split createSubResolver

Author: kurkle

src/helpers/helpers.config.js

@@ -63,6 +63,7 @@ export function _attachContext(proxy, context, subProxy) {
 			if (isPublicOptionValue(prop, value)) {
 				if (isFunction(value) && isScriptable(prop)) {
 					if (stack.has(prop)) {
+						// @ts-ignore
 						throw new Error('Recursion detected: ' + [...stack].join('->') + '->' + prop);
 					}
 					stack.add(prop);
@@ -126,21 +127,13 @@ export function _descriptors(proxy) {
 }
 
 function createSubResolver(parentScopes, prop, value) {
-	const scopes = new Set([value]);
-	const fallback = _resolve('_fallback', parentScopes.map(scope => scope[prop] || scope));
-	const keys = [prop];
-	if (defined(fallback)) {
-		const resolved = isFunction(fallback) ? fallback(prop, value) : fallback;
-		keys.unshift(...(isArray(resolved) ? resolved : [resolved]));
-	}
+	const set = new Set([value]);
+	const keys = _resolveSubKeys(parentScopes, prop, value);
 	for (const key of keys) {
-		if (!key) {
-			continue;
-		}
 		for (const item of parentScopes) {
 			const scope = resolveObjectKey(item, key);
 			if (scope) {
-				scopes.add(scope);
+				set.add(scope);
 			} else if (key !== prop && scope === false) {
 				// If any of the fallback scopes is explicitly false, return false
 				// For example, options.hover falls back to options.interaction, when
@@ -149,8 +142,18 @@ function createSubResolver(parentScopes, prop, value) {
 			}
 		}
 	}
-	parentScopes.forEach(scopes.add, scopes);
-	return _createResolver([...scopes]);
+	parentScopes.forEach(set.add, set);
+	return _createResolver([...set]);
+}
+
+function _resolveSubKeys(parentScopes, prop, value) {
+	const fallback = _resolve('_fallback', parentScopes.map(scope => scope[prop] || scope));
+	const keys = [prop];
+	if (defined(fallback)) {
+		const resolved = isFunction(fallback) ? fallback(prop, value) : fallback;
+		keys.unshift(...(isArray(resolved) ? resolved : [resolved]));
+	}
+	return keys.filter(v => v);
 }
 
 function _resolveWithPrefixes(prop, prefixes, scopes) {