Retry Prism on occupied ports

plugins/importer-openapi/tests/roundtrip.mjs

@@ -55,22 +55,41 @@ function listIds(output) {
 }
 
 async function startPrism(spec, port) {
+  for (let attempt = 0; attempt < 20; attempt++, port++) {
     const prism = spawn(
       "npx",
-    ["-y", "@stoplight/prism-cli", "mock", "--errors", "-p", String(port), "-h", "127.0.0.1", spec],
+      [
+        "-y",
+        "@stoplight/prism-cli",
+        "mock",
+        "--errors",
+        "-p",
+        String(port),
+        "-h",
+        "127.0.0.1",
+        spec,
+      ],
       { stdio: ["ignore", "pipe", "pipe"] },
     );
     let log = "";
     prism.stdout.on("data", (d) => (log += d));
     prism.stderr.on("data", (d) => (log += d));
     const deadline = Date.now() + 30_000;
+    let failed = false;
     while (Date.now() < deadline) {
-    if (log.includes("Prism is listening")) return { prism, getLog: () => log };
+      if (log.includes("Prism is listening")) return { prism, port, getLog: () => log };
-    if (prism.exitCode != null) throw new Error(`Prism exited:\n${log}`);
+      if (log.includes("EADDRINUSE") || prism.exitCode != null) {
+        failed = true;
+        break;
+      }
       await new Promise((r) => setTimeout(r, 200));
     }
     prism.kill();
-  throw new Error(`Prism did not start in time:\n${log}`);
+    if (failed && log.includes("EADDRINUSE")) continue;
+    if (!failed) throw new Error(`Prism did not start in time:\n${log}`);
+    throw new Error(`Prism exited:\n${log}`);
+  }
+  throw new Error("No free port found for Prism");
 }
 
 function pointVariablesAtPrism(variables, prismUrl) {
@@ -166,7 +185,10 @@ for (const spec of specs) {
       JSON.stringify({ id: workspaceId, settingFollowRedirects: false }),
     ]);
 
-    const prismUrl = `http://127.0.0.1:${port}`;
+    const { prism, port: boundPort, getLog } = await startPrism(spec, port);
+    port = boundPort + 1;
+    try {
+      const prismUrl = `http://127.0.0.1:${boundPort}`;
       const environmentIds = listIds(yaak(dataDir, ["environment", "list", workspaceId]));
       let activeEnvironment = null;
       for (const id of environmentIds) {
@@ -206,9 +228,6 @@ for (const spec of specs) {
         }
       }
 
-    const { prism, getLog } = await startPrism(spec, port);
-    port++;
-    try {
       const sendArgs = ["send", workspaceId];
       if (activeEnvironment != null) sendArgs.push("-e", activeEnvironment);
       try {