fix: correctly generate schema files (#3844)

backend/protos/xyz/block/ftl/language/v1/language.proto

@@ -103,9 +103,6 @@ message ModuleConfigDefaultsResponse {
   // Build lock path to prevent concurrent builds
   optional string build_lock = 4;
 
-  // Default relative path to the directory containing generated schema files
-  optional string generated_schema_dir = 5;
-
   // Default patterns to watch for file changes, relative to the module directory
   repeated string watch = 6;
 
@@ -289,6 +286,9 @@ message SyncStubReferencesRequest {
 
   // The names of all modules that have had stubs generated
   repeated string modules = 3;
+
+  // The complete FTL schema
+  ftl.schema.v1.Schema schema = 4;
 }
 
 message SyncStubReferencesResponse {}

common/schema/schema_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/alecthomas/assert/v2"
+	"golang.org/x/exp/maps"
 
 	"github.com/block/ftl/common/errors"
 	"github.com/block/ftl/common/slices"
@@ -1050,3 +1051,27 @@ func TestParseTypeMap(t *testing.T) {
 	actual = Normalise(actual)
 	assert.Equal(t, testSchema.Modules[4], actual, assert.Exclude[Position]())
 }
+
+func TestModuleDependencies(t *testing.T) {
+	input := `
+// A comment
+module a {
+  export verb m(Unit) Unit
+  	+calls b.m
+}
+module b {
+  export verb m(Unit) Unit
+  	+calls c.m
+}
+module c {
+  export verb m(Unit) Unit
+}
+`
+	actual, err := ParseString("", input)
+	assert.NoError(t, err)
+	actual = Normalise(actual)
+	assert.Equal(t, []string{"b", "c"}, maps.Keys(actual.ModuleDependencies("a")))
+	assert.Equal(t, []string{"c"}, maps.Keys(actual.ModuleDependencies("b")))
+	assert.Equal(t, []string{}, maps.Keys(actual.ModuleDependencies("c")))
+
+}

examples/java/time/src/main/java/ftl/time/Time.java

@@ -12,4 +12,10 @@ public class Time {
     public TimeResponse time() {
         return new TimeResponse(OffsetDateTime.now().plusDays(1));
     }
+
+    @Verb
+    @Export
+    public TimeResponse time2() {
+        return new TimeResponse(OffsetDateTime.now().plusDays(1));
+    }
 }

go-runtime/goplugin/service_test.go

@@ -114,12 +114,11 @@ func TestGoConfigDefaults(t *testing.T) {
 
 func defaultsFromProto(proto *langpb.ModuleConfigDefaultsResponse) moduleconfig.CustomDefaults {
 	return moduleconfig.CustomDefaults{
-		DeployDir:          proto.DeployDir,
-		Watch:              proto.Watch,
-		Build:              optional.Ptr(proto.Build),
-		DevModeBuild:       optional.Ptr(proto.DevModeBuild),
-		GeneratedSchemaDir: optional.Ptr(proto.GeneratedSchemaDir),
-		LanguageConfig:     proto.LanguageConfig.AsMap(),
-		SQLMigrationDir:    proto.SqlMigrationDir,
+		DeployDir:       proto.DeployDir,
+		Watch:           proto.Watch,
+		Build:           optional.Ptr(proto.Build),
+		DevModeBuild:    optional.Ptr(proto.DevModeBuild),
+		LanguageConfig:  proto.LanguageConfig.AsMap(),
+		SQLMigrationDir: proto.SqlMigrationDir,
 	}
 }

internal/buildengine/engine.go

@@ -913,7 +913,7 @@ func (e *Engine) buildWithCallback(ctx context.Context, callback buildCallback,
 		}
 
