Function css

packages/@react-spectrum/s2/style/style-macro.ts:1103–1131

(this: MacroContext | void, content: string, layer = '_.a')

 * @returns The generated class name that applies the styles.
 */
export function css(this: MacroContext | void, content: string, layer = '_.a'): string {
  // Check if `this` is undefined, which means style was not called as a macro but as a normal function.
  // We also check if this is globalThis, which happens in non-strict mode bundles.
  // Also allow style to be called as a normal function in tests.
  // @ts-ignore

  if ((this == null || this === globalThis) && process.env.NODE_ENV !== 'test') {
    throw new Error('The css macro must be imported with {type: "macro"}.');
  }
  let className = generateArbitraryValueSelector(content, true);
  content = `@layer ${layer} {
  .${className} {
  ${content}
  }
}`;

  // Ensure layer is always declared after the _ layer used by style macro.
  if (!layer.startsWith('_.')) {
    content = `@layer _, ${layer};\n` + content;
  }

  if (this && typeof this.addAsset === 'function') {
    this.addAsset({
      type: 'css',
      content
    });
  }
  return className;
}

export function keyframes(this: MacroContext | void, css: string): string {
  // Check if `this` is undefined, which means style was not called as a macro but as a normal function.