[Vite plugin] Incorrect sourcemap paths

[TmLev]

Describe what happened

datadogVitePlugin produces incorrect paths for minified assets, e.g. /assets/home/runner/<REDACTED>/assets/DataGrid-DrStp6xt.js (taken from "Uploaded Debug Symbols" hereinafter).

Steps to reproduce the issue:

I took the following Vite config:

export default defineConfig({
  plugins: [
    datadogVitePlugin({
      errorTracking: {
        sourcemaps: {
          minifiedPathPrefix: "/assets/",
        },
      },
    }),

    // Other plugins omitted for brevity.
  ],

  build: {
    sourcemap: true,
    outDir: "./dist",
  },
});

And run vite build --mode production.

Expected behaviour:

Sourcemaps should be associated with paths starting with minifiedPathPrefix which is /assets/ in my case.

It even works when I use the following CLI command:

        `DATADOG_SITE=${VITE_DATADOG_SITE} pnpm exec datadog-ci sourcemaps upload ./dist/assets ` +
          `--service ${VITE_DATADOG_SERVICE} ` +
          `--release-version ${currentVersion} ` +
          `--minified-path-prefix /assets`

Final path: /assets/DataGrid-HKXszdMm.js

Actual behaviour:

Sourcemaps get weird filesystem paths instead, e.g.

/assets/home/runner/<REDACTED>/assets/DataGrid-DrStp6xt.js

Additional context

I'm using Github Actions to deploy my Vite+React project (so the /home/runner part of the path comes from that).

OS version: ubuntu-latest
Node version: 20
Vite version: 5.4.14
@datadog/vite-plugin version: 2.6.1

An explanation of what might cause the bug: incorrect handling of ourDir and filepaths.
An explanation of how it can be fixed: trace the way final minified path gets assembled.

Examples of other minifiedPathPrefix & outDir combinations

I've tried using FQDN for the minifiedPathPrefix:

export default defineConfig({
  plugins: [
    datadogVitePlugin({
      errorTracking: {
        sourcemaps: {
          minifiedPathPrefix: "https://full-domain.com/assets/",
        },
      },
    }),
  ],

  build: {
    sourcemap: true,
    outDir: "./dist",
  },
});


// Sourcemap path: /full-domain.com/assets/home/runner/<REDACTED>/dist/assets/DataGrid-C_85C0L2.js

Removing ./ from the ./dist leads to /dist being completely dropped from the path:

export default defineConfig({
  plugins: [
    datadogVitePlugin({
      errorTracking: {
        sourcemaps: {
          minifiedPathPrefix: "/assets/", // <--- Removed full domain.
        },
      },
    }),
  ],

  build: {
    sourcemap: true,
    outDir: "dist", // <--- THIS IS THE DEFAULT.
  },
});


// Sourcemap path: /assets/home/runner/<REDACTED>/assets/DataGrid-DrStp6xt.js
// Completely missing the `/dist` part of the path.

[TmLev]

With the following config:

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [
    datadogVitePlugin({
      errorTracking: {
        sourcemaps: {
          minifiedPathPrefix: "https://full-domain.com/assets/",
        },
      },
    }),
  ],

  build: {
    sourcemap: true,
    outDir: "dist",
  },
});

The decomposePath function has this:

[decomposePath] sourcemapFilePath /home/runner/<REDACTED>/dist/assets/unauthorized-BBB5hoyb.js.map
[decomposePath] bundlerOutDir dist
[decomposePath] options.minifiedPathPrefix https://full-domain.com/assets/
[decomposePath] relativePath /home/runner/<REDACTED>//assets/unauthorized-BBB5hoyb.js   <--- Double slash.
[decomposePath] minifiedUrl https:/full-domain.com/assets/home/runner/<REDACTED>/assets/unauthorized-BBB5hoyb.js

Notice the strange relativePath and a single slash in the https:/full-domain.com and filesystem URL in the minifiedUrl.

I think this line

build-plugins/packages/plugins/error-tracking/src/sourcemaps/files.ts

Line 23 in b47402d

const relativePath = minifiedFilePath.replace(context.bundler.outDir, '');

is not correct in cases where outDir is not an absolute path.

[TmLev]

The following diff works for my use case (although I'm not sure how correct it is):

diff --git a/packages/plugins/bundler-report/src/index.ts b/packages/plugins/bundler-report/src/index.ts
index 9fcc829..38f3ba1 100644
--- a/packages/plugins/bundler-report/src/index.ts
+++ b/packages/plugins/bundler-report/src/index.ts
@@ -144,9 +144,11 @@ export const getBundlerReportPlugins: GetInternalPlugins = (arg: GetPluginsArg)
         vite: {
             ...(rollupPlugin() as PluginOptions['vite']),
             config(config) {
-                if (config.build?.outDir) {
-                    context.bundler.outDir = config.build.outDir;
-                }
+                // Resolve outDir relative to Vite's root (or process.cwd() if no root)
+                const viteRoot = config.root || process.cwd();
+                // Use Vite's default outDir of "dist" if not specified
+                const outDir = config.build?.outDir || 'dist';
+                context.bundler.outDir = getAbsolutePath(viteRoot, outDir);
 
                 if (config.root) {
                     context.cwd = config.root;
diff --git a/packages/plugins/error-tracking/src/sourcemaps/files.ts b/packages/plugins/error-tracking/src/sourcemaps/files.ts
index 8df9810..52bf0d9 100644
--- a/packages/plugins/error-tracking/src/sourcemaps/files.ts
+++ b/packages/plugins/error-tracking/src/sourcemaps/files.ts
@@ -20,10 +20,12 @@ const decomposePath = (
     }
 
     const minifiedFilePath = sourcemapFilePath.replace(/\.map$/, '');
-    const relativePath = minifiedFilePath.replace(context.bundler.outDir, '');
-    const minifiedUrl = options.minifiedPathPrefix
-        ? path.join(options.minifiedPathPrefix, relativePath)
-        : relativePath;
+    const relativePath = path.relative(context.bundler.outDir, minifiedFilePath);
+    const minifiedUrl = path.join(options.minifiedPathPrefix, relativePath).replace(/\\/g, '/');
 
     return {
         minifiedFilePath,

Note that options.minifiedPathPrefix is always present (since it's required by the type system and validation) so the whole options.minifiedPathPrefix ? check is redundant.

[yoannmoinet]

Thank you very much for the detailed report, it's really appreciated.
Most definitely a bug.

I'll have a look asap.

[TmLev]

Thanks! Let me know if you need anything else from me

[yoannmoinet]

Took a stab at it in #182

If you have a sec @TmLev can you confirm this would work for your use case?

[yoannmoinet]

This has been fixed in https://github.com/DataDog/build-plugins/releases/tag/v2.6.2

[TmLev]

Not sure #182 fixed the issue entirely – using "dist" as outputDir produces incorrect paths:

 - /home/runner/<REDACTED>/./assets/route-CaFva2_5.js

Compared to using "./dist" which should be exactly the same:

 - /home/runner/<REDACTED>/dist/assets/route-CaFva2_5.js

[yoannmoinet]

Oh no.
I'll investigate this week.
Sorry about that, I really thought I had covered most of it.