Import condition resolution wrong per Vite environment (`react-server`, `edge-light`, `browser`)

[james-elicx]

This issue was created by an agent analysing CI failures from the Next.js Deploy Suite (vinext main vs Next.js v16.2.6, 2026-05-20).

Problem

Vite import conditions (react-server, edge-light, browser) are not being set correctly per environment. Package exports conditions should resolve differently depending on which Vite environment is doing the importing:

• RSC environment: Should resolve react-server condition
• Edge runtime: Should resolve edge-light condition
• Client/browser: Should resolve browser condition
• SSR/Node: Should resolve node condition

Tests show that conditions like react-server resolve to null when they should have a value, and edge-light resolves as node instead.

Estimated Impact

~11 test failures.

Affected Test Suites

• test/e2e/import-conditions/import-conditions.test.ts (11 failures)

Recommendation

1. Reproduce first in vinext's own test suite. Add a test with a package that has different exports conditions (e.g., react-server, edge-light, browser, node) and verify the correct export is resolved in each environment. Confirm the wrong condition is being used.

2. Study how conditions are configured per environment. Check resolve.conditions in the Vite config for each environment (RSC, SSR, client). The RSC environment needs ["react-server", ...], edge environments need ["edge-light", "worker", ...], and client needs ["browser", ...].

3. Fix the Vite plugin's environment configuration. In the vinext Vite plugin (index.ts), ensure each environment's resolve.conditions array includes the correct conditions for that context.

[james-elicx]

Still observed in the Next.js Deploy Suite nightly run on 2026-05-22 (vinext main vs Next.js v16.2.6): 9 failures across 1 test suites.

Affected suites this run

• test/e2e/import-conditions/import-conditions.test.ts (9 failures)

[james-elicx]

Investigated. PR #1396 (fix(build): set correct resolve.conditions per Vite environment) addresses this end-to-end and is currently:

• State: open, mergeable, mergeStateStatus CLEAN
• All CI checks passing (Vitest unit/integration, all E2E, CodeQL, deploys)
• Approved by ask-bonk with only non-blocking observations

The PR explicitly sets resolve.conditions per Vite environment to match Next.js webpack conditionNames:

• RSC env → react-server + server defaults (+ edge-light/workerd/worker on Cloudflare/Nitro)
• SSR env → server defaults (+ edge conditions on Cloudflare/Nitro)
• Client env → module / browser / development|production
• Pages Router SSR/client envs get matching node / browser conditions

It also adds tests/import-conditions.test.ts (7 tests, all fail on main, pass on the branch).

It looks ready to merge — no further code work is needed on a separate PR. Three non-blocking refinements were noted in the review that could be follow-ups after merge:

1. Add a comment on the Pages Router + Cloudflare branch explaining why no SSR env is emitted (Cloudflare plugin owns that env).
2. Drop the node condition from workerd SSR conditions to more precisely mirror Next.js' separate Node vs Edge conditionNames arrays.
3. Add a test for the Pages Router + Cloudflare client conditions branch.

Leaving open for a maintainer to merge #1396.