diff --git a/x-pack/plugins/code/public/components/main/side_tabs.tsx b/x-pack/plugins/code/public/components/main/side_tabs.tsx
index dcc4e5e11d0b6..16e1a17d22a10 100644
--- a/x-pack/plugins/code/public/components/main/side_tabs.tsx
+++ b/x-pack/plugins/code/public/components/main/side_tabs.tsx
@@ -71,7 +71,7 @@ class CodeSideTabs extends React.PureComponent<Props> {
         id: Tabs.file,
         name: 'File',
         content: fileTabContent,
-        'data-test-subj': 'codeFileTreeTab',
+        'data-test-subj': `codeFileTreeTab${this.sideTab === Tabs.file ? 'Active' : ''}`,
       },
       {
         id: Tabs.structure,
diff --git a/x-pack/test/functional/apps/code/explore_repository.ts b/x-pack/test/functional/apps/code/explore_repository.ts
index 3fb2ffa9dc22f..1a387e1769b71 100644
--- a/x-pack/test/functional/apps/code/explore_repository.ts
+++ b/x-pack/test/functional/apps/code/explore_repository.ts
@@ -229,71 +229,71 @@ export default function exploreRepositoryFunctonalTests({
       });
 
       // TODO(qianliang): blocked by https://github.com/elastic/code/issues/1163
-      // it('Click file/directory on the right panel', async () => {
-      //   log.debug('Click file/directory on the right panel');
-
-      //   // Wait the file tree to be rendered and click the 'src' folder on the file tree.
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeFileExplorerNode-src')).to.be(true);
-      //   });
-
-      //   await testSubjects.click('codeFileExplorerNode-src');
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeFileExplorerNode-models')).to.be(true);
-      //   });
-
-      //   await testSubjects.click('codeFileExplorerNode-models');
-      //   // Then the 'models' folder on the file tree.
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeFileExplorerNode-User.ts')).to.be(true);
-      //   });
-
-      //   await testSubjects.click('codeFileExplorerNode-User.ts');
-      //   // Then the 'User.ts' file on the file tree.
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeSourceViewer')).to.be(true);
-      //   });
-      // });
+      it('Click file/directory on the right panel', async () => {
+        log.debug('Click file/directory on the right panel');
+
+        // Wait the file tree to be rendered and click the 'src' folder on the file tree.
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeFileExplorerNode-src')).to.be(true);
+        });
+
+        await testSubjects.click('codeFileExplorerNode-src');
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeFileExplorerNode-models')).to.be(true);
+        });
+
+        await testSubjects.click('codeFileExplorerNode-models');
+        // Then the 'models' folder on the file tree.
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeFileExplorerNode-User.ts')).to.be(true);
+        });
+
+        await testSubjects.click('codeFileExplorerNode-User.ts');
+        // Then the 'User.ts' file on the file tree.
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeSourceViewer')).to.be(true);
+        });
+      });
 
