (result: QuaggaJSResultObject) => {
       if (!onDetected) {
@@ -66,42 +46,9 @@ export const useScanner = ({
         onDetected(result.codeResult.code);
       }
     },
-    [getMedianOfCodeErrors, onDetected]
+    [onDetected]
   );
 
-  const handleProcessed = (result: QuaggaJSResultObject) => {
-    const drawingCtx = Quagga.canvas.ctx.overlay;
-    const drawingCanvas = Quagga.canvas.dom.overlay;
-    drawingCtx.font = "24px Arial";
-    drawingCtx.fillStyle = "green";
-    const width = drawingCanvas.getAttribute("width");
-    const height = drawingCanvas.getAttribute("height");
-
-    if (result) {
-      if (result.boxes && width && height) {
-        drawingCtx.clearRect(0, 0, parseInt(width), parseInt(height));
-        result.boxes
-          .filter((box) => box !== result.box)
-          .forEach((box) => {
-            Quagga.ImageDebug.drawPath(box, { x: 0, y: 1 }, drawingCtx, {
-              color: "purple",
-              lineWidth: 2,
-            });
-          });
-      }
-      if (result.box) {
-        Quagga.ImageDebug.drawPath(result.box, { x: 0, y: 1 }, drawingCtx, {
-          color: "blue",
-          lineWidth: 2,
-        });
-      }
-      if (result.codeResult && result.codeResult.code) {
-        drawingCtx.font = "24px Arial";
-        drawingCtx.fillText(result.codeResult.code, 10, 20);
-      }
-    }
-  };
-
   const getCameraId = useCallback(async () => {
     const stream = await navigator.mediaDevices.getUserMedia({
       video: { facingMode: "environment" },
@@ -150,7 +97,7 @@ export const useScanner = ({
           locate: true,
         },
         async (err) => {
-          Quagga.onProcessed(handleProcessed);
+          Quagga.onProcessed(drawQuaggaProcessing);
 
           if (err) {
             return console.error("Error starting Quagga:", err);
@@ -170,7 +117,7 @@ export const useScanner = ({
     await Quagga.CameraAccess.release();
     await Quagga.stop();
     Quagga.offDetected(errorCheck);
-    Quagga.offProcessed(handleProcessed);
+    Quagga.offProcessed(drawQuaggaProcessing);
   }, [errorCheck]);
 
   useEffect(() => {