 		// Sync references to stubs if needed by the runtime
-		err = SyncStubReferences(ctx, e.projectConfig.Root(), moduleNames, metasMap)
+		err = SyncStubReferences(ctx, e.projectConfig.Root(), moduleNames, metasMap, &schema.Schema{Modules: maps.Values(builtModules)})
 		if err != nil {
 			return err
 		}

internal/buildengine/languageplugin/plugin.go

@@ -241,14 +241,13 @@ func (p *LanguagePlugin) ModuleConfigDefaults(ctx context.Context, dir string) (
 
 func customDefaultsFromProto(proto *langpb.ModuleConfigDefaultsResponse) moduleconfig.CustomDefaults {
 	return moduleconfig.CustomDefaults{
-		DeployDir:          proto.DeployDir,
-		Watch:              proto.Watch,
-		Build:              optional.Ptr(proto.Build),
-		DevModeBuild:       optional.Ptr(proto.DevModeBuild),
-		BuildLock:          optional.Ptr(proto.BuildLock),
-		GeneratedSchemaDir: optional.Ptr(proto.GeneratedSchemaDir),
-		LanguageConfig:     proto.LanguageConfig.AsMap(),
-		SQLMigrationDir:    proto.SqlMigrationDir,
+		DeployDir:       proto.DeployDir,
+		Watch:           proto.Watch,
+		Build:           optional.Ptr(proto.Build),
+		DevModeBuild:    optional.Ptr(proto.DevModeBuild),
+		BuildLock:       optional.Ptr(proto.BuildLock),
+		LanguageConfig:  proto.LanguageConfig.AsMap(),
+		SQLMigrationDir: proto.SqlMigrationDir,
 	}
 }
 
@@ -300,7 +299,7 @@ func (p *LanguagePlugin) GenerateStubs(ctx context.Context, dir string, module *
 // import the modules when users start reference them.
 //
 // It is optional to do anything with this call.
-func (p *LanguagePlugin) SyncStubReferences(ctx context.Context, config moduleconfig.ModuleConfig, dir string, moduleNames []string) error {
+func (p *LanguagePlugin) SyncStubReferences(ctx context.Context, config moduleconfig.ModuleConfig, dir string, moduleNames []string, view *schema.Schema) error {
 	configProto, err := langpb.ModuleConfigToProto(config.Abs())
 	if err != nil {
 		return fmt.Errorf("could not create proto for native module config: %w", err)
@@ -309,6 +308,7 @@ func (p *LanguagePlugin) SyncStubReferences(ctx context.Context, config moduleco
 		StubsRoot:    dir,
 		Modules:      moduleNames,
 		ModuleConfig: configProto,
+		Schema:       view.ToProto(),
 	}))
 	if err != nil {
 		return fmt.Errorf("plugin failed to sync stub references: %w", err)

internal/buildengine/stubs.go

@@ -45,14 +45,13 @@ func CleanStubs(ctx context.Context, projectRoot string) error {
 // SyncStubReferences syncs the references in the generated stubs.
 //
 // For Go, this means updating all the go.work files to include all known modules in the shared stubbed modules directory.
-func SyncStubReferences(ctx context.Context, projectRoot string, moduleNames []string, metas map[string]moduleMeta) error {
+func SyncStubReferences(ctx context.Context, projectRoot string, moduleNames []string, metas map[string]moduleMeta, view *schema.Schema) error {
 	wg, wgctx := errgroup.WithContext(ctx)
 	for _, meta := range metas {
 		stubsRoot := stubsLanguageDir(projectRoot, meta.module.Config.Language)
-		if err := meta.plugin.SyncStubReferences(wgctx, meta.module.Config, stubsRoot, moduleNames); err != nil {
+		if err := meta.plugin.SyncStubReferences(wgctx, meta.module.Config, stubsRoot, moduleNames, view); err != nil {
 			return err //nolint:wrapcheck
 		}
-		return nil
 	}
 	err := wg.Wait()
 	if err != nil {

internal/moduleconfig/moduleconfig.go

@@ -56,12 +56,11 @@ type AbsModuleConfig ModuleConfig
 type UnvalidatedModuleConfig ModuleConfig
 
 type CustomDefaults struct {
-	DeployDir          string
-	Watch              []string
-	BuildLock          optional.Option[string]
-	Build              optional.Option[string]
-	DevModeBuild       optional.Option[string]
-	GeneratedSchemaDir optional.Option[string]
+	DeployDir    string
+	Watch        []string
+	BuildLock    optional.Option[string]
+	Build        optional.Option[string]
+	DevModeBuild optional.Option[string]
 
