fix: HEAD request Content-Type for JS files in transform middleware by Copilot · Pull Request #11 · sapphi-red/vite

Copilot · 2025-07-18T03:29:06Z

Problem

HEAD requests to JavaScript files in the Vite dev server were returning incorrect Content-Type: text/html instead of text/javascript. This caused issues in environments where JavaScript file presence is checked via HEAD requests before loading, such as Module Federation setups.

Root Cause

The transform middleware only processed GET requests and immediately called next() for HEAD requests:

if (req.method !== 'GET' || knownIgnoreList.has(req.url!)) {
  return next()
}

This meant HEAD requests bypassed the transform middleware entirely and fell back to other middlewares that returned the default text/html content type.

Solution

1. Allow HEAD requests in transform middleware

Modified the HTTP method check to allow both GET and HEAD requests:

if ((req.method !== 'GET' && req.method !== 'HEAD') || knownIgnoreList.has(req.url!)) {
  return next()
}

2. Handle HEAD requests properly in send function

Updated the send function to handle HEAD requests by only sending headers without body content:

// For HEAD requests, don't send the body content
if (req.method === 'HEAD') {
  res.end()
} else {
  res.end(content)
}

Verification

HEAD requests to JS files now return Content-Type: text/javascript ✅
HEAD requests return the same headers as GET requests but without body content ✅
All existing functionality remains intact ✅
Pattern follows existing codebase conventions (similar to htmlFallback middleware) ✅

Testing

Added comprehensive tests to verify:

HEAD requests are processed by transform middleware
Correct Content-Type headers are returned
HEAD requests have empty body while GET requests have content
Non-GET/HEAD requests are still rejected appropriately

Closes vitejs#20415

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Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

packages/vite/src/node/server/middlewares/__tests__/transform-integration.spec.ts

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

playground/resolve/__tests__/resolve.spec.ts

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

packages/vite/src/node/server/middlewares/__tests__/transform.spec.ts

packages/vite/src/node/server/send.ts

playground/resolve/__tests__/resolve.spec.ts

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

Copilot · 2025-07-18T04:30:28Z

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

vite.dev
- Triggering command: /home/REDACTED/.cache/playwright-bin/chromium_headless_shell-1181/chrome-linux/headless_shell --disable-field-trial-config --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-back-forward-cache --disable-breakpad --disable-client-side-phishing-detection --disable-component-extensions-with-REDACTED-pages --disable-component-update --no-default-browser-check --disable-default-apps --disable-dev-shm-usage --disable-extensions --disable-features=AcceptCHFrame,AutoExpandDetailsElement,AvoidUnnecessaryBeforeUnloadCheckSync,CertificateTransparencyComponentUpdater,DestroyProfileOnBrowserClose,DialMediaRouteProvider,ExtensionManifestV2Disabled,GlobalMediaControls,HttpsUpgrades,ImprovedCookieControls,LazyFrameLoading,LensOverlay,MediaRouter,PaintHolding,ThirdPartyStoragePartitioning,Translate --allow-pre-commit-input --disable-hang-monitor --disable-ipc-flooding-protection --disable-popup-blocking --disable-prompt-on-repost --disable-renderer-REDACTEDing --force-color-profile=srgb --metrics-recording-only --no-first-run --password-store=basic --use-mock-keychain --no-service-autorun --export-tagged-pdf --disable-search-engine-choice-screen --unsafely-disable-devtools-self-xss-warnings --edge-skip-compat-layer-relaunch --enable-automation --headless --hide-scrollbars --mute-audio --blink-settings=primaryHoverType=2,availableHoverTypes=2,primaryPointerType=4,availablePointerTypes=4 --no-sandbox --no-sandbox --disable-setuid-sandbox --user-data-dir=/tmp/playwright_chromiumdev_profile-l2YqN9 --remote-debugging-pipe --no-startup-window (dns block)
- Triggering command: /home/REDACTED/.cache/playwright-bin/chromium_headless_shell-1181/chrome-linux/headless_shell --disable-field-trial-config --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-back-forward-cache --disable-breakpad --disable-client-side-phishing-detection --disable-component-extensions-with-REDACTED-pages --disable-component-update --no-default-browser-check --disable-default-apps --disable-dev-shm-usage --disable-extensions --disable-features=AcceptCHFrame,AutoExpandDetailsElement,AvoidUnnecessaryBeforeUnloadCheckSync,CertificateTransparencyComponentUpdater,DestroyProfileOnBrowserClose,DialMediaRouteProvider,ExtensionManifestV2Disabled,GlobalMediaControls,HttpsUpgrades,ImprovedCookieControls,LazyFrameLoading,LensOverlay,MediaRouter,PaintHolding,ThirdPartyStoragePartitioning,Translate --allow-pre-commit-input --disable-hang-monitor --disable-ipc-flooding-protection --disable-popup-blocking --disable-prompt-on-repost --disable-renderer-REDACTEDing --force-color-profile=srgb --metrics-recording-only --no-first-run --password-store=basic --use-mock-keychain --no-service-autorun --export-tagged-pdf --disable-search-engine-choice-screen --unsafely-disable-devtools-self-xss-warnings --edge-skip-compat-layer-relaunch --enable-automation --headless --hide-scrollbars --mute-audio --blink-settings=primaryHoverType=2,availableHoverTypes=2,primaryPointerType=4,availablePointerTypes=4 --no-sandbox --no-sandbox --disable-setuid-sandbox --user-data-dir=/tmp/playwright_chromiumdev_profile-ABag6x --remote-debugging-pipe --no-startup-window (dns block)
- Triggering command: /home/REDACTED/.cache/playwright-bin/chromium_headless_shell-1181/chrome-linux/headless_shell --disable-field-trial-config --disable-REDACTED-networking --disable-REDACTED-timer-throttling --disable-REDACTEDing-occluded-windows --disable-back-forward-cache --disable-breakpad --disable-client-side-phishing-detection --disable-component-extensions-with-REDACTED-pages --disable-component-update --no-default-browser-check --disable-default-apps --disable-dev-shm-usage --disable-extensions --disable-features=AcceptCHFrame,AutoExpandDetailsElement,AvoidUnnecessaryBeforeUnloadCheckSync,CertificateTransparencyComponentUpdater,DestroyProfileOnBrowserClose,DialMediaRouteProvider,ExtensionManifestV2Disabled,GlobalMediaControls,HttpsUpgrades,ImprovedCookieControls,LazyFrameLoading,LensOverlay,MediaRouter,PaintHolding,ThirdPartyStoragePartitioning,Translate --allow-pre-commit-input --disable-hang-monitor --disable-ipc-flooding-protection --disable-popup-blocking --disable-prompt-on-repost --disable-renderer-REDACTEDing --force-color-profile=srgb --metrics-recording-only --no-first-run --password-store=basic --use-mock-keychain --no-service-autorun --export-tagged-pdf --disable-search-engine-choice-screen --unsafely-disable-devtools-self-xss-warnings --edge-skip-compat-layer-relaunch --enable-automation --headless --hide-scrollbars --mute-audio --blink-settings=primaryHoverType=2,availableHoverTypes=2,primaryPointerType=4,availablePointerTypes=4 --no-sandbox --no-sandbox --disable-setuid-sandbox --user-data-dir=/tmp/playwright_chromiumdev_profile-m4oOzk --remote-debugging-pipe --no-startup-window (dns block)
workers.cloudflare.com
- Triggering command: node (vitest 1) (dns block)
- Triggering command: node (vitest 3) (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to my firewall allow list

