feat(zero config): Support mutation testing without any configuration

[nicojs]

Adds support to mutation test simple projects without any configuration. Comparable to webpack 4's support for zero config. Adds the following sane defaults:

mutate: ['{src,lib}/**/*.js?(x)',
    '!{src,lib}/**/__tests__/**/*.js?(x)',
    '!{src,lib}/**/?(*.)+(spec|test).js?(x)',
    '!{src,lib}/**/*+(Spec|Test).js?(x)']`,
Coverage analysis: 'off'

Prior to this PR, the command test runner already became the default.

Fixes #1051

• Test runner: 'command'
• Mutator: "javascript" (not doing anymore, see comment below)
• Files to mutator: ['src/**/*.js', 'lib/**/*.js'] ['{src,lib}/**/*.js?(x)', '!{src,lib}/**/__tests__/**/*.js?(x)', '!{src,lib}/**/?(*.)+(spec|test).js?(x)', '!{src,lib}/**/*+(Spec|Test).js?(x)']
• Don't log a warning if one of the mutate patterns didn't result in files AND it is the default pattern.
• Coverage analysis: 'off' (it is 'perTest' now, but the CommandTestRunner does not support it)
• Document new default values in readme

[nicojs]

@stryker-mutator/contributors what do you guys think about leaving the mutator to "es5" for now? Update it when we release Stryker 1.0? To reduce the amount of breaking changes introduced by this PR

[mthmulders]

I would opt for keeping the number of breaking changes in this feature as low as possible.

[nicojs]

This PR is ready for review. @mthmulders @simondel @Archcry, welcome to take this.

[bartekleon]

@nicojs I understand this is zero tests for JS only? (no TS support I see)

[simondel]

Awesome :) On Dec 19, 2018 6:48 PM, "Bartosz Leoniak" <[email protected]> wrote: @nicojs <https://github.com/nicojs> I understand this is zero tests for JS only? (no TS support I see) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#1264 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AEBsLd0CIFa2WBsTVbt3A5bSqxL3AYvwks5u6nwJgaJpZM4Y8dQW> .

[nicojs]

Thanks for your review @mthmulders! I've implemented your review comments. Did you have a look at everything? If you're happy, I think we can merge it.

[nicojs]

Haha, sorry @mthmulders. We might need to need to revert back to my beautiful for statement. 😂

InputFileResolver
       when a globbing expression does not result in a result
         should not log a warning if the globbing expression was the default logging expression:
     TypeError: arr2.values is not a function

Node 6 doesn't support this magic. We're dropping node 6 support April 30th, so be patient.

EDIT: Apparently node 8 doesn't support it as well. April 30th 2020 is your day!