feat(lambda-at-edge, nextjs-component, s3-static-assets): support ver…

[dphang]

…sioned static pages (currently only next data is versioned) for proper fallback SSG generation, never cache fallback pages

• This will create versioned static pages directory for assets e.g static-pages/build1, static-pages/build2. It also copies the BUILD_ID file to assets/BUILD_ID or assets/basepath/BUILD_ID to represent the current latest version that was just uploaded to S3.
• When the BUILD_ID file is present in S3, it uses it and the AWS S3 SDK to clear all previous build versions of _next/data/<build_id> and static-pages/<build_id> except the version in BUILD_ID. It doesn't remove existing pages in the root static-pages directory, so it won't be destructive when transitioning from old to new Lambda versions. This happens before the S3 upload of the new build version. Then once the new S3 assets are uploaded, only the new + previous build versions are present. This is to help us save on S3 storage costs and ensure Lambda doesn't break on deployment transitions.
• This (along with cache control fixes) is needed to fix fallback SSG generation, as currently fallback pages are not versioned and put into static-pages/pages.html. This never gets deleted, so subsequent deployments may be getting an old generated page for an SSG fallback. By using versioned pages instead, we can ensure that it gets updated (and old ones get cleared after deployments).
• Versioning pages could also fix a general issue (not fallback specific) where when transitioning between Lambda deployments, a newer version's page is served (via S3) by an older Lambda, due to S3 uploading finishing before the newer Lambda could propagate, which could possibly cause issues (but probably rare?)
• Fallback pages are never cached (Cache-Control in both rendering + S3 upload is set to no-store) and now can also use the versioned pages properly.

Tests

Updated unit and e2e tests. Added tests for new S3 removal method for both with and without basePath.

[codecov]

Codecov Report

Merging #803 (1b585bf) into master (8d384cf) will increase coverage by 0.30%.
The diff coverage is 93.22%.

@@            Coverage Diff             @@
##           master     #803      +/-   ##
==========================================
+ Coverage   80.23%   80.54%   +0.30%     
==========================================
  Files          57       57              
  Lines        1862     1912      +50     
  Branches      410      422      +12     
==========================================
+ Hits         1494     1540      +46     
- Misses        310      313       +3     
- Partials       58       59       +1     

Impacted Files	Coverage Δ
...ackages/libs/lambda-at-edge/src/default-handler.ts	94.02% <66.66%> (-0.76%)	⬇️
packages/libs/s3-static-assets/src/lib/s3.ts	95.23% <96.66%> (+3.57%)	⬆️
packages/libs/lambda-at-edge/src/build.ts	91.56% <100.00%> (+0.06%)	⬆️
packages/libs/s3-static-assets/src/index.ts	100.00% <100.00%> (ø)
...ackages/libs/s3-static-assets/src/lib/constants.ts	100.00% <100.00%> (ø)
...rless-components/nextjs-component/src/component.ts	90.60% <100.00%> (+0.06%)	⬆️
...ibs/s3-static-assets/src/lib/readDirectoryFiles.ts	88.88% <0.00%> (-11.12%)	⬇️

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[danielcondemarin]

LGTM 👍