fix: path can being falsy

[ndelangen]

I'm running into this:

WARNING in ./src/stories/components/ButtonTs.vue
Module Warning (from /Users/dev/Projects/GitHub/storybook/core/node_modules/vue-docgen-loader/lib/index.js):
[vue-docgen-loader] failed to parse the component file with docgen-api: Cannot read property 'leadingComments' of null
 @ ./src/stories/components/button-ts.stories.js 54:0-38 82:13-21 87:16-24
 @ ./src/stories sync ^\.(?:(?:^|\/|(?:(?:(?!(?:^|\/)\.).)*?)\/)(?!\.)(?=.)[^/]*?\.stories\.(js|mdx))$
 @ ./.storybook/generated-stories-entry.js
 @ multi /Users/dev/Projects/GitHub/storybook/core/lib/core/dist/server/common/polyfills.js /Users/dev/Projects/GitHub/storybook/core/lib/core/dist/server/preview/globals.js ./.storybook/storybook-init-framework-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/docs/dist/frameworks/common/config.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/docs/dist/frameworks/vue/config.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/actions/dist/preset/addDecorator.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/actions/dist/preset/addArgs.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/links/dist/preset/addDecorator.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/knobs/dist/preset/addDecorator.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/backgrounds/dist/preset/addDecorator.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/backgrounds/dist/preset/addParameter.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/a11y/dist/a11yRunner.js-generated-other-entry.js /Users/dev/Projects/GitHub/storybook/core/addons/a11y/dist/a11yHighlight.js-generated-other-entry.js ./.storybook/preview.js-generated-config-entry.js ./.storybook/generated-stories-entry.js (webpack)-hot-middleware/client.js?reload=true&quiet=false&noInfo=undefined

can be seen here:
https://app.circleci.com/pipelines/github/storybookjs/storybook/15225/workflows/61a1c1db-3033-4aa0-b6dd-55e171344580/jobs/281856

Seems related to #753 & storybookjs/storybook#9745

Fix in a different file seems related:
1d3d29e

Here's the PR I'm working on in storybook:
storybookjs/storybook#13289

thank you for your time and consideration 🙇

[codecov]

Codecov Report

Merging #1029 (799e6f3) into dev (bf42ccc) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##              dev    #1029   +/-   ##
=======================================
  Coverage   63.69%   63.69%           
=======================================
  Files         178      178           
  Lines        4873     4873           
  Branches     1440     1441    +1     
=======================================
  Hits         3104     3104           
  Misses       1697     1697           
  Partials       72       72           

Impacted Files	Coverage Δ
packages/vue-docgen-api/src/utils/getDocblock.ts	100.00% <100.00%> (ø)

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[elevatebart]

Thank you @ndelangen for taking the time to create a PR here.
I believe what you are trying to fix is already fixed by the build coming up in a few minutes.

check out this issue #1027 for which I added those tests:

vue-styleguidist/packages/vue-docgen-api/src/script-handlers/__tests__/componentHandler.ts

Lines 186 to 194 in bf42ccc

	it('should not fail when no comments are on a Vue.extends', () => {
	const src = `export default Vue.extends({})`
	const def = parse(src).get('default')
	expect(() => {
	if (def) {
	componentHandler(documentation, def)
	}
	}).not.toThrow()
	})

and a fix.