Lanes verdict at the edge: lanes.json no longer invalidates every regen step

[thejackshelton]

Why

packages/dragon/src/project.ts imported profiles/native-lanes.ts, which profile:rows generates from packages/parity/out/lanes.json. That put the lanes verdict in the regen key of 21 steps. Whenever lanes-host rewrote lanes.json at the end of pass 1, for example when vectors changed and device lanes went stale, profile-rows rewrote native-lanes.ts in pass 2 and every compiling step reran. That pass took about 15 minutes and usually changed 0 files, and the same happened again after every device run. The PM approved this design (REGEN-SPEED decision 1).

What changed

• Compiler. project.ts no longer imports native-lanes.ts. The verdict is a new option, InternalOptions.nativeLanes. Without it, a checked native output is analysis-only with the reason "no committed lanes verdict was given to this compilation". It is never ready, so a missing verdict never reads as passing. nativeOutputState takes null for that case. The native digest does not include the verdict, before or after.
• Public API, unchanged. createProject moves to the new create-project.ts, which passes the committed NATIVE_LANES at the edge.
  • index.ts now exports api.ts (the shared public API, moved verbatim from index.ts) plus createProject. Its export list is the same.
  • internal.ts exports api.ts, so the internal entry, and every step that runs under --conditions=dragon-internal, no longer reaches the verdict.
• Regen keying (scripts/regen-inputs.ts, scripts/regen.ts). Before, a workspace package was keyed on every export target under every condition, so 'dragon' always pulled in index.ts. Now:
  • commandOf records each node invocation's --conditions= flags. It refuses the -C and --conditions <x> spellings, which it would otherwise misread.
  • importClosure resolves a workspace package to the entries Node picks under each process's conditions, using a new exportTargetsUnder.
  • Called without conditions it behaves as before.
  • The trace check still fails any run whose process loads an entry the key left out, so the narrower key cannot miss an input. lanes-host's child processes, for instance, are checked the same way.
• Result: native-lanes.ts is now an input of north-star only, which uses the public createProject. Before, it was an input of 21 steps.

Tests (each fails without the change it covers)

• outputs-ready.test.ts, new test:
  • no verdict gives analysis-only, saying so;
  • a passing verdict gives ready on both targets, so the absent verdict is not read as a pass;
  • the public createProject gives exactly the committed-verdict outputs;
  • the digest does not depend on the verdict.
• regen.test.ts, new test: closure under conditions. Internal-only, public-only, two processes, no conditions (unchanged), and Node's first-matching-key rule in exportTargetsUnder. The commandOf test now also checks the recorded conditions and the refused -C spelling.
• Retargeted: regen.test.ts "changes the key for an import...". Its step now runs with --conditions=dragon-internal, so the internal-only file it edits is still an input, and the intent (an import changes the key) is kept. It now also checks that without the condition that file is no input.
• Retargeted imports: dist.test.ts, media-sweep.test.ts and north-star-tree.test.ts now import createProject from dragon/src/index.ts. Their 'dragon' import resolves to the internal entry, which no longer exports it. Nothing else changes.

What passed

• pnpm typecheck: pass.
• vitest run: regen.test.ts (32 passed, 2 skipped opt-in), outputs-ready, ua, s5, media-wiring, android-target, grid and compile tests (157 passed).
• pnpm regen on the branch (job regen-speed-lanes-edge-regen): 19 steps ran. Fixed point after 1 pass, 0 files changed, git status clean. Every output is byte-identical, and the trace guard accepted every narrowed key.

Note

project.ts is also edited by many in-flight PRs. This one touches only its import lines, the InternalOptions and Resolved types, one line of the compile loop, nativeOutputState, and the removed createProject.

No tolerance or check is loosened.

🤖 Generated with Claude Code

[thejackshelton]

Landing stopped at step merge (pnpm land)

merge-train: merging native-lanes-at-edge onto 918aa25b016852bd6a44f68748c1ed9d5dbca5b8 failed; conflicts in packages/parity/test/regen.test.ts, scripts/regen.ts

Fix the cause, then hand #153 back to the landing queue with the new clean head.