Function buildGroup

src/buildHTML.ts:259–291

(
    group: AnyParseNode | null | undefined,
    options: Options,
    baseOptions?: Options,
)

 * between parents and children.
 */
export const buildGroup = function(
    group: AnyParseNode | null | undefined,
    options: Options,
    baseOptions?: Options,
): HtmlDomNode {
    if (!group) {
        return makeSpan();
    }

    if (groupBuilders[group.type]) {
        // TODO(ts): groupBuilders is Record<string, HtmlBuilder<any>>;
        // a type-safe registry would need a mapped type keyed by NodeType.
        let groupNode: HtmlDomNode = groupBuilders[group.type](group, options);

        // If the size changed between the parent and the current group, account
        // for that size difference.
        if (baseOptions && options.size !== baseOptions.size) {
            groupNode = makeSpan(options.sizingClasses(baseOptions),
                [groupNode], options);

            const multiplier =
                options.sizeMultiplier / baseOptions.sizeMultiplier;

            groupNode.height *= multiplier;
            groupNode.depth *= multiplier;
        }

        return groupNode;
    } else {
        throw new ParseError(
            "Got group of unknown type: '" + group.type + "'");
    }
};

/**
 * Combine an array of HTML DOM nodes (e.g., the output of `buildExpression`)