tree c9dfe937b43b009790234cb55cc04ffaff3fa42a
parent 81b984d73508f49b340ec4de5c6b29e2fc903355
author Jonas Termansen <sortie@google.com> 1553253060 +0000
committer Jonas Termansen <sortie@google.com> 1553253060 +0000

[infra] Add support for pre-approvals in approved_results.json.

This change adds a 'preapprovals' field to approved_results.json, which is
a map from gerrit Change-Id values to a pre-approval record, containing:

* 'from': What the previous approval was.
* 'result': What the new approval is.
* 'matches': Whether the new approval matches the expectation.
* 'expected': The expectation for the new approval.
* 'preapprover': Who did the preapproval.
* 'preapproved_at': When the preapproval occurred.

tools/approve_results.dart now produces pre-approval records instead of
updating the actual approvals. This ensures pre-approvals don't take
effect immediately and fixes the problem of pre-approving one kind of
failure becoming another kind of failure. The script needed to query the
gerrit API in order to determine the Change-Id of changelists. This query
also lets approve_results know what the latest changelist and lifts the
restriction that the patchset must be supplied when pre-approving.

The innards of approve_results has been refactored so it better can handle
selective modification of approve_results.dart.

approve_results now also checks for race conditions with any other
concurrent approval in interactive mode. This should catch most cases where
people leave approve_results running for long. There still is a small race
condition, so there is no check done in the non-interactive mode as the
results would just have been downloaded anyway.

The new tools/bots/apply_preapprovals.dart script will be used by the
recipe. It locates the outstanding pre-approved changelists and checks
the git history for whether they have landed by searching for their
Change-Id. It then applies their pre-approvals in order, warning about any
merge conflicts. Optionally it uploads the pre-approvals. This will work
for the commit queue where the pre-approvals can be applied temporarily,
and in the continuous integration where the pre-approvals become permanent
approvals.

This change allows empty approval records that only contain preapprovals but
with no actual base approval. tools/bots/compare_results.dart has been
updared to handle that case.

This changelist addresses https://github.com/dart-lang/sdk/issues/36279 by
ensuring only verified fields make it into new approved_results.json records
and adds a temporary workaround for 14 days to remove existing needless
existing fields.

Change-Id: I7b3ff59756dc0d28721c6db480782b4ea983b55d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/97308
Reviewed-by: William Hesse <whesse@google.com>