Add incognito context support

[Niceplace]

Related issue : #81

• Add config parameter to set incognito mode (default: false)
• In environment setup, read from config and launch the page in incognito mode

Note: In headful mode, this seems to launch a separate chrome instance per tab as discussed here (apparently there's no performance overhead) : puppeteer/puppeteer#85 (comment)

I checked for unit tests if I needed to add any, it doesn't seem like it but please let me know if anything is wrong, I'll be happy to fix it !

[gregberge]

Several problems:

• Please put the option outside "launch" and rename it to "browserContext" (to activate "incognito" mode we will put browserContext: 'incognito'
• Please expose the global context even if not in "incognito" context
• Please update jest-environment-puppeteer readme and main readme about the new global context (don't forget ESLint section), the browserContext option and about a recipe for using "incognito" context and its advantages

[Niceplace]

Are you OK with explicitely checking this or you would rather just have else ? I would like to avoid allowing users to specify anything else than default or incognito

[Niceplace]

I'm going to need to do a bit more testing before I feel comfortable with this but please let me know if I'm on the right track with respect to your previous comments ! :)

[testerez]

Does it worth mentioning that? What about updating the peerDependancy: https://github.com/smooth-code/jest-puppeteer/blob/master/packages/jest-environment-puppeteer/package.json#L24

[testerez]

else {
    throw new Error(`browserContext should be either 'incognito' or 'default'. Received '${config.browserContext}' ')
}

[Niceplace]

@neoziro I'm ready for a second pass :D !

[gregberge]

This is not the right place for it, see below ### jest-puppeteer.config.js

[Niceplace]

Will fix soon ! Thanks for the feedback :) !

[gregberge]

It is actually a breaking change because there is no default value specified and all users will have an error.

Please consider it as default if not specified.

[Niceplace]

Will fix soon ! Thanks for the feedback :) !

[Niceplace]

I changed my implementation a bit, it felt easier to manage with a default value. If you think its inefficient please let me know I'll try to find a better solution.

[gregberge]

@Niceplace Thanks for your work, just a few comments.

[Niceplace]

@neoziro We have a problem :(

There seems to be some conflicts with expect-puppeteer, more specifically when we use expect(page).toMatchElement

I keep getting errors like this, "JSHandles can be evaluated only in the context they were created!"
We narrowed it down to this possible piece of code (packages/expect-puppeteer/src/matchers/toMatchElement.js) but some guidance would be appreciated. I do not know the extent of the impact, it could be in other functions / files as well

I think that when the executionContext is fetched, there should be some logic to check if we are in incognito mode ? I'm not really sure ...

export const getContext = async (instance, pageFunction) => {
  const type = getPuppeteerType(instance)
  switch (type) {
    case 'Page':
      return {
        page: instance,
        handle: await instance.evaluateHandle(pageFunction),
      }
    case 'ElementHandle': {
      const executionContext = await instance.executionContext()
      return {
        page: await executionContext.frame(),
        handle: instance,
      }
    }
    default:
      throw new Error(`${type} is not implemented`)
  }
}

[gregberge]

@Niceplace why closed?

[Niceplace]

@neoziro Hi Greg,

I'm not sure if this is the right way of doing things but at this point I don't feel I have the necessary abilities needed to finish this pull request, as mentioned in my previous message, I'm pretty much blocked and I'm not sure how to move forward from here.

If you want me to re-open it I can but someone else would need to take over.

Sorry about that. :-/

[gregberge]

@Niceplace ok thanks!