feat(e2e-runner): enable or disable target logging via options (#203)

Use the new `logging` option on a target to either enable, or disable
the logging output for the specified target.

Closes #202

I tried adding some component tests; but I can't seem to mock
`child_process.spawn` properly without adding extra libraries.

packages/e2e-runner/README.md

@@ -34,6 +34,7 @@ Each target can be configured with the following options.
   env?: { [key: string]: string } // Extra parameters provided to the target on startup.
   reuseExistingServer?: boolean // Set to true to allow using a previously started target.
   rejectUnauthorized?: boolean // Set to false to allow the use of self-signed certificates in your target.
+  logging?: boolean // Set to true to forwards the logs of the target, set to false to hide the logs of the target. When undefined, the logs are only forwarded with the `--verbose` flag.
 }
 ```
 
@@ -56,7 +57,8 @@ Example target
         {
           "target": "api:serve",
           "checkUrl": "http://localhost:9000/health",
-          "checkMaxTries": 50
+          "checkMaxTries": 50,
+          "logging": false
         }
       ]
     }

packages/e2e-runner/src/executors/run/utils/nx-target.ts

@@ -13,6 +13,7 @@ export interface NxTargetOptions {
   env?: { [key: string]: string }
   reuseExistingServer?: boolean
   rejectUnauthorized?: boolean
+  logging?: boolean
 }
 
 export class NxTarget {
@@ -101,7 +102,8 @@ export class NxTarget {
       onExit: (code) => (
         processExitedReject(new Error(`Target "${this.options.target}" was not able to start. Exit code: ${code}`))
       ),
-      env: this.options.env
+      env: this.options.env,
+      logging: this.options.logging
     })
 
     if (this.killed) {
@@ -162,10 +164,13 @@ function launchProcess(
   options: {
     onExit: (exitCode: number | null, signal: string | null) => void
     env?: { [key: string]: string }
+    logging?: boolean
   }
 ): () => Promise<void> {
   const { project, target, configuration } = parseTargetString(targetString, readCachedProjectGraph())
 
+  const shouldLog = options.logging ?? USE_VERBOSE_LOGGING
+
   const spawnedProcess = childProcess.spawn(
     `${getPackageManagerExecCommand()} nx ${target} ${project} ${
       configuration ? `--configuration=${configuration}` : ''
@@ -175,7 +180,7 @@ function launchProcess(
       detached: true,
       shell: true,
       cwd: process.cwd(),
-      stdio: USE_VERBOSE_LOGGING ? 'inherit' : undefined,
+      stdio: shouldLog ? 'inherit' : undefined,
       env: {
         ...process.env,
         // Make sure NODE_ENV is set to test