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// The baseline for relative requests — attributes alone make an unstyled h1 look |
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// size-less, so "larger" snaps below the theme default. |
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const ALLOWLIST = [ |
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'fontSize', |
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'lineHeight', |
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'fontWeight', |
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'fontFamily', |
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'fontStyle', |
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'letterSpacing', |
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'textTransform', |
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'textDecoration', |
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'color', |
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'backgroundColor', |
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'borderRadius', |
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'borderWidth', |
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'borderStyle', |
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'borderColor', |
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'boxShadow', |
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'padding', |
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'margin', |
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'minHeight', |
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]; |
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|
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// Every block computes a min-height; only a set one is a size to step from. |
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const isEmptyValue = (value, prop) => |
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!value || |
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value === 'normal' || |
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value === 'none' || |
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value === 'auto' || |
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(prop === 'minHeight' && value === '0px'); |
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|
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export const readComputedStyles = (el) => { |
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if (!el?.ownerDocument?.defaultView) return null; |
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const cs = el.ownerDocument.defaultView.getComputedStyle(el); |
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const out = {}; |
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for (const prop of ALLOWLIST) { |
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const value = cs[prop]; |
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if (!isEmptyValue(value, prop)) out[prop] = value; |
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} |
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return Object.keys(out).length ? out : null; |
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}; |
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|
