import { isNextDev, nextTestSetup } from 'e2e-utils' import { waitForNoRedbox } from 'next-test-utils' describe('Validations for ', () => { const { next, isNextDeploy } = nextTestSetup({ files: __dirname, skipDeployment: true, }) if (isNextDeploy) { return it('should skip deploy', () => {}) } let previousOutputIndex beforeEach(() => { previousOutputIndex = next.cliOutput.length }) function newConsoleOutput() { return next.cliOutput.slice(previousOutputIndex) } describe('When rendering from a Server Component', () => { describe('Rendering directly', () => { it('warns if the child is a synchronous server component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-link/synchronous' ) if (isNextDev) { await expect(browser).toDisplayCollapsedRedbox(` [ { "code": "E394", "description": "Using a Server Component as a direct child of \`\` is not supported. If you need legacyBehavior, wrap your Server Component in a Client Component that renders the Link's \`\` tag.", "environmentLabel": "Prerender", "label": "Console Error", "source": "app/validations/rsc-that-renders-link/synchronous/page.tsx (7:7) @ Page > 7 | | ^", "stack": [ "Page app/validations/rsc-that-renders-link/synchronous/page.tsx (7:7)", ], }, { "code": "E394", "description": "\`legacyBehavior\` is deprecated and will be removed in a future release. A codemod is available to upgrade your components: npx @next/codemod@latest new-link . Learn more: https://nextjs.org/docs/app/building-your-application/upgrading/codemods#remove-a-tags-from-link-components", "environmentLabel": null, "label": "Console Error", "source": "app/validations/rsc-that-renders-link/synchronous/page.tsx (7:7) @ Page > 7 | | ^", "stack": [ "Page app/validations/rsc-that-renders-link/synchronous/page.tsx (7:7)", ], }, ] `) } else { expect(newConsoleOutput()).toMatchInlineSnapshot(` "Using a Server Component as a direct child of \`\` is not supported. If you need legacyBehavior, wrap your Server Component in a Client Component that renders the Link's \`\` tag. " `) } }) it('warns and throws an error if the child is an asynchronous server component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-link/asynchronous' ) if (isNextDev) { await expect(browser).toDisplayRedbox(` [ { "code": "E394", "description": "Using a Server Component as a direct child of \`\` is not supported. If you need legacyBehavior, wrap your Server Component in a Client Component that renders the Link's \`\` tag.", "environmentLabel": "Prerender", "label": "Console Error", "source": "app/validations/rsc-that-renders-link/asynchronous/page.tsx (7:7) @ Page > 7 | | ^", "stack": [ "Page app/validations/rsc-that-renders-link/asynchronous/page.tsx (7:7)", ], }, { "code": "E863", "description": "\`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag.", "environmentLabel": null, "label": "Runtime Error", "source": "app/validations/rsc-that-renders-link/asynchronous/page.tsx (7:7) @ Page > 7 | | ^", "stack": [ "Page app/validations/rsc-that-renders-link/asynchronous/page.tsx (7:7)", ], }, ] `) } else { const output = getContentBetween({ input: newConsoleOutput(), endContent: ' at', }) expect(output).toMatchInlineSnapshot(` "Using a Server Component as a direct child of \`\` is not supported. If you need legacyBehavior, wrap your Server Component in a Client Component that renders the Link's \`\` tag. ⨯ Error: \`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag." `) } }) it('does not warn or throw if you pass a client component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-link/client' ) if (isNextDev) { await waitForNoRedbox(browser) } else { expect(newConsoleOutput()).toEqual('') } }) it('does not warn or throw if you pass a server component into a client component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-link/client-with-rsc-child' ) if (isNextDev) { await waitForNoRedbox(browser) } else { expect(newConsoleOutput()).toEqual('') } }) it('warns if the child is a lazy component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-link/lazy' ) if (isNextDev) { await expect(browser).toDisplayRedbox(` [ { "code": "E394", "description": "Using a Lazy Component as a direct child of \`\` from a Server Component is not supported. If you need legacyBehavior, wrap your Lazy Component in a Client Component that renders the Link's \`\` tag.", "environmentLabel": "Prerender", "label": "Console Error", "source": "app/validations/rsc-that-renders-link/lazy/page.tsx (9:7) @ Page > 9 | | ^", "stack": [ "Page app/validations/rsc-that-renders-link/lazy/page.tsx (9:7)", ], }, { "code": "E863", "description": "\`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag.", "environmentLabel": null, "label": "Runtime Error", "source": "app/validations/rsc-that-renders-link/lazy/page.tsx (9:7) @ Page > 9 | | ^", "stack": [ "Page app/validations/rsc-that-renders-link/lazy/page.tsx (9:7)", ], }, ] `) } else { const output = getContentBetween({ input: newConsoleOutput(), endContent: ' at', }) expect(output).toMatchInlineSnapshot(` "Using a Lazy Component as a direct child of \`\` from a Server Component is not supported. If you need legacyBehavior, wrap your Lazy Component in a Client Component that renders the Link's \`\` tag. ⨯ Error: \`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag." `) } }) }) describe('Rendering a Client Component that renders ', () => { it('does not warn if the child is a synchronous server component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-client/synchronous' ) if (isNextDev) { await waitForNoRedbox(browser) } else { expect(newConsoleOutput()).toEqual('') } }) it('throws an error if the child is an asynchronous server component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-client/asynchronous' ) if (isNextDev) { await expect(browser).toDisplayRedbox(` { "code": "E863", "description": "\`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag.", "environmentLabel": null, "label": "Runtime Error", "source": "app/validations/rsc-that-renders-client/client-link.tsx (7:10) @ ClientLink > 7 | return | ^", "stack": [ "ClientLink app/validations/rsc-that-renders-client/client-link.tsx (7:10)", "Page app/validations/rsc-that-renders-client/asynchronous/page.tsx (7:7)", ], } `) } else { const output = getContentBetween({ input: newConsoleOutput(), endContent: ' at', }) expect(output).toMatchInlineSnapshot( `"⨯ Error: \`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag."` ) } }) it('does not warn or throw if you pass a client component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-client/client' ) if (isNextDev) { await waitForNoRedbox(browser) } else { expect(newConsoleOutput()).toEqual('') } }) it('does not warn or throw if you pass a server component into a client component', async () => { const browser = await next.browser( '/validations/rsc-that-renders-client/client-with-rsc-child' ) if (isNextDev) { await waitForNoRedbox(browser) } else { expect(newConsoleOutput()).toEqual('') } }) }) }) describe('When rendering from a Client Component', () => { it('errors if there are no children', async () => { const browser = await next.browser('/validations/client/missing-child') if (isNextDev) { await expect(browser).toDisplayRedbox(` { "code": "E320", "description": "No children were passed to with \`href\` of \`/about\` but one child is required https://nextjs.org/docs/messages/link-no-children", "environmentLabel": null, "label": "Runtime Error", "source": "app/validations/client/missing-child/page.tsx (6:10) @ Page > 6 | return | ^", "stack": [ "Page app/validations/client/missing-child/page.tsx (6:10)", ], } `) } else { const output = getContentBetween({ input: newConsoleOutput(), endContent: ' at', }) expect(output).toMatchInlineSnapshot( `"⨯ Error: React.Children.only expected to receive a single React element child."` ) } }) it('errors if there are multiple children', async () => { const browser = await next.browser( '/validations/client/multiple-children' ) if (isNextDev) { await expect(browser).toDisplayRedbox(` { "code": "E266", "description": "Multiple children were passed to with \`href\` of \`/about\` but only one child is supported https://nextjs.org/docs/messages/link-multiple-children Open your browser's console to view the Component stack trace.", "environmentLabel": null, "label": "Runtime Error", "source": "app/validations/client/multiple-children/page.tsx (7:5) @ Page > 7 | | ^", "stack": [ "Page app/validations/client/multiple-children/page.tsx (7:5)", ], } `) } else { const output = getContentBetween({ input: newConsoleOutput(), endContent: ' at', }) expect(output).toMatchInlineSnapshot( `"⨯ Error: React.Children.only expected to receive a single React element child."` ) } }) it('does not warn or throw if you pass a child component', async () => { const browser = await next.browser('/validations/client/child-component') if (isNextDev) { await waitForNoRedbox(browser) } else { expect(newConsoleOutput()).toEqual('') } }) it('warns and throws an error if the child is lazy JSX', async () => { const browser = await next.browser('/validations/client/lazy-jsx') if (isNextDev) { await expect(browser).toDisplayRedbox(` { "code": "E863", "description": "\`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag.", "environmentLabel": null, "label": "Runtime Error", "source": "app/validations/client/lazy-jsx/page.tsx (9:7) @ Page > 9 | | ^", "stack": [ "Page app/validations/client/lazy-jsx/page.tsx (9:7)", ], } `) } else { const output = getContentBetween({ input: newConsoleOutput(), endContent: ' at', }) expect(output).toMatchInlineSnapshot( `"⨯ Error: \`\` received a direct child that is either a Server Component, or JSX that was loaded with React.lazy(). This is not supported. Either remove legacyBehavior, or make the direct child a Client Component that renders the Link's \`\` tag."` ) } }) }) }) function getContentBetween({ input, startContent, endContent, }: { input: string startContent?: string endContent?: string }): string { const lines = input.split('\n') const startIdx = startContent ? lines.findIndex((line) => line.includes(startContent)) : -1 const endIdx = endContent ? lines.findIndex((line) => line.includes(endContent)) : -1 if (startContent && startIdx < 0) return '' if (endContent && endIdx >= 0 && endIdx <= startIdx) return '' const sliceStart = startIdx >= 0 ? startIdx + 1 : 0 const sliceEnd = endIdx > sliceStart ? endIdx : undefined return lines.slice(sliceStart, sliceEnd).join('\n') }