Function extractFencedTypeScript

src/compiled/cognition/validate.js:499–528

* Extract the largest TypeScript-tagged code fence from a model's response. * Models commonly wrap their output in ```typescript ... ``` (sometimes ```ts * or ```tsx). When that's present, the prose around the fence is never valid * TS — keeping it in the validator would just produce noise. If no

(value)

 * forgot the language tag.
 */
function extractFencedTypeScript(value) {
    // Match ```<lang?>\n ... \n``` blocks. Lang is optional and case-insensitive.
    // We use a non-greedy `[\s\S]*?` so consecutive fences don't merge.
    const fenceRe = /```([a-zA-Z]*)\s*\n([\s\S]*?)\n```/g;
    const tsFences = [];
    const untaggedFences = [];
    let m;
    while ((m = fenceRe.exec(value)) !== null) {
        const lang = (m[1] || "").toLowerCase();
        const body = m[2];
        if (lang === "typescript" || lang === "ts" || lang === "tsx") {
            tsFences.push(body);
        }
        else if (lang === "") {
            untaggedFences.push(body);
        }
    }
    // Prefer typescript-tagged fences. Fall back to the largest untagged one
    // since some models drop the language tag. If neither, return the whole
    // input — the legacy behaviour.
    const pool = tsFences.length > 0 ? tsFences : untaggedFences;
    if (pool.length === 0)
        return value;
    let best = pool[0];
    for (let i = 1; i < pool.length; i++) {
        if (pool[i].length > best.length)
            best = pool[i];
    }
    return best;
}
/**
 * Delegate to a user-supplied extension_point. The extension may return
 * either a `ValidationReport` shape (`{ ok, issues }`) for rich feedback,