make it harder for the optimizer to incorrectly export DEV twice

[xunilrj]

Summary

Try to fix #1660. I think skypack is complaining because dev.cjs after being optimized has

exports.DEV = void 0;
exports.DEV = {
  hooks: DevHooks,
  writeSignal,
  registerGraph
};

This change make it harder for the optimizer to export DEV twice.

const DEV = "_SOLID_DEV_"
  ? ({ hooks: DevHooks, writeSignal, registerGraph } as {
      readonly hooks: typeof DevHooks;
      readonly writeSignal: typeof writeSignal;
      readonly registerGraph: typeof registerGraph;
    })
  : undefined;
export { DEV };

How did you test this change?

I can´t test if this will fix skypack build.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 705820c

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[thetarnav]

Why not use a ternary? ("SOLID_DEV" ? { ... } : undefined)
The DEV object is used in libraries as a development mode check, so it being falsy needs to cause that code path to be tree-shaken.
Also the same DEV object is exported from the /store module.

[xunilrj]

Good idea. The optimizer seems happy with that.

const DEV = {
  hooks: DevHooks,
  writeSignal,
  registerGraph
} ;
exports.DEV = DEV;

[coveralls]

Pull Request Test Coverage Report for Build 4581620121

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 3 of 5 (60.0%) changed or added relevant lines in 1 file are covered.
• 3 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.1%) to 93.963%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/solid/src/index.ts	3	5	60.0%

Files with Coverage Reduction	New Missed Lines	%
packages/solid/src/index.ts	3	93.81%

Totals
Change from base Build 4561177901:	-0.1%
Covered Lines:	4080
Relevant Lines:	4277

---

💛 - Coveralls