Ignore errors in unreachable modules

robhogan commented 11 months ago

Summary: Currently, if Metro encounters an error resolving a dependency or transforming a module that is present in the graph at the time the error is introduced, it will return the error to the client and continue to do so, even after the bad dependency is subsequently made unreachable by another change.

This is "fixed" by a full refresh or Metro restart, because a new traversal would not encounter the error, and is therefore a correctness bug.

This diff fixes the bug by:

Collecting, instead of immediately throwing on, transform and resolution errors during buildSubgraph (prior to any state modification).
If there are errors, take a snapshot of all of the modified modules at the base state.
Commit removals only, skipping modified modules with errors, and collect cycles (the "subtractive pass") - this should never fail.
Try to commit new and modified dependencies starting from the modified modules still present in the graph (the "additive pass"). Any error caught here corresponds to a reachable error the user must action.
On catching an error, commit the base state we captured earlier, rolling the graph back, and re-throw the error.

Changelog:

**[Fix]**: Ignore errors in unreachable modules during incremental builds.

Reviewed By: motiz88

Differential Revision: D52457312

facebook-github-bot commented 11 months ago

This pull request was exported from Phabricator. Differential Revision: D52457312

facebook-github-bot commented 11 months ago

This pull request was exported from Phabricator. Differential Revision: D52457312

facebook-github-bot commented 11 months ago

This pull request was exported from Phabricator. Differential Revision: D52457312

facebook-github-bot commented 11 months ago

This pull request has been merged in facebook/metro@698b13e8788017d7384132b10a4381c7582d7f02.

facebook / metro

Ignore errors in unreachable modules #1164