bug-fix-jest-addon-undefined-file-extension

[ghost]

Previously the code was such that the file name would always have an extension that read undefined this fixes that.

Issue:

What I did

We updated from v4.0.0-alpha.24 to v4.0.0-rc.0 and the unit tests no longer showed up for the jest addon. We dug into the code and quickly realized that the file extension will always be undefined in line 7 of the code because it isn't an object but a string.

How to test

Without this fix, see that jest test results do not show up, then update it and the test results should be available. (not sure if there were unit tests to make sure of this implementation)

Is this testable with Jest or Chromatic screenshots? No
Does this need a new example in the kitchen sink apps? No
Does this need an update to the documentation? No

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[renaudtertrais]

I am not sure to really understand the problem.
How to reproduce the issue ?
jestTestFilesOptions should be an object no ?

[ghost]

@renaudtertrais correct If you look at the code below

You will notice that on line 22 (https://github.com/storybooks/storybook/blob/master/addons/jest/src/index.js#L22 ) the last parameter is being sent in as a string (the file extension name).

However, on line 7 (https://github.com/storybooks/storybook/blob/master/addons/jest/src/index.js#L7) it is clearly expecting this to be an object which would make it undefined every time and the reason our tests stopped being included on the Tests tab in storybook.

Hope that explanation is a little bit more clear and gives insight to my change

[wuweiweiwu]

Nice fix