 	// only the root keys in LanguageConfig are used to find missing values that can be defaulted
 	LanguageConfig map[string]any `toml:"-"`

internal/moduleconfig/moduleconfig_test.go

@@ -22,12 +22,11 @@ func TestDefaulting(t *testing.T) {
 				Language: "test",
 			},
 			defaults: CustomDefaults{
-				Build:              optional.Some("build"),
-				DevModeBuild:       optional.Some("devmodebuild"),
-				BuildLock:          optional.Some("customdefaultlock"),
-				DeployDir:          "deploydir",
-				GeneratedSchemaDir: optional.Some("generatedschemadir"),
-				Watch:              []string{"a", "b", "c"},
+				Build:        optional.Some("build"),
+				DevModeBuild: optional.Some("devmodebuild"),
+				BuildLock:    optional.Some("customdefaultlock"),
+				DeployDir:    "deploydir",
+				Watch:        []string{"a", "b", "c"},
 			},
 			expected: ModuleConfig{
 				Realm:        "home",
@@ -57,11 +56,10 @@ func TestDefaulting(t *testing.T) {
 				},
 			},
 			defaults: CustomDefaults{
-				Build:              optional.Some("build"),
-				DevModeBuild:       optional.Some("devmodebuild"),
-				DeployDir:          "deploydir",
-				GeneratedSchemaDir: optional.Some("generatedschemadir"),
-				Watch:              []string{"a", "b", "c"},
+				Build:        optional.Some("build"),
+				DevModeBuild: optional.Some("devmodebuild"),
+				DeployDir:    "deploydir",
+				Watch:        []string{"a", "b", "c"},
 			},
 			expected: ModuleConfig{
 				Realm:        "home",

jvm-runtime/plugin/common/java_plugin_test.go

@@ -30,10 +30,9 @@ func TestJavaConfigDefaults(t *testing.T) {
 			language: "kotlin",
 			dir:      "testdata/kotlin/echo",
 			expected: moduleconfig.CustomDefaults{
-				Build:              optional.Some("mvn -B clean package"),
-				DevModeBuild:       optional.Some("mvn clean quarkus:dev"),
-				DeployDir:          "target",
-				GeneratedSchemaDir: optional.Some("src/main/ftl-module-schema"),
+				Build:        optional.Some("mvn -B clean package"),
+				DevModeBuild: optional.Some("mvn clean quarkus:dev"),
+				DeployDir:    "target",
 				LanguageConfig: map[string]any{
 					"build-tool": "maven",
 				},
@@ -50,10 +49,9 @@ func TestJavaConfigDefaults(t *testing.T) {
 			language: "kotlin",
 			dir:      "testdata/kotlin/external",
 			expected: moduleconfig.CustomDefaults{
-				Build:              optional.Some("mvn -B clean package"),
-				DevModeBuild:       optional.Some("mvn clean quarkus:dev"),
-				DeployDir:          "target",
-				GeneratedSchemaDir: optional.Some("src/main/ftl-module-schema"),
+				Build:        optional.Some("mvn -B clean package"),
+				DevModeBuild: optional.Some("mvn clean quarkus:dev"),
+				DeployDir:    "target",
 				LanguageConfig: map[string]any{
 					"build-tool": "maven",
 				},

jvm-runtime/plugin/common/jvmcommon.go

@@ -148,6 +148,19 @@ func (s *Service) GenerateStubs(ctx context.Context, req *connect.Request[langpb
 }
 
 func (s *Service) SyncStubReferences(ctx context.Context, req *connect.Request[langpb.SyncStubReferencesRequest]) (*connect.Response[langpb.SyncStubReferencesResponse], error) {
+
+	sch, err := schema.FromProto(req.Msg.Schema)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse schema from proto: %w", err)
+	}
+	config := langpb.ModuleConfigFromProto(req.Msg.ModuleConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse module config from proto: %w", err)
+	}
+	err = s.writeGenericSchemaFiles(ctx, sch, config)
+	if err != nil {
+		return nil, err
+	}
 	return connect.NewResponse(&langpb.SyncStubReferencesResponse{}), nil
 }
 