playground/resolve/__tests__/resolve.spec.ts

sapphi-red · 2025-07-18T05:23:08Z

=> vitejs#20421

sapphi-red and others added 2 commits July 18, 2025 12:00

chore: add copilot agent configs

09612fc

Initial plan

52514d5

Copilot AI assigned Copilot and sapphi-red Jul 18, 2025

Copilot started work on behalf of sapphi-red July 18, 2025 03:29 View session

Copilot AI and others added 2 commits July 18, 2025 03:42

Fix HEAD request Content-Type for JS files in transform middleware

d88195a

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

Update tests to be more reliable and fix integration test setup

7a1fc7d

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] @vitejs/vite/issues/20415 Fix this issue. Make sure to write a test for it. The related line should be @vitejs/vite/files/packages/vite/src/node/server/middlewares/transform.ts~~ fix: HEAD request Content-Type for JS files in transform middleware Jul 18, 2025

Copilot AI requested a review from sapphi-red July 18, 2025 03:47

Copilot finished work on behalf of sapphi-red July 18, 2025 03:47

sapphi-red reviewed Jul 18, 2025

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packages/vite/src/node/server/middlewares/__tests__/transform-integration.spec.ts Outdated Show resolved Hide resolved

Copilot started work on behalf of sapphi-red July 18, 2025 03:48 View session

Move HEAD request tests from middleware unit tests to resolve e2e tests

c4638d5

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

Copilot AI requested a review from sapphi-red July 18, 2025 03:55

Copilot finished work on behalf of sapphi-red July 18, 2025 03:55

sapphi-red requested changes Jul 18, 2025

View reviewed changes

Copilot started work on behalf of sapphi-red July 18, 2025 04:09 View session

refactor: address feedback on HEAD request tests

6443766

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

Copilot finished work on behalf of sapphi-red July 18, 2025 04:17

Copilot AI requested a review from sapphi-red July 18, 2025 04:17

sapphi-red requested changes Jul 18, 2025

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Copilot started work on behalf of sapphi-red July 18, 2025 04:21 View session

address feedback: remove test file, clean up comments and tests

8faeb85

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>

Copilot AI requested a review from sapphi-red July 18, 2025 04:30

Copilot finished work on behalf of sapphi-red July 18, 2025 04:30

sapphi-red reviewed Jul 18, 2025

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Copilot AI requested a review from sapphi-red July 18, 2025 05:00

Copilot stopped work on behalf of sapphi-red due to an error July 18, 2025 05:00
Copilot has encountered an error. See logs for additional details.

sapphi-red force-pushed the main branch from 09612fc to 27a192f Compare July 18, 2025 05:15

This was referenced Jul 18, 2025

fix: respond with correct headers and status code for HEAD requests vitejs/vite#20421

Merged

chore: add copilot agent configs vitejs/vite#20422

Merged

sapphi-red closed this Jul 18, 2025

sapphi-red deleted the copilot/fix-4698c672-67fb-40e7-af5b-229b906d1ae9 branch July 18, 2025 05:23

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fix: HEAD request Content-Type for JS files in transform middleware#11

fix: HEAD request Content-Type for JS files in transform middleware#11
Copilot wants to merge 8 commits intomainfrom
copilot/fix-4698c672-67fb-40e7-af5b-229b906d1ae9

Copilot AI commented Jul 18, 2025 •

edited

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Copilot AI commented Jul 18, 2025

I tried to connect to the following addresses, but was blocked by firewall rules:

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sapphi-red commented Jul 18, 2025

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Copilot AI commented Jul 18, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Problem

Root Cause

Solution

1. Allow HEAD requests in transform middleware

2. Handle HEAD requests properly in send function

Verification

Testing

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Copilot AI commented Jul 18, 2025

I tried to connect to the following addresses, but was blocked by firewall rules:

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sapphi-red commented Jul 18, 2025

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Copilot AI commented Jul 18, 2025 •

edited

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