[#1833] Add frontend tests for filter glob (#1841)

There is currently no testing done for the new front-end change 
in filter glob related functionalities. This may result in regression
bugs in the future that can go undetected.

Let's add tests for these new frontend changes made for the filter glob
functionalities to ensure this feature works as expected and facilitate
future testing.

frontend/cypress/tests/codeView/codeView_filterGlob.js

@@ -0,0 +1,198 @@
+describe('filter glob', () => {
+  it('check filter glob radio button is clickable', () => {
+    // open the code panel
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    // click on filter glob radio button
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    // filter by file type should be unchecked
+    cy.get('.radio-button--checkbox')
+        .should('not.be.checked');
+  });
+
+  it('check no filter glob input should show all file types by default', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    // the contents of all the files should be visible
+    cy.get('#tab-authorship .files', { timeout: 90000 })
+        .should('be.visible');
+  });
+
+  it('check filter glob input should be in focus after click', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    // click on input box
+    cy.get('#search')
+        .click()
+        .should('have.focus');
+  });
+
+  it('check filter glob input should have default empty value', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    cy.get('#search')
+        .should('have.value', '');
+  });
+
+  it('check deleting previously searched input to filter empty input by enter should show all file types', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    // enter some input
+    cy.get('#search')
+        .type('an input');
+
+    // submit some input
+    cy.get('#search')
+        .type('{enter}');
+
+    // delete previous input
+    cy.get('#search')
+        .clear();
+
+    // enter on empty input
+    cy.get('#search')
+        .type('{enter}');
+
+    cy.get('#tab-authorship .files', { timeout: 90000 })
+        .should('be.visible');
+  });
+
+  it('check deleting previously searched input to filter empty input by clicking should show all file types', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    cy.get('#search')
+        .type('an input');
+
+    cy.get('#submit-button')
+        .click();
+
+    cy.get('#search')
+        .clear();
+
+    // click 'Filter' on empty input
+    cy.get('#submit-button')
+        .click();
+
+    cy.get('#tab-authorship .files', { timeout: 90000 })
+        .should('be.visible');
+  });
+
+  it('check request to filter invalid glob by enter should not show any files', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    cy.get('#tab-authorship .files', { timeout: 90000 })
+        .should('be.visible');
+
+    cy.get('#search')
+        .type('invalid glob');
+
+    cy.get('#search')
+        .type('{enter}');
+
+    // no file should be shown
+    cy.get('#tab-authorship .files')
+        .should('not.be.visible');
+  });
+
+  it('check request to filter invalid glob by clicking should not show any files', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    cy.get('#tab-authorship .files', { timeout: 90000 })
+        .should('be.visible');
+
+    cy.get('#search')
+        .type('invalid glob');
+
+    cy.get('#submit-button')
+        .click();
+
+    cy.get('#tab-authorship .files')
+        .should('not.be.visible');
+  });
+
+  it('check filter glob should only show files with that extension', () => {
+    cy.get('.icon-button.fa-code')
+        .should('be.visible')
+        .first()
+        .click();
+
+    cy.get('.radio-button--search')
+        .should('be.visible')
+        .click();
+
+    // try java
+    cy.get('#search')
+        .type('*java');
+
+    cy.get('#submit-button')
+        .click();
+
+    cy.get('#tab-authorship .files').then(($files) => {
+      // check if there is any file with .java extension
+      if ($files.hasClass('path')) {
+        // check each file for .java extension
+        cy.get('.title > .path > span')
+            .then(($spans) => {
+              $spans.toArray().forEach((span) => {
+                cy.wrap(span).contains('.java');
+              });
+            });
+      }
+    });
+  });
+});