Add deterministic-tests (#190)

Reviewed-on: https://home.schmelczer.dev/git/git/andras/vault-link/pulls/190
Co-authored-by: Andras Schmelczer <andras@schmelczer.dev>
Co-committed-by: Andras Schmelczer <andras@schmelczer.dev>

frontend/deterministic-tests/src/parse-args.ts

@@ -0,0 +1,43 @@
+import * as os from "node:os";
+import { Command, InvalidArgumentError } from "commander";
+
+export interface CliArgs {
+    filter: string | undefined;
+    concurrency: number;
+}
+
+function parsePositiveInt(value: string): number {
+    const n = parseInt(value, 10);
+    if (isNaN(n) || n <= 0) {
+        throw new InvalidArgumentError("must be a positive integer");
+    }
+    return n;
+}
+
+export function parseArgs(argv: string[]): CliArgs {
+    const program = new Command();
+
+    program
+        .name("deterministic-tests")
+        .description("Scripted multi-client sync tests against a real server")
+        .option(
+            "-f, --filter <substring>",
+            "Run only tests whose name contains this substring"
+        )
+        .option(
+            "-j, --concurrency <number>",
+            "Number of tests to run in parallel",
+            parsePositiveInt,
+            os.cpus().length
+        );
+
+    program.parse(argv);
+
+    /* eslint-disable @typescript-eslint/no-unsafe-type-assertion */
+    const opts = program.opts();
+    const filter = opts.filter as string | undefined;
+    const concurrency = opts.concurrency as number;
+    /* eslint-enable @typescript-eslint/no-unsafe-type-assertion */
+
+    return { filter, concurrency };
+}