Adds inline script functionality to next/script for worker and beforeInteractive strategies

docs/basic-features/script.md

@@ -243,10 +243,7 @@ Or by using the `dangerouslySetInnerHTML` property:
 />
 ```
 
-There are two limitations to be aware of when using the Script component for inline scripts:
-
-- Only the `afterInteractive` and `lazyOnload` strategies can be used. The `beforeInteractive` loading strategy injects the contents of an external script into the initial HTML response. Inline scripts already do this, which is why **the `beforeInteractive` strategy cannot be used with inline scripts.**
-- An `id` attribute must be defined in order for Next.js to track and optimize the script
+The `id` property is required for **inline scripts** in order for Next.js to track and optimize the script.
 
 ### Executing Code After Loading (`onLoad`)
 

errors/invalid-script.md

@@ -0,0 +1,38 @@
+# Invalid Script
+
+#### Why This Error Occurred
+
+Somewhere in your application, you are using the `next/script` component without including an inline script or `src` attribute.
+
+#### Possible Ways to Fix It
+
+Look for any usage of the `next/script` component and make sure that `src` is provided or an inline script is used.
+
+**Compatible `src` attribute**
+
+```jsx
+<Script src="https://example.com/analytics.js" />
+```
+
+**Compatible inline script with curly braces**
+
+```jsx
+<Script id="show-banner">
+  {`document.getElementById('banner').classList.remove('hidden')`}
+</Script>
+```
+
+**Compatible inline script with `dangerouslySetInnerHtml`**
+
+```jsx
+<Script
+  id="show-banner"
+  dangerouslySetInnerHTML={{
+    __html: `document.getElementById('banner').classList.remove('hidden')`,
+  }}
+/>
+```
+
+### Useful Links
+
+- [Script Component in Documentation](https://nextjs.org/docs/basic-features/script)

errors/manifest.json

@@ -657,6 +657,10 @@
         {
           "title": "no-assign-module-variable",
           "path": "/errors/no-assign-module-variable.md"
+        },
+        {
+          "title": "invalid-script",
+          "path": "/errors/invalid-script.md"
         }
       ]
     }

packages/next/client/script.tsx

@@ -149,7 +149,6 @@ function Script(props: ScriptProps): JSX.Element | null {
   const {
     src = '',
     onLoad = () => {},
-    dangerouslySetInnerHTML,
     strategy = 'afterInteractive',
     onError,
     ...restProps

packages/next/pages/_document.tsx

@@ -121,12 +121,54 @@ function getPreNextWorkerScripts(context: HtmlProps, props: OriginProps) {
           }}
         />
         {(scriptLoader.worker || []).map((file: ScriptProps, index: number) => {
-          const { strategy, ...scriptProps } = file
+          const {
+            strategy,
+            src,
+            children: scriptChildren,
+            dangerouslySetInnerHTML,
+            ...scriptProps
+          } = file
+
+          let srcProps: {
+            src?: string
+            dangerouslySetInnerHTML?: {
+              __html: string
+            }
+          } = {}
+
+          if (src) {
+            // Use external src if provided
+            srcProps.src = src
+          } else if (
+            dangerouslySetInnerHTML &&
+            dangerouslySetInnerHTML.__html
+          ) {
+            // Embed inline script if provided with dangerouslySetInnerHTML
+            srcProps.dangerouslySetInnerHTML = {
+              __html: dangerouslySetInnerHTML.__html,
+            }
+          } else if (scriptChildren) {
+            // Embed inline script if provided with children
+            srcProps.dangerouslySetInnerHTML = {
+              __html:
+                typeof scriptChildren === 'string'
+                  ? scriptChildren
+                  : Array.isArray(scriptChildren)
+                  ? scriptChildren.join('')
+                  : '',
+            }
+          } else {
+            throw new Error(
+              'Invalid usage of next/script. Did you forget to include a src attribute or an inline script? https://nextjs.org/docs/messages/invalid-script'
