Description

This fixes a bug where using compoundVariants with a boolean variant doesn't recognize undefined as equivalent to false.

bug reproduction code:

const h1 = tv({
  base: "",
  variants: {
    isBig: {
      true: "text-5xl",
      false: "text-2xl",
    },
  },
  compoundVariants: [
    {
      isBig: false,
      class: "text-red-500",
    },
  ],
});

h1({ isBig: undefined }) // should get "text-2xl text-red-500", but it's getting "text-2xl"

The bug is reported in #209

Additional context

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Follow the Style Guide.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).