wehub-resource-sync
11 lines
547 B
TypeScript
11 lines
547 B
TypeScript
// Shared e2e helpers. One relative-luminance implementation for every spec
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// that asserts on computed colors — fix parsing quirks here, once.
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/** Approximate relative luminance (0..1) of a computed `rgb()`/`rgba()` color. */
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export function relativeLuminance(color: string): number {
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const m = color.match(/rgba?\(\s*([\d.]+)[,\s]+([\d.]+)[,\s]+([\d.]+)/)
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if (!m) throw new Error(`Unexpected computed color: ${color}`)
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const [r, g, b] = [Number(m[1]), Number(m[2]), Number(m[3])]
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return (0.2126 * r + 0.7152 * g + 0.0722 * b) / 255
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}
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