fix(nextjs): update e2e test case to cover env variables exported fro…

…m libraries

ISSUES CLOSED: nrwl#9633

e2e/next/src/next.test.ts

@@ -297,6 +297,50 @@ describe('Next.js Applications', () => {
     });
   }, 300000);
 
+  it('should display env values at runtime from a library', async () => {
+    const appName = uniq('app');
+    const libName = uniq('libName');
+
+    runCLI(`generate @nrwl/next:app ${appName} --no-interactive`);
+    runCLI(
+      `generate @nrwl/next:library ${libName} --no-component --no-interactive`
+    );
+
+    updateFile('.env.local', 'NX_CUSTOM_VAR=test value');
+    updateFile(
+      `libs/${libName}/src/index.ts`,
+      `
+    export const nxCustomEnvVar = () => {
+      return process.env['NX_CUSTOM_VAR'];
+    }
+    `
+    );
+
+    updateFile(
+      `apps/${appName}/pages/index.tsx`,
+      `
+      import React from 'react';
+      import { nxCustomEnvVar } from '@${proj}/${libName}';
+      
+      export const Index = () => {
+        return (
+        <p> {JSON.stringify(nxCustomEnvVar())} </p>
+        );
+      };
+      export default Index;
+      `
+    );
+
+    // serve Next.js
+    await runCommandUntil(`run ${appName}:serve`, (output) => {
+      return output.indexOf(`[ ready ] on http://localhost:4200`) > -1;
+    });
+
+    const pageData = await getData(4200, '/');
+
+    expect(pageData).toContain('test value');
+  }, 300000);
+
   it('should allow using a custom server implementation in TypeScript', async () => {
     const appName = uniq('app');
     const port = 4202;