Hermes

Upload source maps for React Native Hermes applications.

Sentry's React Native SDK works out of the box with applications using Hermes engine. To see readable stack traces in the product source maps need to be uploaded to Sentry. This guide explains how to manually upload source maps from Hermes engine.

The easiest way to configure automatic source maps upload is to use the Sentry Wizard:

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npx @sentry/wizard@latest -i reactNative

To manually upload source maps, first, you need to generate the source maps and bundle. Then compile the Hermes bytecode bundle, and finally upload the source map to Sentry.

Start with adding Sentry React Native Metro Plugin to your metro.config.js:

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const { getDefaultConfig } = require("@react-native/metro-config");
const { withSentryConfig } = require("@sentry/react-native/metro");

const config = getDefaultConfig(__dirname);
module.exports = withSentryConfig(config);

Generate the React Native Packager (Metro) bundle and source maps:

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npx react-native bundle \
  --dev false \
  --minify false \
  --platform android \
  --entry-file index.js \
  --reset-cache \
  --bundle-output index.android.bundle \
  --sourcemap-output index.android.bundle.map

Compile Hermes bytecode bundle and source map:

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node_modules/react-native/sdks/hermesc/osx-bin/hermesc \
  -O -emit-binary \
  -output-source-map \
  -out=index.android.bundle.hbc \
  index.android.bundle
rm -f index.android.bundle
mv index.android.bundle.hbc index.android.bundle

Compose Hermes bytecode and (React Native Packager) Metro source maps:

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mv index.android.bundle.map index.android.bundle.packager.map
node \
  node_modules/react-native/scripts/compose-source-maps.js \
  index.android.bundle.packager.map \
  index.android.bundle.hbc.map \
  -o index.android.bundle.map
node \
  node_modules/@sentry/react-native/scripts/copy-debugid.js \
  index.android.bundle.packager.map index.android.bundle.map
rm -f index.android.bundle.packager.map

Make sure sentry-cli is configured for your project and set up your environment variables:

.env
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SENTRY_ORG=example-org
SENTRY_PROJECT=example-project
SENTRY_AUTH_TOKEN=sntrys_YOUR_TOKEN_HERE

Upload the bundle and source map to Sentry:

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node_modules/@sentry/cli/bin/sentry-cli sourcemaps upload \
  --debug-id-reference \
  --strip-prefix /path/to/project/root \
  index.android.bundle index.android.bundle.map

When uploaded, the bundle file will have a size of 0 bytes. This is expected with Hermes bytecode and won't affect the source maps resolution.

For more Hermes guides, see the Hermes Throubleshooting docs section.

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