chore: update comment

Author: bluwy

packages/e2e-tests/vite-ssr-esm/vite.config.js

@@ -14,8 +14,18 @@ export default defineConfig(({ command, mode }) => {
 				}
 			}
 		},
-		// TODO: investigate the condition issue. it's the same thing dominik and ben found.
-		// idk why it's only happening after https://github.com/vitejs/vite/pull/18395
+		// Because `esm-env` is used by Svelte to determine running in dev mode, and that package
+		// uses `development` condition to determine so in dev. And on the other hand, Vite uses
+		// `process.env.NODE_ENV` to determine dev mode, which v-p-s passes to `compilerOptions.dev`,
+		// there's a potential mismatch of dev condition that Svelte doesn't expect, causing a runtime
+		// error at https://github.com/sveltejs/svelte/blob/53af138d588f77bb8f4f10f9ad15fd4f798b50ef/packages/svelte/src/internal/server/dev.js#L70
+		// TODO: Figure out if either:
+		// 1. Svelte should work resiliently with mismatch dev/prod modes.
+		// 2. We hardcode `ssr.noExternal: ['esm-env']` in v-p-s directly, however we're not resolving the root cause.
+		// 3. We crawl recursively for `esm-env` to resolve no2, but still kinda hacky.
+		// 4. Encourage users to set `NODE_OPTIONS="--conditions development"` when running vite dev.
+		// 5. Vite should revert it's external resolve logic, however we're also not resolving the root cause.
+		// ... or something else
 		ssr: {
 			noExternal: ['esm-env']
 		},