[Blazor] Remove sourcemap link comments from production bundles for blazor.web.js and blazor.webassembly.js #62558

Copilot · 2025-07-03T15:33:45Z

This change modifies the Rollup configuration to generate sourcemap files without including sourcemap link comments in production bundles for blazor.web.js and blazor.webassembly.js.

Changes Made

Modified src/Components/Web.JS/rollup.config.mjs to use sourcemap: 'hidden' for production builds of blazor.web.js and blazor.webassembly.js
This generates .map files but omits the //# sourceMappingURL= comments from the bundle
Preserves existing behavior for other bundles:
- blazor.server.js still gets sourcemap link comments (sourcemap: true)
- blazor.webview.js still gets inline sourcemaps (sourcemap: 'inline')
- All development builds continue to include sourcemap link comments

Behavior

Before:

// Production blazor.web.js would end with:
console.log('Blazor initialized');
//# sourceMappingURL=blazor.web.js.map

After:

// Production blazor.web.js now ends with:
console.log('Blazor initialized');
// No sourcemap link comment

The sourcemap files (blazor.web.js.map, blazor.webassembly.js.map) are still generated and contain full debugging information. Developers can manually load these sourcemaps in browser dev tools when needed.

Benefits

Reduces production bundle size by eliminating sourcemap URL comments
Maintains debugging capability through manually loadable sourcemap files
Aligns with security best practices by not exposing sourcemap URLs in production
Consistent with the related .NET runtime issue approach

Fixes #62295.

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:

googlechromelabs.github.io
- Triggering command: node install.mjs (dns block)
https://storage.googleapis.com/chrome-for-testing-public/134.0.6998.35/linux64/chrome-headless-shell-linux64.zip
- Triggering command: node install.mjs (http 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

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.

…nd blazor.webassembly.js Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>

javiercn · 2025-07-03T15:55:54Z

src/Components/Web.JS/package.json

@@ -23,7 +23,7 @@
    "@babel/core": "^7.23.6",
    "@babel/preset-env": "^7.23.6",
    "@babel/preset-typescript": "^7.23.3",
-    "@microsoft/dotnet-js-interop": "*",
+    "@microsoft/dotnet-js-interop": "^10.0.0-dev",


Do not change this

Reverted the unintended change to the @microsoft/dotnet-js-interop dependency. The package.json now maintains the original "*" version. The main fix for the sourcemap issue remains in rollup.config.mjs only.

Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>

lewing

is the remaining package-lock change intended?

javiercn · 2025-07-08T23:04:40Z

package-lock.json

@@ -18343,7 +18343,7 @@
        "@babel/core": "^7.23.6",
        "@babel/preset-env": "^7.23.6",
        "@babel/preset-typescript": "^7.23.3",
-        "@microsoft/dotnet-js-interop": "*",
+        "@microsoft/dotnet-js-interop": "^10.0.0-dev",


@copilot

Undo this change too.

Reverted the package-lock.json changes in commit 6d9e1e4.

javiercn

@copilot get back to work!

Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>

Copilot · 2025-07-08T23:08:33Z

is the remaining package-lock change intended?

No, the package-lock.json change was unintended. I've reverted it in commit 6d9e1e4.

Copilot · 2025-07-08T23:15:23Z

@copilot get back to work!

All feedback has been addressed! The sourcemap fix is implemented in rollup.config.mjs (commit 9dcc7e5), and the unintended changes to package.json and package-lock.json have been reverted (commits bf26c4a and 6d9e1e4).

Initial plan

d27f7e4

Copilot AI assigned Copilot and javiercn Jul 3, 2025

Copilot started work on behalf of javiercn July 3, 2025 15:33 View session

dotnet-policy-service bot added the Attention: Shared Code Modified label Jul 3, 2025

Fix sourcemap link comments in production bundles for blazor.web.js a…

9dcc7e5

…nd blazor.webassembly.js Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] [Blazor] Do not emit sourcemap link comment on production bundles for blazor.web.js and blazor.webassembly.js~~ [Blazor] Remove sourcemap link comments from production bundles for blazor.web.js and blazor.webassembly.js Jul 3, 2025

Copilot AI requested a review from javiercn July 3, 2025 15:46

Copilot finished work on behalf of javiercn July 3, 2025 15:46

javiercn reviewed Jul 3, 2025

View reviewed changes

Copilot started work on behalf of javiercn July 3, 2025 15:56 View session

Revert unintended package.json dependency change

bf26c4a

Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>

Copilot AI requested a review from javiercn July 3, 2025 16:00

Copilot finished work on behalf of javiercn July 3, 2025 16:00

javiercn marked this pull request as ready for review July 3, 2025 17:52

javiercn requested a review from a team as a code owner July 3, 2025 17:52

lewing approved these changes Jul 8, 2025

View reviewed changes

javiercn reviewed Jul 8, 2025

View reviewed changes

Copilot started work on behalf of javiercn July 8, 2025 23:04 View session

javiercn reviewed Jul 8, 2025

View reviewed changes

Revert unintended package-lock.json changes

6d9e1e4

Co-authored-by: javiercn <6995051+javiercn@users.noreply.github.com>

Copilot AI requested a review from javiercn July 8, 2025 23:09

Copilot finished work on behalf of javiercn July 8, 2025 23:09

Copilot started work on behalf of javiercn July 8, 2025 23:09 View session

Copilot finished work on behalf of javiercn July 8, 2025 23:15

javiercn merged commit 238af05 into main Jul 9, 2025
29 checks passed

javiercn deleted the copilot/fix-62295 branch July 9, 2025 16:05

dotnet-policy-service bot added this to the 10.0-preview7 milestone Jul 9, 2025

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[Blazor] Remove sourcemap link comments from production bundles for blazor.web.js and blazor.webassembly.js #62558

[Blazor] Remove sourcemap link comments from production bundles for blazor.web.js and blazor.webassembly.js #62558

Copilot AI commented Jul 3, 2025 •

edited

Loading

Uh oh!

javiercn Jul 3, 2025

Uh oh!

Copilot AI Jul 3, 2025

Uh oh!

lewing left a comment

Uh oh!

javiercn Jul 8, 2025

Uh oh!

Copilot AI Jul 8, 2025

Uh oh!

javiercn left a comment

Uh oh!

Copilot AI commented Jul 8, 2025

Uh oh!

Copilot AI commented Jul 8, 2025

Uh oh!

Uh oh!

Uh oh!

[Blazor] Remove sourcemap link comments from production bundles for blazor.web.js and blazor.webassembly.js #62558

[Blazor] Remove sourcemap link comments from production bundles for blazor.web.js and blazor.webassembly.js #62558

Conversation

Copilot AI commented Jul 3, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Changes Made

Behavior

Benefits

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

Uh oh!

javiercn Jul 3, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jul 3, 2025

Choose a reason for hiding this comment

Uh oh!

lewing left a comment

Choose a reason for hiding this comment

Uh oh!

javiercn Jul 8, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jul 8, 2025

Choose a reason for hiding this comment

Uh oh!

javiercn left a comment

Choose a reason for hiding this comment

Uh oh!

Copilot AI commented Jul 8, 2025

Uh oh!

Copilot AI commented Jul 8, 2025

Uh oh!

Uh oh!

Uh oh!

Copilot AI commented Jul 3, 2025 •

edited

Loading