chore: statically extract .proto from Go source (#2973)

This adds a general purpose command `go2proto` that statically generates
a `.proto` file from Go source code. This used to be done via
reflection, but that resulted in a chicken and egg problem whereby the
reflection code needed to be compilable in order to generate the
protobuf files that the reflection code depended on.

A couple of minor side-effects:

1. This will automatically extract sum types and enums.
2. The runtime types have been moved directly into the schema, as
opposed to only existing in the proto.
3. Sum type elements will need to be tagged with a `//protobuf:<id>`
directive.

These are the breaking changes:

```
backend/protos/xyz/block/ftl/v1/schema/schema.proto:43:26:Field "5" on message "Data" changed name from "typeParameters" to "type_parameters".
backend/protos/xyz/block/ftl/v1/schema/schema.proto:162:3:Field "2" with name "kind" on message "MetadataAlias" changed type from "int64" to "enum".
backend/protos/xyz/block/ftl/v1/schema/schema.proto:197:10:Field "3" on message "MetadataRetry" changed name from "minBackoff" to "min_backoff".
backend/protos/xyz/block/ftl/v1/schema/schema.proto:198:10:Field "4" on message "MetadataRetry" changed name from "maxBackoff" to "max_backoff".
backend/protos/xyz/block/ftl/v1/schema/schema.proto:210:10:Field "3" on message "MetadataTypeMap" changed name from "nativeName" to "native_name".
backend/protos/xyz/block/ftl/v1/schema/schema.proto:245:17:Field "4" on message "Ref" changed name from "typeParameters" to "type_parameters".
backend/protos/xyz/block/ftl/v1/schema/schema.proto:350:3:Field "3" with name "status" on message "VerbRuntime" changed type from "xyz.block.ftl.v1.schema.Status" to "xyz.block.ftl.v1.schema.VerbStatus".
```

None of these changes should effect wire compatibility.

Fixes #2935

.go-arch-lint.yml

@@ -19,7 +19,7 @@ components:
   frontend: { in: frontend/console/** }
   ftl-gen-lsp-cmd: { in: cmd/ftl-gen-lsp/** }
   ftl-initdb-cmd: { in: cmd/ftl-initdb/** }
-  ftl-schema-cmd: { in: cmd/ftl-schema/** }
+  go2proto: { in: cmd/go2proto/** }
   lint-commit-or-rollback-cmd: { in: cmd/lint-commit-or-rollback/** }
   databasetesting: { in: backend/controller/sql/databasetesting/** }
   sql: { in: backend/controller/sql/** }

.golangci.yml

@@ -101,7 +101,6 @@ linters-settings:
   #   ignorePackageGlobs:
   #     - github.com/TBD54566975/ftl/*
   spancheck:
-
     extra-start-span-signatures:
       - "github.com/TBD54566975/ftl/backend/controller/observability.BeginSpan:opentelemetry"
 issues:
@@ -143,3 +142,4 @@ issues:
     - "strings.Title has been deprecated"
     - "error returned from external package is unwrapped.*TranslatePGError"
     - "struct literal uses unkeyed fields"
+    - "exported: comment on exported type"

Justfile

@@ -129,12 +129,12 @@ pnpm-install:
 
 # Regenerate protos
 build-protos: pnpm-install
-  @mk {{SCHEMA_OUT}} : internal/schema -- "ftl-schema > {{SCHEMA_OUT}} && buf format -w && buf lint"
+  @mk {{SCHEMA_OUT}} : internal/schema -- "go2proto -o "{{SCHEMA_OUT}}" -g 'github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v1/schema;schemapb' xyz.block.ftl.v1.schema ./internal/schema.Schema && buf format -w && buf lint"
   @mk {{PROTOS_OUT}} : {{PROTOS_IN}} -- "cd backend/protos && buf generate"
 
 # Unconditionally rebuild protos
 build-protos-unconditionally: pnpm-install
-  ftl-schema > {{SCHEMA_OUT}} && buf format -w && buf lint
+  go2proto -o "{{SCHEMA_OUT}}" -g 'github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v1/schema;schemapb' xyz.block.ftl.v1.schema ./internal/schema.Schema && buf format -w && buf lint
   cd backend/protos && buf generate
 
 # Run integration test(s)

backend/controller/ingress/ingress_test.go

@@ -119,7 +119,7 @@ func TestValidation(t *testing.T) {
 		{name: "IntAlias",
 			schema: `module test {
 			typealias IntAlias Int
-			data Test { intValue test.IntAlias } 
+			data Test { intValue test.IntAlias }
 			}`,
 			request: obj{"intValue": 10.0},
 		},
@@ -245,7 +245,7 @@ func TestResponseBodyForVerb(t *testing.T) {
 					&schema.Data{
 						Name: "Test",
 						Fields: []*schema.Field{
-							{Name: "message", Type: &schema.String{}, Metadata: []schema.Metadata{&schema.MetadataAlias{Kind: schema.AliasKindJSON, Alias: "msg"}}},
+							{Name: "message", Type: &schema.String{}, Metadata: []schema.Metadata{&schema.MetadataAlias{Kind: schema.AliasKindJson, Alias: "msg"}}},
 						},
 					},
 					jsonVerb,

backend/controller/ingress/request.go

@@ -312,7 +312,7 @@ func parseQueryParams(values url.Values, data *schema.Data) (map[string]any, err
 
 		var field *schema.Field
 		for _, f := range data.Fields {
-			if jsonAlias, ok := f.Alias(schema.AliasKindJSON).Get(); (ok && jsonAlias == key) || f.Name == key {
+			if jsonAlias, ok := f.Alias(schema.AliasKindJson).Get(); (ok && jsonAlias == key) || f.Name == key {
 				field = f
 			}
 			for _, typeParam := range data.TypeParameters {

backend/controller/ingress/response.go

@@ -80,7 +80,7 @@ func bodyForType(typ schema.Type, sch *schema.Schema, data []byte) ([]byte, erro
 		}
 
 		err = schema.TransformAliasedFields(sch, t, response, func(obj map[string]any, field *schema.Field) string {
-			if jsonAlias, ok := field.Alias(schema.AliasKindJSON).Get(); ok && field.Name != jsonAlias {
+			if jsonAlias, ok := field.Alias(schema.AliasKindJson).Get(); ok && field.Name != jsonAlias {
 				obj[jsonAlias] = obj[field.Name]
 				delete(obj, field.Name)
 				return jsonAlias