fix(sveltekit): Avoid creating the Sentry Vite plugin in dev mode (#8065)

Don't call the Vite plugin factory function in dev mode to keep the bundler plugin from leaking its telemetry tags to users' Sentry instance. We don't want to upload source maps in dev mode anyway.

Author: Lms24

packages/sveltekit/src/vite/sentryVitePlugins.ts

@@ -78,7 +78,7 @@ export async function sentrySvelteKit(options: SentrySvelteKitPluginOptions = {}
     );
   }
 
-  if (mergedOptions.autoUploadSourceMaps) {
+  if (mergedOptions.autoUploadSourceMaps && process.env.NODE_ENV !== 'development') {
     const pluginOptions = {
       ...mergedOptions.sourceMapsUploadOptions,
       debug: mergedOptions.debug, // override the plugin's debug flag with the one from the top-level options

packages/sveltekit/test/vite/sentrySvelteKitPlugins.test.ts

@@ -38,6 +38,19 @@ describe('sentryVite()', () => {
     expect(plugins).toHaveLength(1);
   });
 
+  it("doesn't return the custom sentry source maps plugin if `NODE_ENV` is development", async () => {
+    const previousEnv = process.env.NODE_ENV;
+
+    process.env.NODE_ENV = 'development';
+    const plugins = await sentrySvelteKit({ autoUploadSourceMaps: true, autoInstrument: true });
+    const instrumentPlugin = plugins[0];
+
+    expect(plugins).toHaveLength(1);
+    expect(instrumentPlugin.name).toEqual('sentry-auto-instrumentation');
+
+    process.env.NODE_ENV = previousEnv;
+  });
+
   it("doesn't return the auto instrument plugin if autoInstrument is `false`", async () => {
     const plugins = await sentrySvelteKit({ autoInstrument: false });
     expect(plugins).toHaveLength(1);