affected on an interface method never reaches the implementation: no method-level implements edge (PE-80043)

[filipechagas]

Filed from LawnStarter adoption ticket PE-80043 (api.lawnstarter.com), graded run at CLI 0.9.40, fork v8 @ 5e9d95c11837aeabbbb5d90cb45544f49dc58ca4.

Summary

graphify affected on an interface method never reaches the implementing method, at any depth. The graph records implements at the class level only; there is no method-level interface → implementation edge. So the single most important answer to "what breaks if I change this interface method?" — the class that implements it — is silently absent.

This is the "silent incompleteness" failure mode: no edge, no warning. The blast radius looks small and correct.

Reproduction

Corpus: api.lawnstarter.com @ 382fe1a2c1 (private LawnStarter repo, PHP/Laravel, 6,224 files).

Minimal shape:

// app/Repositories/ScheduleEvent/ScheduleEventRepository.php:138
interface ScheduleEventRepository
{
    public function bulkUpdateDistributionId(Collection $scheduleEvents, int $distributionId): void;
}

// app/Repositories/ScheduleEvent/DbScheduleEventRepository.php:71
class DbScheduleEventRepository extends DbRepository implements ScheduleEventRepository
{
    // :2106
    public function bulkUpdateDistributionId(Collection $scheduleEvents, int $distributionId): void { /* ... */ }
}

graphify update .
graphify affected "app_repositories_scheduleevent_scheduleeventrepository_scheduleeventrepository_bulkupdatedistributionid" --depth 2

Expected

Everything that breaks if that signature changes:

1. app/Repositories/ScheduleEvent/DbScheduleEventRepository.php:2106 — the implementing method
2. app/Actions/Distributions/BaseDistributionCreator.php:73 — the only production caller
3. app/Actions/Distributions/BaseDistributionCreator.php:47 — transitive, handle() calls bindEventsToDistribution()

Ground truth by grep, all 8 hits adjudicated. The 5 hits in BaseDistributionCreatorTest.php are Mockery shouldReceive('bulkUpdateDistributionId') string literals — correctly excluded as string mentions, and correctly absent from the output.

Actual

Affected nodes for .bulkUpdateDistributionId()
Relations: calls, indirect_call, references, imports, imports_from, re_exports, inherits, extends, implements, uses, mixes_in, embeds, requires
Depth: 2
- .bindEventsToDistribution() [calls] app/Actions/Distributions/BaseDistributionCreator.php:L73
- .handle() [calls] app/Actions/Distributions/BaseDistributionCreator.php:L47

2 of 3. The implementation is missing. --depth 3 returns byte-identical output, so raising depth does not help.

Note that implements is already in the traversed relation list — it just has nothing to traverse at method granularity.

Root cause

Inspecting graph.json directly:

=== iface method inbound ===
   calls  | .bindEventsToDistribution() | app/Actions/Distributions/BaseDistributionCreator.php L73
   method | ScheduleEventRepository     | app/Repositories/ScheduleEvent/ScheduleEventRepository.php L138

=== impl method inbound ===
   method | DbScheduleEventRepository   | app/Repositories/ScheduleEvent/DbScheduleEventRepository.php L2106

=== impl class -> iface class edges ===
   implements

The class-level implements edge exists. The two method nodes are connected to nothing but their own owning classes.

Suggestion

When class C implements I, emit an edge between C::m and I::m for each method name declared on I and defined on C — the match is purely by name within an already-established implements pair, so it needs no type inference. The same applies to abstract methods under inherits.

Failing that, having affected walk method -> owning class -> implements -> implementing class -> method of same name would recover it at traversal time.

[filipechagas]

Triage: pursue (high). Standalone graph-semantics unit: emit method-level implements edges inside proven implements pairs — a post-pass after PHP supertype canonicalization (resolution.py:2506, _PHP_SUPERTYPE_RELATIONS), composing with the fork #47 type-scoped method ids. This does not contradict the documented interface-receiver refusal (that policy governs call-site dispatch binding, not structural declaration edges), but the PR must say so explicitly and update docs/how-it-works.md. Needs corpus re-extraction.