feat: Change plugin signatures

api/generate.go

@@ -37,6 +37,13 @@ func Generate(cfg *config.Config, option ...Option) error {
 				cfg.Sources = append(cfg.Sources, s)
 			}
 		}
+		if inj, ok := p.(plugin.EarlySourcesInjector); ok {
+			s, err := inj.InjectSourcesEarly()
+			if err != nil {
+				return fmt.Errorf("%s: %w", p.Name(), err)
+			}
+			cfg.Sources = append(cfg.Sources, s...)
+		}
 	}
 
 	if err := cfg.LoadSchema(); err != nil {
@@ -49,6 +56,13 @@ func Generate(cfg *config.Config, option ...Option) error {
 				cfg.Sources = append(cfg.Sources, s)
 			}
 		}
+		if inj, ok := p.(plugin.LateSourcesInjector); ok {
+			s, err := inj.InjectSourcesLate(cfg.Schema)
+			if err != nil {
+				return fmt.Errorf("%s: %w", p.Name(), err)
+			}
+			cfg.Sources = append(cfg.Sources, s...)
+		}
 	}
 
 	// LoadSchema again now we have everything

plugin/federation/federation.go

@@ -66,8 +66,8 @@ func (f *federation) MutateConfig(cfg *config.Config) error {
 	return nil
 }
 
-func (f *federation) InjectSourceEarly() *ast.Source {
-	return &ast.Source{
+func (f *federation) InjectSourcesEarly() ([]*ast.Source, error) {
+	return []*ast.Source{{
 		Name: "federation/directives.graphql",
 		Input: `
 scalar _Any
@@ -80,12 +80,12 @@ directive @key(fields: _FieldSet!) repeatable on OBJECT | INTERFACE
 directive @extends on OBJECT | INTERFACE
 `,
 		BuiltIn: true,
-	}
+	}}, nil
 }
 
 // InjectSources creates a GraphQL Entity type with all
 // the fields that had the @key directive
-func (f *federation) InjectSourceLate(schema *ast.Schema) *ast.Source {
+func (f *federation) InjectSourcesLate(schema *ast.Schema) ([]*ast.Source, error) {
 	f.setEntities(schema)
 
 	var entities, resolvers, entityResolverInputDefinitions string
@@ -157,11 +157,11 @@ type Entity {
 }`
 	blocks = append(blocks, extendTypeQueryDef)
 
-	return &ast.Source{
+	return []*ast.Source{{
 		Name:    "federation/entity.graphql",
 		BuiltIn: true,
 		Input:   "\n" + strings.Join(blocks, "\n\n") + "\n",
-	}
+	}}, nil
 }
 
 // Entity represents a federated type

plugin/federation/federation_test.go

@@ -163,7 +163,9 @@ func load(t *testing.T, name string) (*federation, *config.Config) {
 	require.NoError(t, err)
 
 	f := &federation{}
-	cfg.Sources = append(cfg.Sources, f.InjectSourceEarly())
+	s, err := f.InjectSourcesEarly()
+	require.NoError(t, err)
+	cfg.Sources = append(cfg.Sources, s...)
 	require.NoError(t, cfg.LoadSchema())
 
 	if src := f.InjectSourceLate(cfg.Schema); src != nil {

plugin/plugin.go

@@ -21,11 +21,23 @@ type CodeGenerator interface {
 }
 
 // EarlySourceInjector is used to inject things that are required for user schema files to compile.
+// Deprecated: Use EarlySourcesInjector instead
 type EarlySourceInjector interface {
 	InjectSourceEarly() *ast.Source
 }
 
+// EarlySourcesInjector is used to inject things that are required for user schema files to compile.
+type EarlySourcesInjector interface {
+	InjectSourcesEarly() ([]*ast.Source, error)
+}
+
 // LateSourceInjector is used to inject more sources, after we have loaded the users schema.
+// Deprecated: Use LateSourcesInjector instead
 type LateSourceInjector interface {
 	InjectSourceLate(schema *ast.Schema) *ast.Source
 }
+
+// LateSourcesInjector is used to inject more sources, after we have loaded the users schema.
+type LateSourcesInjector interface {
+	InjectSourcesLate(schema *ast.Schema) ([]*ast.Source, error)
+}