feat: add playwright

src/index.ts

@@ -7,6 +7,7 @@ import { discover } from "./provider.js";
 import { descriptions, routingGuide } from "./routing.js";
 import { QuotaTracker } from "./quota.js";
 import { QuotaRpc } from "./quota-rpc.js";
+import { playwrightMcpCommand } from "./playwright.js";
 
 // Permission actions use wildcards, not filesystem globs.
 function matches(value: string, pattern: string) {
@@ -113,8 +114,11 @@ export default Plugin.define({
         const assignments = selected.mode === "gpt" ? gptAgents : selected.agents;
         let workers: (typeof workerNames)[number][] = [];
         const active = new Set<string>();
+        const playwrightCommand = await playwrightMcpCommand(context.location.directory);
 
         await context.mcp.transform((editor) => {
+            if (!editor.get("playwright"))
+                editor.set("playwright", { type: "local", command: playwrightCommand });
             hasCodegraph = editor.get("codegraph") !== undefined;
             if (hasCodegraph)
                 editor.update("codegraph", (server) => {

src/playwright.ts

@@ -0,0 +1,145 @@
+import { access, readFile, realpath } from "node:fs/promises";
+import { constants } from "node:fs";
+import { dirname, join, parse, resolve } from "node:path";
+import { z } from "zod";
+
+const dockerCommand = [
+    "docker",
+    "run",
+    "-i",
+    "--rm",
+    "--init",
+    "--pull=always",
+    "mcr.microsoft.com/playwright/mcp",
+];
+const directPackageManifest = z.object({
+    name: z.literal("@playwright/mcp"),
+    bin: z.string(),
+});
+const namedPackageManifest = z.object({
+    name: z.literal("@playwright/mcp"),
+    bin: z.object({ "playwright-mcp": z.string() }),
+});
+const playwrightPackageManifest = z.object({
+    name: z.literal("playwright"),
+    bin: z.object({ playwright: z.string() }),
+});
+const playwrightTestPackageManifest = z.object({
+    name: z.literal("@playwright/test"),
+    bin: z.object({ playwright: z.string() }),
+    dependencies: z.object({ playwright: z.string() }),
+});
+
+async function packageExecutable(packageRoot: string) {
+    try {
+        const input = JSON.parse(await readFile(join(packageRoot, "package.json"), "utf8"));
+        const direct = directPackageManifest.safeParse(input);
+        const bin = direct.success
+            ? direct.data.bin
+            : namedPackageManifest.parse(input).bin["playwright-mcp"];
+        const executable = resolve(packageRoot, bin);
+        await access(executable, constants.X_OK);
+        return executable;
+    } catch {
+        return;
+    }
+}
+
+async function ordinaryPackageExecutable(packageRoot: string) {
+    try {
+        const manifest = playwrightPackageManifest.parse(
+            JSON.parse(await readFile(join(packageRoot, "package.json"), "utf8")),
+        );
+        const executable = resolve(packageRoot, manifest.bin.playwright);
+        await access(executable, constants.X_OK);
+        return executable;
+    } catch {
+        return;
+    }
+}
+
+async function playwrightDependency(packageRoot: string) {
+    let current = await realpath(packageRoot);
+    const root = parse(current).root;
+    while (true) {
+        const executable = await ordinaryPackageExecutable(
+            join(current, "node_modules/playwright"),
+        );
+        if (executable) return executable;
+        if (current === root) return;
+        current = dirname(current);
+    }
+}
+
+async function testPackageExecutable(packageRoot: string) {
+    try {
+        const manifest = playwrightTestPackageManifest.parse(
+            JSON.parse(await readFile(join(packageRoot, "package.json"), "utf8")),
+        );
+        if (!(await playwrightDependency(packageRoot))) return;
+        const executable = resolve(packageRoot, manifest.bin.playwright);
+        await access(executable, constants.X_OK);
+        return executable;
+    } catch {
+        return;
+    }
+}
+
+async function verifiedPathExecutable(candidate: string, kind: "mcp" | "playwright") {
+    try {
+        await access(candidate, constants.X_OK);
+        const target = await realpath(candidate);
+        let directory = dirname(target);
+        const root = parse(directory).root;
+        while (true) {
+            const executable =
+                kind === "mcp"
+                    ? await packageExecutable(directory)
+                    : ((await ordinaryPackageExecutable(directory)) ??
+                      (await testPackageExecutable(directory)));
+            if (executable && (await realpath(executable)) === target) return candidate;
+            if (directory === root) return;
+            directory = dirname(directory);
+        }
+    } catch {
+        return;
+    }
+}
+
+export async function playwrightMcpCommand(
+    directory: string,
+    path = process.env.PATH ?? "",
+): Promise<string[]> {
+    let current = resolve(directory);
+    const root = parse(current).root;
+    while (true) {
+        const executable = await packageExecutable(join(current, "node_modules/@playwright/mcp"));
+        if (executable) return [executable];
+        if (current === root) break;
+        current = dirname(current);
+    }
+
+    for (const entry of path.split(process.platform === "win32" ? ";" : ":")) {
+        if (!entry) continue;
+        const executable = await verifiedPathExecutable(join(entry, "playwright-mcp"), "mcp");
+        if (executable) return [executable];
+    }
+
+    current = resolve(directory);
+    while (true) {
+        const playwright = await ordinaryPackageExecutable(
+            join(current, "node_modules/playwright"),
+        );
+        const test = await testPackageExecutable(join(current, "node_modules/@playwright/test"));
+        if (playwright || test) return ["npx", "-y", "@playwright/mcp@latest"];
+        if (current === root) break;
+        current = dirname(current);
+    }
+
+    for (const entry of path.split(process.platform === "win32" ? ";" : ":")) {
+        if (!entry) continue;
+        const executable = await verifiedPathExecutable(join(entry, "playwright"), "playwright");
+        if (executable) return ["npx", "-y", "@playwright/mcp@latest"];
+    }
+    return [...dockerCommand];
+}