@@ -165,14 +178,20 @@ func (s *Service) Build(ctx context.Context, req *connect.Request[langpb.BuildRe
 	if err != nil {
 		return err
 	}
-	err = s.writeGenericSchemaFiles(ctx, buildCtx)
+	err = s.writeGenericSchemaFiles(ctx, buildCtx.Schema, buildCtx.Config)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to write generic schema files: %w", err)
 	}
 	if req.Msg.RebuildAutomatically {
 		return s.runDevMode(ctx, req, buildCtx, stream)
 	}
 
+	if s.acceptsContextUpdates.Load() {
+		// Already running in dev mode, we don't need to rebuild
+		s.updatesTopic.Publish(buildContextUpdatedEvent{buildCtx: buildCtx})
+		return nil
+	}
+
 	// Initial build
 	if err := buildAndSend(ctx, stream, buildCtx, false); err != nil {
 		return err
@@ -522,10 +541,6 @@ func (s *Service) BuildContextUpdated(ctx context.Context, req *connect.Request[
 	if err != nil {
 		return nil, err
 	}
-	err = s.writeGenericSchemaFiles(ctx, buildCtx)
-	if err != nil {
-		return nil, err
-	}
 
 	s.updatesTopic.Publish(buildContextUpdatedEvent{
 		buildCtx: buildCtx,
@@ -585,10 +600,9 @@ func loadJavaConfig(languageConfig any, language string) (JavaConfig, error) {
 
 func (s *Service) ModuleConfigDefaults(ctx context.Context, req *connect.Request[langpb.ModuleConfigDefaultsRequest]) (*connect.Response[langpb.ModuleConfigDefaultsResponse], error) {
 	defaults := langpb.ModuleConfigDefaultsResponse{
-		GeneratedSchemaDir: ptr("src/main/ftl-module-schema"),
-		LanguageConfig:     &structpb.Struct{Fields: map[string]*structpb.Value{}},
-		Watch:              []string{"pom.xml", "src/**", "build/generated", "target/generated-sources"},
-		SqlMigrationDir:    "src/main/db",
+		LanguageConfig:  &structpb.Struct{Fields: map[string]*structpb.Value{}},
+		Watch:           []string{"pom.xml", "src/**", "build/generated", "target/generated-sources"},
+		SqlMigrationDir: "src/main/db",
 	}
 	dir := req.Msg.Dir
 	pom := filepath.Join(dir, "pom.xml")
@@ -803,17 +817,21 @@ func ptr(s string) *string {
 	return &s
 }
 
-func (s *Service) writeGenericSchemaFiles(ctx context.Context, buildContext buildContext) error {
+func (s *Service) writeGenericSchemaFiles(ctx context.Context, v *schema.Schema, config moduleconfig.AbsModuleConfig) error {
 
-	modPath := filepath.Join(buildContext.Config.Dir, "src", "main", "ftl-module-schema")
+	logger := log.FromContext(ctx)
+	modPath := filepath.Join(config.Dir, "src", "main", "ftl-module-schema")
 	err := os.MkdirAll(modPath, 0750)
 	if err != nil {
 		return fmt.Errorf("failed to create directory %s: %w", modPath, err)
 	}
-	logger := log.FromContext(ctx)
 
-	for _, mod := range buildContext.Schema.Modules {
-		if mod.Name == buildContext.Config.Module {
+	for _, mod := range v.Modules {
+		if mod.Name == config.Module {
+			continue
+		}
+		deps := v.ModuleDependencies(mod.Name)
+		if deps[config.Module] != nil {
 			continue
 		}
 		data, err := schema.ModuleToBytes(mod)