omit_unused_structs generates duplicate enum code

[josharian]

Version

Other

What happened?

v1.19.0 (not an option in the dropdown)

I added omit_unused_structs to our sqlc.yaml.

The resulting generated code included duplicate definitions for several enums, including type def, constants, methods, causing a compilation failure.

$ grep "^type" models.go | sort | uniq -c | grep -v 1 
   2 type CookingType string
   2 type HomeOwnershipType string
   2 type NullCookingType struct {
   2 type NullHomeOwnershipType struct {
   2 type NullSpaceHeatingType struct {
   2 type NullWaterHeatingType struct {
   2 type SpaceHeatingType string
   2 type WaterHeatingType string

Unfortunately, I can't reproduce using a trivial example in the playground, and I'm out of debugging time, so I'm filing this in the hopes that the problem is obvious from the symptoms.

Relevant log output

// none

Database schema

CREATE TYPE cooking_type AS ENUM(
	'gas',
	'electric',
	'induction',
	'other',
	'unknown'
);

SQL queries

No response

Configuration

version: 1
packages:
  - path: "."
    name: "sqlc"
    sql_package: "pgx/v5"
    engine: "postgresql"
    schema: "../migration"
    queries: // redacted
    emit_exact_table_names: true
    emit_enum_valid_method: true
    emit_all_enum_values: true
    emit_result_struct_pointers: true
    emit_params_struct_pointers: true
    omit_unused_structs: true

Playground URL

https://play.sqlc.dev/p/ec4ad0299744dc223ce2402ec06836dedc94d4cf2cf7727950c9e0f284132b44

What operating system are you using?

macOS

What database engines are you using?

PostgreSQL

What type of code are you generating?

Go

[kyleconroy]

I've attempted to reproduce here, no luck yet

[josharian]

drat. OK, i'll see about bisecting my way down to a reproducer. it may take me a while, there's a lot of code to chuck.

[josharian]

the good news is that that pull request fixes the issue. the bad news is that it exposes a new issue. have to eat dinner now, will file a new issue tomorrow.

[andrewmbenton]

Thanks for taking the time to try this @josharian. If the newly-exposed issue is related to duplicate enums feel free to reopen.

[josharian]

If the newly-exposed issue is related to duplicate enums feel free to reopen.

It turns out the new issue is that we were using one of the newly garbage collected enums in a jsonb schema definition Go struct type. However, we were not using it in any actual database table schemas. As a consequence the Go type for the enum got garbage collected. That seems pretty understandable. And the workaround is easy, if unfortunate: add a dummy placeholder that uses the enum type.

[josharian]

Actually, the placeholder db table isn't working for me well either. Oh well, I'll just live without this flag in that one spot for now. It's already a major improvement in the other places we use it.