Fix: Add compatibility for server-external-packages.jsonc in Next.js 16.0 canary+ by emulienfou · Pull Request #485 · vercel/workflow

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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vercel · 2025-12-02T14:31:41Z

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adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

vercel · 2025-12-02T14:31:41Z

@emulienfou is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

vercel · 2025-12-02T14:31:41Z

@emulienfou is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

vercel · 2025-12-02T14:31:41Z

@emulienfou is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

vercel · 2025-12-02T14:31:41Z

@emulienfou is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

vercel · 2025-12-02T14:31:41Z

@emulienfou is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

vercel · 2025-12-02T14:31:41Z

@emulienfou is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

emulienfou · 2025-12-02T14:31:31Z

Fixing:#422

Summary

This PR introduces a compatibility layer to correctly load the server-external-packages list across various Next.js versions, specifically addressing the change introduced in Next.js 16.1.0-canary and above.

Problem

Newer versions of Next.js (e.g., 16.1.0-canary+) have switched the file extension for server-external packages from .json to .jsonc (as noted in vercel/next.js#86252). This change causes a runtime error when trying to resolve the file in environments using older Next.js versions or when the file resolution is hardcoded to only look for .json.

Solution

A new utility function, loadServerExternalPackages(), has been implemented. This function ensures backward and forward compatibility by:

First, attempting to load the file with the newer .jsonc extension (next/dist/lib/server-external-packages.jsonc).
Second, if the .jsonc file is not found (indicating an older Next.js version), it falls back to loading the original .json extension (next/dist/lib/server-external-packages.json).

This prevents breaks for users running both older and cutting-edge versions of Next.js.

Supports both .jsonc (16.0-canary+) and .json (older versions)

changeset-bot · 2025-12-02T14:31:37Z

⚠️ No Changeset found

Latest commit: b365dd3

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

vercel · 2025-12-02T14:31:41Z

@emulienfou is attempting to deploy a commit to the Vercel Labs Team on Vercel.

A member of the Team first needs to authorize it.

adriandlam · 2025-12-02T19:48:12Z

+ return require(
+ require.resolve('next/dist/lib/server-external-packages.json')
+ );
+ }


need a fallback maybe?
Suggested change
}
}
return[];

@adriandlam Updated code to simplify try/catch block

is the JSON.parse(content) necessary? can we simplify the catch block alot more here? #497 seemed to pass before for nextjs-webpack (which is not canary).

…*.jsonc` file

…s fix issue for this next.js version and above

socket-security · 2025-12-02T20:00:28Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/tiny-jsonc@1.0.2
	npm/next@16.0.2-canary.29

View full report

emulienfou · 2025-12-03T22:14:16Z

Seems the fix was wrong, superseded by: #516

Loads server-external-packages from Next.js installation
edb1b58
Supports both .jsonc (16.0-canary+) and .json (older versions)

vercelBot reviewed Dec 2, 2025
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Comment threadpackages/next/src/index.ts

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adriandlam mentioned this pull request Dec 2, 2025
don't merge: tests for #485 #497
Closed

adriandlam reviewed Dec 2, 2025
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Comment threadpackages/next/src/index.ts Outdated

emulienfou added 2 commits December 2, 2025 14:58

Updating code following PR comments, using tiny-jsonc lib to load `…
e93985e
…*.jsonc` file

Updating next js to 16.0.2-canary.29 to run test E2E and check if thi…
2380c7b
…s fix issue for this next.js version and above

Simplify try/catch
b365dd3

emulienfou closed this Dec 3, 2025

emulienfou deleted the 12-02-server-external-packages-jsonc branch December 3, 2025 22:14