Cli: improve Next.js project detection (#262)

* Detect presence of a “next” dependency

* Use a strict undefined check instead

* Changeset: Detect Next.js project by looking at dependencies, not next.config.js

* Read a package json file

* First check for next.config file, otherwise use next dependency

* Update changeset description

.changeset/unlucky-wombats-scream.md

@@ -0,0 +1,5 @@
+---
+"@trigger.dev/cli": patch
+---
+
+Detect Next.js project by looking at dependencies if can't find next.config.js

packages/cli/src/utils/detectNextJsProject.ts

@@ -1,15 +1,29 @@
 import fs from "fs/promises";
 import pathModule from "path";
+import { readPackageJson } from "./readPackageJson.js";
 
 /** Detects if the project is a Next.js project at path  */
 export async function detectNextJsProject(path: string): Promise<boolean> {
-  // Checks for the presence of a next.config.js file
-  try {
-    // Check if next.config.js file exists in the given path
-    await fs.access(pathModule.join(path, "next.config.js"));
+  const hasNextConfigFile = await detectNextConfigFile(path);
+  if (hasNextConfigFile) {
     return true;
-  } catch (error) {
-    // If next.config.js file doesn't exist, it's not a Next.js project
+  }
+
+  return await detectNextDependency(path);
+}
+
+async function detectNextConfigFile(path: string): Promise<boolean> {
+  return fs
+    .access(pathModule.join(path, "next.config.js"))
+    .then(() => true)
+    .catch(() => false);
+}
+
+async function detectNextDependency(path: string): Promise<boolean> {
+  const packageJsonContent = await readPackageJson(path);
+  if (!packageJsonContent) {
     return false;
   }
+
+  return packageJsonContent.dependencies?.next !== undefined;
 }

packages/cli/src/utils/readPackageJson.ts

@@ -0,0 +1,10 @@
+import pathModule from "path";
+import { type PackageJson } from "type-fest";
+import { readJSONFile } from "./fileSystem.js";
+
+export async function readPackageJson(directory: string): Promise<PackageJson | undefined> {
+  const packageJsonPath = pathModule.join(directory, "package.json");
+  return readJSONFile(packageJsonPath)
+    .then((f) => f as PackageJson)
+    .catch(() => undefined);
+}