+            )
+          }
+
           return (
             <script
+              {...srcProps}
               {...scriptProps}
               type="text/partytown"
-              key={scriptProps.src || index}
+              key={src || index}
               nonce={props.nonce}
               data-nscript="worker"
               crossOrigin={props.crossOrigin || crossOrigin}
@@ -137,9 +179,7 @@ function getPreNextWorkerScripts(context: HtmlProps, props: OriginProps) {
     )
   } catch (err) {
     if (isError(err) && err.code !== 'MODULE_NOT_FOUND') {
-      console.warn(
-        `Warning: Partytown could not be instantiated in your application due to an error. ${err.message}`
-      )
+      console.warn(`Warning: ${err.message}`)
     }
     return null
   }
@@ -150,8 +190,9 @@ function getPreNextScripts(context: HtmlProps, props: OriginProps) {
 
   const webWorkerScripts = getPreNextWorkerScripts(context, props)
 
-  const beforeInteractiveScripts = (scriptLoader.beforeInteractive || []).map(
-    (file: ScriptProps, index: number) => {
+  const beforeInteractiveScripts = (scriptLoader.beforeInteractive || [])
+    .filter((script) => script.src)
+    .map((file: ScriptProps, index: number) => {
       const { strategy, ...scriptProps } = file
       return (
         <script
@@ -163,8 +204,7 @@ function getPreNextScripts(context: HtmlProps, props: OriginProps) {
           crossOrigin={props.crossOrigin || crossOrigin}
         />
       )
-    }
-  )
+    })
 
   return (
     <>
@@ -500,6 +540,44 @@ export class Head extends Component<
     ]
   }
 
+  getBeforeInteractiveInlineScripts() {
+    const { scriptLoader } = this.context
+    const { nonce, crossOrigin } = this.props
+
+    return (scriptLoader.beforeInteractive || [])
+      .filter(
+        (script) =>
+          !script.src && (script.dangerouslySetInnerHTML || script.children)
+      )
+      .map((file: ScriptProps, index: number) => {
+        const { strategy, children, dangerouslySetInnerHTML, ...scriptProps } =
+          file
+        let html = ''
+
+        if (dangerouslySetInnerHTML && dangerouslySetInnerHTML.__html) {
+          html = dangerouslySetInnerHTML.__html
+        } else if (children) {
+          html =
+            typeof children === 'string'
+              ? children
+              : Array.isArray(children)
+              ? children.join('')
+              : ''
+        }
+
+        return (
+          <script
+            {...scriptProps}
+            dangerouslySetInnerHTML={{ __html: html }}
+            key={scriptProps.id || index}
+            nonce={nonce}
+            data-nscript="beforeInteractive"
+            crossOrigin={crossOrigin || process.env.__NEXT_CROSS_ORIGIN}
+          />
+        )
+      })
+  }
+
   getDynamicChunks(files: DocumentFiles) {
     return getDynamicChunks(this.context, this.props, files)
   }
@@ -782,6 +860,7 @@ export class Head extends Component<
                 href={canonicalBase + getAmpPath(ampPath, dangerousAsPath)}
               />
             )}
+            {this.getBeforeInteractiveInlineScripts()}
             {!optimizeCss && this.getCssLinks(files)}
             {!optimizeCss && <noscript data-n-css={this.props.nonce ?? ''} />}
 

test/e2e/next-script-worker-strategy/index.test.ts

@@ -51,7 +51,7 @@ describe('experimental.nextScriptWorkers: false with no Partytown dependency', (
   })
 })
 
-describe('experimental.nextScriptWorkers: true with required Partytown dependency', () => {
+describe('experimental.nextScriptWorkers: true with required Partytown dependency for external script', () => {
   let next: NextInstance
 
   beforeAll(async () => {
@@ -139,6 +139,102 @@ describe('experimental.nextScriptWorkers: true with required Partytown dependenc
   })
 })
 
+describe('experimental.nextScriptWorkers: true with required Partytown dependency for inline script', () => {
+  const createNextApp = async (script) =>
+    await createNext({
+      nextConfig: {
+        experimental: {
+          nextScriptWorkers: true,
+        },
