inherit defaultSeverity onto child configurations

[felschr]

PR checklist

• Addresses an existing issue: Overriding rule severity of recommended config preset is cumbersome and verbose #2569
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

As reported in #2569 setting the defaultSeverity in a configuration that extends another configuration (e.g. tslint:recommended) leaves the severity of the extended rules unchanged.

The changes in this pull-request make the defaultSeverity inherited from the top-most configuration to all underlying ones (by extends & ruleDirectory).

Is there anything you'd like reviewers to focus on?

This is mainly a quick for me personally but I'm open to improvement.
E.g. this could be activated only by a flag (e.g. --inheritDefaultSeverity).
Also some people in #2569 mentioned they'd like to completely override all defaults. This could also be added as a 2nd flag (e.g. --forceDefaultSeverity).

Depending on the feedback I can adjust the code and I'll also create new unit tests if necessary.

CHANGELOG.md entry:

[enhancement] inherit defaultSeverity onto child configurations

[palantirtech]

Thanks for your interest in palantir/tslint, @felschr! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[felschr]

I have no clue why the build failed. Can someone have a look at this?

test/rules/await-promise/custom-promise/test.ts.lint: Passed
      1) exits with code 0 if correct file is passed

test/rules/completed-docs/locations/test.ts.lint: Passed
      2) exits with code 0 if several files passed without `-f` flag

  130 passing (47s)
  2 failing

  1) Executable Files exits with code 0 if correct file is passed:
     Uncaught AssertionError: process should exit without an error: expected [Error: Command failed: /home/ubuntu/tslint/test/executable/npm-like-executable src/configuration.ts
[...]

UPDATE
oh, I found that there are multiple builds and some with errors that are understandable to me.

[felschr]

Sorry for all the commits regarding the style issues.
I edited the code on the GitHub website^^

[ajafff]

This also needs a test, Have a look at test/configurationTests.ts around line 280 for related tests

[ajafff]

IMO a defaultSeverity specified in the extending config file should always override the defaultSeverity in all extended configs.

[felschr]

Yep, that's should still be the case with my additions.

[ajafff]

Let's consider the following:

• a.json has no defaultSeverity
• b.json has defaultSeverity "warning"
• c.json extends a.json and b.json and has defaultSeverity "error"

The result is:

• rules specified in c.json get a default of "error"
• rules from b.json get a default of "warning", because b.json specifies its own defaultSeverity
• rules from a.json get a default of "error" from c.json, because a.json has no defaultSeverity.

To override the defaultSeverity in b.json, you'd need to adjust this line to

rawConfigFile.defaultSeverity = parentDefaultSeverity !== undefined ? parentDefaultSeverity : rawConfigFile.defaultSeverity;

To make it clearer what's happening here, I suggest to rename parentConfig to extendingConfig

[felschr]

@ajafff Thanks for directing me where to look.
I'll look into it this weekend.

[M0ns1gn0r]

@felschr Any progress on the PR? Our team experience the same problem and would really like the fix to be merged soon.

[felschr]

@M0ns1gn0r sorry, I wanted to do this but haven't really had time.
Can someone maybe help me with the configuration tests?

[jkillian]

Superseded by #3449