feat: add reject option

Author: aleclarson

src/index.d.ts

@@ -2,11 +2,15 @@ import { ChildProcess, SpawnOptions } from 'child_process';
 
 interface ExtendOptions extends SpawnOptions {
   json?: boolean;
+  reject?: boolean;
 }
 
 interface ResolvedSubprocess extends Omit<ChildProcess, 'stdout' | 'stderr'> {
   stdout: string;
   stderr: string;
+  exitCode: number;
+  /** Only exists if `reject` was false and the child process exited with a non-zero code. */
+  error?: Error;
 }
 
 export interface SubprocessPromise extends Promise<ResolvedSubprocess>, ChildProcess {}

src/index.js

@@ -58,9 +58,14 @@ const extend = defaults => (input, args, options) => {
         get: parse(stdout, opts)
       })
       Object.defineProperty(childProcess, 'stderr', { get: parse(stderr) })
-      return exitCode === 0
-        ? resolve(childProcess)
-        : reject(createChildProcessError({ cmd, cmdArgs, childProcess }))
+      if (exitCode !== 0) {
+        const error = createChildProcessError({ cmd, cmdArgs, childProcess })
+        if (opts.reject !== false) {
+          return reject(error)
+        }
+        childProcess.error = error
+      }
+      return resolve(childProcess)
     })
   })