+        dependencies: {
+          react: '17',
+          'react-dom': '17',
+        },
+      },
+      files: {
+        'pages/index.js': `
+        import Script from 'next/script'
+      
+        export default function Page() {
+          return (
+            <>
+              ${script}
+              <div id="text" />
+            </>
+          )
+        }
+      `,
+      },
+      dependencies: {
+        '@builder.io/partytown': '0.4.2',
+      },
+    })
+
+  it('Inline worker script through children is modified by Partytown to execute on a worker thread', async () => {
+    let next: NextInstance
+    let browser: BrowserInterface
+
+    next = await createNextApp(
+      `<Script id="inline-script" strategy="worker">{"document.getElementById('text').textContent += 'abc'"}</Script>`
+    )
+
+    try {
+      browser = await webdriver(next.url, '/')
+
+      const predefinedWorkerScripts = await browser.eval(
+        `document.querySelectorAll('script[type="text/partytown"]').length`
+      )
+      expect(predefinedWorkerScripts).toEqual(1)
+
+      await waitFor(1000)
+
+      // Partytown modifes type to "text/partytown-x" after it has been executed in the web worker
+      const processedWorkerScripts = await browser.eval(
+        `document.querySelectorAll('script[type="text/partytown-x"]').length`
+      )
+      expect(processedWorkerScripts).toEqual(1)
+
+      const text = await browser.elementById('text').text()
+      expect(text).toBe('abc')
+    } finally {
+      if (browser) await browser.close()
+      await next.destroy()
+    }
+  })
+
+  it('Inline worker script through dangerouslySetInnerHtml is modified by Partytown to execute on a worker thread', async () => {
+    let next: NextInstance
+    let browser: BrowserInterface
+
+    next = await createNextApp(
+      `<Script id="inline-script" strategy="worker" dangerouslySetInnerHTML={{__html: "document.getElementById('text').textContent += 'abcd'"}}/>`
+    )
+
+    try {
+      browser = await webdriver(next.url, '/')
+
+      const predefinedWorkerScripts = await browser.eval(
+        `document.querySelectorAll('script[type="text/partytown"]').length`
+      )
+      expect(predefinedWorkerScripts).toEqual(1)
+
+      await waitFor(1000)
+
+      // Partytown modifes type to "text/partytown-x" after it has been executed in the web worker
+      const processedWorkerScripts = await browser.eval(
+        `document.querySelectorAll('script[type="text/partytown-x"]').length`
+      )
+      expect(processedWorkerScripts).toEqual(1)
+
+      const text = await browser.elementById('text').text()
+      expect(text).toBe('abcd')
+    } finally {
+      if (browser) await browser.close()
+      await next.destroy()
+    }
+  })
+})
+
 describe('experimental.nextScriptWorkers: true with config override', () => {
   let next: NextInstance
 

test/integration/script-loader/base/pages/_document.js

@@ -16,6 +16,13 @@ export default function Document() {
           src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.20/lodash.min.js?a=scriptBeforeInteractive"
           strategy="beforeInteractive"
         ></Script>
+        <Script
+          id="inline-before"
+          strategy="beforeInteractive"
+          dangerouslySetInnerHTML={{
+            __html: `console.log('inline beforeInteractive')`,
+          }}
+        ></Script>
       </Head>
       <body>
         <Main />

test/integration/script-loader/test/index.test.js

@@ -190,6 +190,19 @@ describe('Next.js Script - Primary Strategies', () => {
     }
   })
 
+  it('priority beforeInteractive with inline script', async () => {
+    const html = await renderViaHTTP(appPort, '/page5')
+    const $ = cheerio.load(html)
+
+    const script = $('#inline-before')
+    expect(script.length).toBe(1)
+
+    // Script is inserted before CSS
+    expect(
+      $(`#inline-before ~ link[href^="/_next/static/css"]`).length
+    ).toBeGreaterThan(0)
+  })
+
   it('Does not duplicate inline scripts', async () => {
     let browser
     try {