sql/no-client-schema is generated but never compiled #5

Corrected. The first version of this said nothing in the repository
generates with the flag on. That is wrong: entc/gen/graph_test.go builds a
graph with Features: AllFeatures, and #4 appended FeatureNoClientSchema to
that list, so TestGraph_Gen renders the flag-on templates on every
go test ./entc/gen/. The gap is narrower than stated and is below.

sql/no-client-schema (#4) drops Client.Schema and the <pkg>/migrate import
with it, so a binary that never migrates does not link Atlas.

What is covered

TestGraph_Gen runs graph.Gen() with every feature on, so the flag-on branch
of client.tmpl and enttest.tmpl is rendered, and Gen runs imports.Process
over the result (entc/gen/graph.go:1167). A template that fails to execute, or
that produces Go which does not parse, fails the test.

What is not

That test only os.Stats the files it expects. Nothing compiles them.

• A type error passes. enttest.tmpl renders migrate.NewSchema(c.Driver())
  under this flag; if Client.Driver() were renamed or its signature changed,
  the file would render, parse and format, and every job would stay green.
• A stale import passes silently, because imports.Process removes it rather
  than reporting it.

The generate job compiles nothing extra either — every package in this
repository is generated with the flag off, which is what that job pins.

What would close it

A small integration package generated with the flag on, alongside the ones
generated without it: a schema, a generate.go carrying the feature, and a test
that creates the schema the way a caller must under this flag.

if err := migrate.NewSchema(drv).Create(ctx); err != nil {
	...
}

Then both paths are compiled on every run and the generate job holds them both.

Also

entc/gen/template/migrate/migrate.tmpl:70 documents client.Schema.WriteTo in
a comment. Under this flag there is no client.Schema, so the example in the
generated package names something that package does not have.