Passthrough Copy should always be incremental

[zachleat]

While incremental for passthrough copy is shipping via #977 in 0.11.0, I think a very strong case can be made to always use incremental behavior for passthrough copy files, specifically:

1. When a passthrough copy file changes during watch, just copy the one file (no other templates are processed)
2. When a template changes that is not a passthrough copy file during watch, the passthrough copy file is not copied.

[marcfilleul]

+1

[tarasis]

Does incremental with passthrough copy only work with WATCH or SERVE? Atm it seems the --incremental doesn't work on its own. Which means each new update (for now) copies 190 files needlessly. Sure its done in ½ a second but its wear and tear that isn't needed.

My ideal it push changes to server, it checks out the new head, builds incrementally (aka only builds what's changed) and then that's served.

[11ty] Copied 190 files / Wrote 2 files in 0.41 seconds (v1.0.0)

[zachleat]

A better resolution to this issue will be shipping with 2.0.0-canary.12: #2456

Works in both --incremental and standard modes.

[zachleat]

@tarasis sorry to circle back here late but that feature requires Cold Start incremental, which is on the roadmap! Subscribe to #984

[zachleat]

Note that this feature was swapped to opt-in in 2.0.0-canary.31: https://fosstodon.org/@eleventy/109705218587201477