fix(gatsby): only enable debugger when argument is given (#26669)

Author: wardpeet

packages/gatsby-cli/src/create-cli.ts

@@ -175,17 +175,23 @@ function buildLocalCommands(cli: yargs.Argv, isLocalSite: boolean): void {
         .option(`inspect`, {
           type: `number`,
           describe: `Opens a port for debugging. See https://www.gatsbyjs.org/docs/debugging-the-build-process/`,
-          default: 9229,
         })
         .option(`inspect-brk`, {
           type: `number`,
           describe: `Opens a port for debugging. Will block until debugger is attached. See https://www.gatsbyjs.org/docs/debugging-the-build-process/`,
-          default: 9229,
         }),
     handler: handlerP(
       getCommandHandler(`develop`, (args: yargs.Arguments, cmd: Function) => {
         process.env.NODE_ENV = process.env.NODE_ENV || `development`
         startGraphQLServer(siteInfo.directory, true)
+
+        if (args.hasOwnProperty(`inspect`)) {
+          args.inspect = args.inspect || 9229
+        }
+        if (args.hasOwnProperty(`inspect-brk`)) {
+          args.inspect = args.inspect || 9229
+        }
+
         cmd(args)
         // Return an empty promise to prevent handlerP from exiting early.
         // The development server shouldn't ever exit until the user directly

packages/gatsby/src/commands/develop.ts

@@ -100,11 +100,11 @@ class ControllableScript {
     const args = [tmpFileName]
     // Passing --inspect isn't necessary for the child process to launch a port but it allows some editors to automatically attach
     if (this.debugInfo) {
-      args.push(
-        this.debugInfo.break
-          ? `--inspect-brk=${this.debugInfo.port}`
-          : `--inspect=${this.debugInfo.port}`
-      )
+      if (this.debugInfo.break) {
+        args.push(`--inspect-brk=${this.debugInfo.port}`)
+      } else {
+        args.push(`--inspect=${this.debugInfo.port}`)
+      }
     }
 
     this.process = spawn(`node`, args, {