       // TODO(qianliang): blocked by https://github.com/elastic/code/issues/1163
-      // it('Navigate source file via structure tree', async () => {
-      //   log.debug('Navigate source file via structure tree');
-      //   // Wait the file tree to be rendered and click the 'src' folder on the file tree.
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeFileExplorerNode-src')).to.be(true);
-      //   });
-
-      //   await testSubjects.click('codeFileExplorerNode-src');
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeFileExplorerNode-models')).to.be(true);
-      //   });
-
-      //   await testSubjects.click('codeFileExplorerNode-models');
-      //   // Then the 'models' folder on the file tree.
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeFileExplorerNode-User.ts')).to.be(true);
-      //   });
-
-      //   await testSubjects.click('codeFileExplorerNode-User.ts');
-      //   // Then the 'User.ts' file on the file tree.
-      //   await retry.try(async () => {
-      //     expect(await testSubjects.exists('codeSourceViewer')).to.be(true);
-      //     expect(await testSubjects.exists('codeStructureTreeTab')).to.be(true);
-      //   });
-
-      //   // Click the structure tree tab
-      //   await testSubjects.click('codeStructureTreeTab');
-      //   await retry.tryForTime(300000, async () => {
-      //     expect(await testSubjects.exists('codeStructureTreeNode-User')).to.be(true);
-
-      //     await testSubjects.click('codeStructureTreeNode-User');
-      //     await retry.tryForTime(120000, async () => {
-      //       const currentUrl: string = await browser.getCurrentUrl();
-      //       log.info(`Jump to url: ${currentUrl}`);
-      //       expect(currentUrl.indexOf('src/models/User.ts!L92:6') > 0).to.be(true);
-      //     });
-      //   });
-      // });
+      it('Navigate source file via structure tree', async () => {
+        log.debug('Navigate source file via structure tree');
+        // Wait the file tree to be rendered and click the 'src' folder on the file tree.
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeFileExplorerNode-src')).to.be(true);
+        });
+
+        await testSubjects.click('codeFileExplorerNode-src');
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeFileExplorerNode-models')).to.be(true);
+        });
+
+        await testSubjects.click('codeFileExplorerNode-models');
+        // Then the 'models' folder on the file tree.
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeFileExplorerNode-User.ts')).to.be(true);
+        });
+
+        await testSubjects.click('codeFileExplorerNode-User.ts');
+        // Then the 'User.ts' file on the file tree.
+        await retry.try(async () => {
+          expect(await testSubjects.exists('codeSourceViewer')).to.be(true);
+          expect(await testSubjects.exists('codeStructureTreeTab')).to.be(true);
+        });
+
+        // Click the structure tree tab
+        await testSubjects.click('codeStructureTreeTab');
+        await retry.tryForTime(300000, async () => {
+          expect(await testSubjects.exists('codeStructureTreeNode-User')).to.be(true);
+
+          await testSubjects.click('codeStructureTreeNode-User');
+          await retry.tryForTime(120000, async () => {
+            const currentUrl: string = await browser.getCurrentUrl();
+            log.info(`Jump to url: ${currentUrl}`);
+            expect(currentUrl.indexOf('src/models/User.ts!L92:6') > 0).to.be(true);
+          });
+        });
+      });
 
       it('goes to a repository which does not exist should render the 404 error page', async () => {
         log.debug('it goes to a repository which does not exist');
diff --git a/x-pack/test/functional/apps/code/history.ts b/x-pack/test/functional/apps/code/history.ts
index 75d004b2c4fa5..80a462f6508e3 100644
--- a/x-pack/test/functional/apps/code/history.ts
+++ b/x-pack/test/functional/apps/code/history.ts
@@ -24,7 +24,7 @@ export default function manageRepositoriesFunctionalTests({
   const PageObjects = getPageObjects(['common', 'header', 'security', 'code', 'home']);
 
   // FLAKY: https://github.com/elastic/kibana/issues/36495
-  describe.skip('History', () => {
+  describe('History', () => {
     const repositoryListSelector = 'codeRepositoryList codeRepositoryItem';
 
     describe('browser history can go back while exploring code app', () => {
@@ -200,22 +200,22 @@ export default function manageRepositoriesFunctionalTests({
         await PageObjects.common.sleep(5000);
         await testSubjects.click('codeStructureTreeTab');
         await retry.try(async () => {
-          const tabText = await (await find.byCssSelector('.euiTab-isSelected')).getVisibleText();
-          expect(tabText).to.equal('Structure');
+          // if structure tree tab is active, file tree tab's `data-test-subj` would be `codeFileTreeTab`
+          expect(testSubjects.exists('codeFileTreeTab')).to.be.ok();
         });
 
         await browser.goBack();
 
         await retry.try(async () => {
-          const tabText = await (await find.byCssSelector('.euiTab-isSelected')).getVisibleText();
-          expect(tabText).to.equal('File');
+          // if file tree tab is active, file tree tab's `data-test-subj` would be `codeFileTreeTabActive`
+          expect(testSubjects.exists('codeFileTreeTabActive')).to.be.ok();
         });
 
         await driver.navigate().forward();
 
         await retry.try(async () => {
-          const tabText = await (await find.byCssSelector('.euiTab-isSelected')).getVisibleText();
-          expect(tabText).to.equal('Structure');
+          // if structure tree tab is active, file tree tab's `data-test-subj` would be `codeFileTreeTab`
+          expect(testSubjects.exists('codeFileTreeTab')).to.be.ok();
         });
       });
     });