Wrong test path pattern from CLI args

[seanpoulter]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?

1. When passing more than one --testPathPattern as command line arguments the test path pattern is wrong. The arg is typed as a string but multiple values mean the Array<string> is magically joined with , when the pattern is created by new RegExp(pattern, 'i').

   You can quickly see the pattern in the console by entering two paths that don't match:

   > jest aa bb
   ...
   Pattern: aa|bb
   
   > jest --testPathPattern=aa --testPathPattern=bb
   ...
   Pattern: aa,bb
   

2. When passing a --testPathPattern and an unnamed argument, they're not joined together. Again from the console:

   > jest aa --testPathPattern=bb
   ...
   Pattern: bb
   

What is the expected behavior?
Looks like we should:

• Update the arg type to be an Array<string>
• Join multiple testPathPattern args with |
• Join any testPathPattern args with the unnamed args

Please provide your exact Jest configuration and mention your Jest, node,
yarn/npm version and operating system.
Jest: 21.2.1
Code: Looking at the head of the master branch
Found while adding tests for #3793

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.