Initial commit

skills/browser-tools/scripts/evaluate.js

@@ -0,0 +1,114 @@
+#!/usr/bin/env node
+
+import { readFile } from "node:fs/promises";
+import puppeteer from "puppeteer-core";
+
+import {
+    DEFAULT_PORT,
+    createLogger,
+    fail,
+    getActivePage,
+    parseArgs,
+    printJSON,
+    resolveBrowserConnection,
+    normalizeNumber,
+} from "./config.js";
+
+const args = parseArgs(process.argv.slice(2), {
+    boolean: ["json", "quiet"],
+    string: ["file", "ws", "host"],
+    number: ["port", "timeout", "truncate"],
+    alias: {
+        j: "json",
+        q: "quiet",
+    },
+    defaults: {
+        port: DEFAULT_PORT,
+        timeout: 30000,
+        truncate: 8000,
+    },
+});
+
+const jsonOutput = Boolean(args.json);
+const logger = createLogger({ quiet: Boolean(args.quiet), json: jsonOutput });
+
+const expression = await resolveExpression(args);
+
+if (!expression) {
+    fail("No JavaScript provided. Pass an expression or use --file/STDIN.", { json: jsonOutput });
+}
+
+const timeout = normalizeNumber(args.timeout, 30000);
+const port = normalizeNumber(args.port, DEFAULT_PORT);
+
+const connectionOptions = resolveBrowserConnection({ port, host: args.host, ws: args.ws });
+
+let browser;
+try {
+    browser = await puppeteer.connect({
+        ...connectionOptions,
+        timeout,
+    });
+} catch (error) {
+    fail(`Failed to connect to browser: ${error.message}`, { json: jsonOutput });
+}
+
+try {
+    const page = await getActivePage(browser, { index: -1 });
+    if (!page) {
+        fail("No active page found. Navigate to a page first.", { json: jsonOutput });
+    }
+
+    const result = await page.evaluate(async (code) => {
+        const AsyncFunction = Object.getPrototypeOf(async function () {}).constructor;
+        const fn = new AsyncFunction(`return (${code})`);
+        return await fn();
+    }, expression);
+
+    const truncated = truncateResult(result, normalizeNumber(args.truncate, 8000));
+
+    if (jsonOutput) {
+        printJSON({ ok: true, result });
+    } else {
+        process.stdout.write(`${truncated}\n`);
+        logger.info(truncated);
+    }
+} catch (error) {
+    fail(`Evaluation failed: ${error.message}`, { json: jsonOutput });
+} finally {
+    if (browser) await browser.disconnect();
+}
+
+async function resolveExpression(parsed) {
+    if (parsed.file) {
+        const content = await readFile(parsed.file, "utf8");
+        return content.trim();
+    }
+
+    if (parsed._.length > 0) {
+        return parsed._.join(" ");
+    }
+
+    if (!process.stdin.isTTY) {
+        const chunks = [];
+        for await (const chunk of process.stdin) {
+            chunks.push(chunk);
+        }
+        return Buffer.concat(chunks.map((chunk) => Buffer.from(chunk))).toString("utf8").trim();
+    }
+
+    return null;
+}
+
+function truncateResult(value, maxLength) {
+    if (value === undefined) return "undefined";
+    if (value === null) return "null";
+
+    if (typeof value === "string") {
+        return value.length > maxLength ? `${value.slice(0, maxLength)}…` : value;
+    }
+
+    const serialized = JSON.stringify(value, null, 2);
+    if (!serialized) return String(value);
+    return serialized.length > maxLength ? `${serialized.slice(0, maxLength)}…` : serialized;
+}