feat(sdk,core): phase 3b — 8 gsap/label ops + setClassStyle (#1379)

This commit is contained in:
Vance Ingalls
2026-06-15 00:46:17 -07:00
committed by GitHub
parent 8b56e558c6
commit 6dcbb5530e
17 changed files with 1442 additions and 61 deletions
+137
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/**
* Hand-rolled flat-CSS rule editor.
*
* Handles only simple flat rules (`selector { declarations }`) — no nesting,
* no @-rules, no CSS comments. Sufficient for composition <style> blocks
* generated by hyperframes, which never contain those constructs.
*/
// ─── Types ────────────────────────────────────────────────────────────────────
interface CssRule {
selector: string;
body: string;
/** Byte offset of the first char of the selector. */
start: number;
/** Byte offset after the closing `}`. */
end: number;
}
// ─── Parsing ──────────────────────────────────────────────────────────────────
// fallow-ignore-next-line complexity
function parseCssRules(css: string): CssRule[] {
const rules: CssRule[] = [];
let i = 0;
const len = css.length;
while (i < len) {
const braceOpen = css.indexOf("{", i);
if (braceOpen === -1) break;
const selector = css.slice(i, braceOpen).trim();
if (!selector) {
i = braceOpen + 1;
continue;
}
// skip leading whitespace to get the true selector start
let selStart = i;
while (selStart < braceOpen && " \t\r\n".includes(css[selStart]!)) selStart++;
// find closing }, respecting quoted strings so `content: "}"` doesn't end the rule
let j = braceOpen + 1;
let quote: string | null = null;
while (j < len) {
const ch = css[j]!;
if (quote) {
if (ch === "\\" && j + 1 < len)
j++; // skip escaped char
else if (ch === quote) quote = null;
} else if (ch === '"' || ch === "'") {
quote = ch;
} else if (ch === "}") {
break;
}
j++;
}
rules.push({ selector, body: css.slice(braceOpen + 1, j), start: selStart, end: j + 1 });
i = j + 1;
}
return rules;
}
// fallow-ignore-next-line complexity
function parseDeclarations(body: string): Record<string, string> {
const decls: Record<string, string> = {};
let depth = 0;
let start = 0;
for (let i = 0; i <= body.length; i++) {
const ch = i < body.length ? body[i]! : ";"; // sentinel flush
if (ch === "(") depth++;
else if (ch === ")") depth--;
else if (ch === ";" && depth === 0) {
const part = body.slice(start, i);
const colon = part.indexOf(":");
if (colon !== -1) {
const prop = part.slice(0, colon).trim();
const value = part.slice(colon + 1).trim();
if (prop && value) decls[prop] = value;
}
start = i + 1;
}
}
return decls;
}
function serializeDeclarations(decls: Record<string, string>): string {
const entries = Object.entries(decls);
if (!entries.length) return "";
return " " + entries.map(([k, v]) => `${k}: ${v}`).join("; ") + "; ";
}
function normalizeSelector(sel: string): string {
return sel.trim().replace(/\s+/g, " ");
}
// ─── Public API ───────────────────────────────────────────────────────────────
/**
* Update or insert a CSS rule.
*
* Finds the first rule whose selector matches (after whitespace normalization)
* and merges the given declarations into it. A null value removes the property.
* If no matching rule exists, appends a new one.
*
* Returns the modified CSS string. Returns `css` unchanged when nothing changed.
*/
export function upsertCssRule(
css: string,
selector: string,
styles: Record<string, string | null>,
): string {
const normalized = normalizeSelector(selector);
const rules = parseCssRules(css);
const idx = rules.findIndex((r) => normalizeSelector(r.selector) === normalized);
if (idx !== -1) {
const rule = rules[idx]!;
const decls = parseDeclarations(rule.body);
for (const [prop, value] of Object.entries(styles)) {
if (value === null) {
delete decls[prop];
} else {
decls[prop] = value;
}
}
const newRuleText = `${rule.selector} {${serializeDeclarations(decls)}}`;
return css.slice(0, rule.start) + newRuleText + css.slice(rule.end);
}
// Append new rule — skip if all values are null (nothing to write).
const newDecls: Record<string, string> = {};
for (const [prop, value] of Object.entries(styles)) {
if (value !== null) newDecls[prop] = value;
}
if (!Object.keys(newDecls).length) return css;
const newRuleText = `${selector} {${serializeDeclarations(newDecls)}}`;
const sep = css.length > 0 && !css.endsWith("\n") ? "\n" : "";
return css + sep + newRuleText + "\n";
}