Upload target filesystem, Override File Naming

Thanks to #139 I can now handle the JSON and HTML reports locally without having to upload the results to an LHCI server (thanks for that!).

In order to programmatically handle the files generated, I’d like to be able to define a consistent pattern for the files. For example:

IF I run lchi collect --url=https://pantheon.io/docs --url=https://some.staging.environment.io/docs, AND I define some extra parameter like --format=$URL-$PASS_NUM (just spit-balling on this) THEN the contents of .lighthouseci would look like:

.lighthouseci
|- lhr-https://pantheon.io/docs-1.html
|- lhr-https://pantheon.io/docs-1.json
|- lhr-https://pantheon.io/docs-2.html
|- lhr-https://pantheon.io/docs-2.json
|- lhr-https://pantheon.io/docs-3.html
|- lhr-https://pantheon.io/docs-3.json
|- lhr-https://some.staging.environment.io/docs-1.html
|- lhr-https://some.staging.environment.io/docs-1.json
|- lhr-https://some.staging.environment.io/docs-2.html
|- lhr-https://some.staging.environment.io/docs-2.json
|- lhr-https://some.staging.environment.io/docs-3.html
|- lhr-https://some.staging.environment.io/docs-3.json

Not that the filename needs to contain the full URL, this is just an example where it uses a parameter already defined in another flag. Anything consistently predictable would suite my needs.

[patrickhulce]

Thanks for the offer @staceytay! This is a slightly larger unscoped effort that has some interplay with breaking changes in #119 though, so I’m not sure it’s a great candidate for external PR help at the moment.

FWIW, all of the data is available for the GH action to build this output themselves. If we just agree on an interface for the manifest then there’s no need for this to block that issue.

How does everyone feel about…

interface EntrySummary {
  performance: number // all category scores on 0-1 scale
  accessibility: number
  'best-practices': number
  seo: number
  pwa: number
}

interface Entry {
  url: string // finalUrl of the run
  isRepresentativeRun: boolean // whether it was the median run for the URL
  jsonPath: string
  htmlPath: string
  summary: EntrySummary
}

// Manifest contains an array of entries, 1 for each run. 
// Let's say all are included by default, skipping over the `--include-all-reports` bit.
type Manifest = Array<Entry>

// Alternative, we group the entries by url
type Manifest = Record<string, Array<Entry>> 

[patrickhulce]

Quick poll on the expected behavior if manifest.json already exists in the target folder, should LHCI…

🚀 overwrite it 😕 throw an error and bail