fix(dev): better error message when remix-serve is not found

.changeset/rude-geese-remain.md

@@ -0,0 +1,5 @@
+---
+"@remix-run/dev": patch
+---
+
+better error message when `remix-serve` is not found

packages/remix-dev/cli/commands.ts

@@ -25,7 +25,6 @@ import { TaskError } from "../codemod/utils/task";
 import { transpile as convertFileToJS } from "./useJavascript";
 import { warnOnce } from "../warnOnce";
 import type { Options } from "../compiler/options";
-import { getAppDependencies } from "../dependencies";
 
 export async function create({
   appTemplate,
@@ -502,7 +501,7 @@ let resolveDevOrigin = async (
 };
 
 type DevServeFlags = DevOrigin & {
-  command: string;
+  command?: string;
   restart: boolean;
 };
 let resolveDevServe = async (
@@ -518,25 +517,6 @@ let resolveDevServe = async (
   let command =
     flags.command ??
     (dev === true ? undefined : dev.command)
-  if (!command) {
-    command = `remix-serve ${path.relative(
-      process.cwd(),
-      config.serverBuildPath
-    )}`;
-
-    let usingRemixAppServer =
-      getAppDependencies(config, true)["@remix-run/serve"] !== undefined;
-    if (!usingRemixAppServer) {
-      console.error(
-        [
-          `Remix dev server command defaulted to '${command}', but @remix-run/serve is not installed.`,
-          "If you are using another server, specify how to run it with `-c` or `--command` flag.",
-          "For example, `remix dev -c 'node ./server.js'`",
-        ].join("\n")
-      );
-      process.exit(1);
-    }
-  }
 
   let restart =
     flags.restart ?? (dev === true ? undefined : dev.restart) ?? true;

packages/remix-dev/devServer_unstable/index.ts

@@ -18,6 +18,7 @@ import { detectPackageManager } from "../cli/detectPackageManager";
 import * as HDR from "./hdr";
 import type { Result } from "../result";
 import { err, ok } from "../result";
+import invariant from "../invariant";
 
 type Origin = {
   scheme: string;
@@ -41,7 +42,7 @@ let detectBin = async (): Promise<string> => {
 export let serve = async (
   initialConfig: RemixConfig,
   options: {
-    command: string;
+    command?: string;
     scheme: string;
     host: string;
     port: number;
@@ -83,19 +84,47 @@ export let serve = async (
   };
 
   let bin = await detectBin();
-  let startAppServer = (command: string) => {
-    console.log(`> ${command}`);
-    let newAppServer = execa.command(command, {
-      stdio: "pipe",
-      env: {
-        NODE_ENV: "development",
-        PATH:
-          bin + (process.platform === "win32" ? ";" : ":") + process.env.PATH,
-        REMIX_DEV_HTTP_ORIGIN: stringifyOrigin(origin),
-      },
-      // https://github.com/sindresorhus/execa/issues/433
-      windowsHide: false,
-    });
+  let startAppServer = (command?: string) => {
+    let cmd =
+      command ??
+      `remix-serve ${path.relative(
+        process.cwd(),
+        initialConfig.serverBuildPath
+      )}`;
+    console.log(`> ${cmd}`);
+    let newAppServer = execa
+      .command(cmd, {
+        stdio: "pipe",
+        env: {
+          NODE_ENV: "development",
+          PATH:
+            bin + (process.platform === "win32" ? ";" : ":") + process.env.PATH,
+          REMIX_DEV_HTTP_ORIGIN: stringifyOrigin(origin),
+        },
+        // https://github.com/sindresorhus/execa/issues/433
+        windowsHide: false,
+      })
+      .on("error", (e) => {
+        // patch execa error types
+        invariant("errno" in e && typeof e.errno === "number", "errno missing");
+        invariant("code" in e && typeof e.code === "string", "code missing");
+        invariant("path" in e && typeof e.path === "string", "path missing");
+
+        if (command === undefined) {
+          console.error(
+            [
+              "",
+              `┏ [error] command not found: ${e.path}`,
+              `┃ \`remix dev\` did not receive \`--command\` nor \`-c\`, defaulting to \`${cmd}\`.`,
+              "┃ You probably meant to use `-c` for your app server command.",
+              "┗ For example: `remix dev -c 'node ./server.js'`",
+              "",
+            ].join("\n")
+          );
+          process.exit(1);
+        }
+        throw e;
+      });
 
     if (newAppServer.stdin)
       process.stdin.pipe(newAppServer.stdin, { end: true });
@@ -164,10 +193,7 @@ export let serve = async (
         try {
           console.log(`Waiting for app server (${state.manifest?.version})`);
           let start = Date.now();
-          if (
-            options.command &&
-            (state.appServer === undefined || options.restart)
-          ) {
+          if (state.appServer === undefined || options.restart) {
             await kill(state.appServer);
             state.appServer = startAppServer(options.command);
           }