feat: add database type to the schema (#1374)

fixes #1306

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

@@ -44,6 +44,7 @@ message Database {
   optional Position pos = 1;
   string name = 2;
   repeated string comments = 3;
+  string type = 4;
 }
 
 message Decl {

backend/schema/database.go

@@ -9,10 +9,13 @@ import (
 	schemapb "github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v1/schema"
 )
 
+const PostgresDatabaseType = "postgres"
+
 type Database struct {
 	Pos Position `parser:"" protobuf:"1,optional"`
 
 	Comments []string `parser:"@Comment*" protobuf:"3"`
+	Type     string   `parser:"@'postgres'" protobuf:"4"`
 	Name     string   `parser:"'database' @Ident" protobuf:"2"`
 }
 
@@ -26,14 +29,15 @@ func (d *Database) schemaChildren() []Node { return nil }
 func (d *Database) String() string {
 	w := &strings.Builder{}
 	fmt.Fprint(w, encodeComments(d.Comments))
-	fmt.Fprintf(w, "database %s", d.Name)
+	fmt.Fprintf(w, "%s database %s", d.Type, d.Name)
 	return w.String()
 }
 
 func (d *Database) ToProto() proto.Message {
 	return &schemapb.Database{
 		Pos:      posToProto(d.Pos),
 		Name:     d.Name,
+		Type:     d.Type,
 		Comments: d.Comments,
 	}
 }
@@ -45,5 +49,6 @@ func DatabaseFromProto(s *schemapb.Database) *Database {
 		Pos:      posFromProto(s.Pos),
 		Name:     s.Name,
 		Comments: s.Comments,
+		Type:     s.Type,
 	}
 }

backend/schema/schema_test.go

@@ -22,7 +22,7 @@ module todo {
   config configValue String
   secret secretValue String
 
-  database testdb
+  postgres database testdb
 
   data CreateRequest {
     name {String: String}? +alias json "rqn"
@@ -387,7 +387,7 @@ func TestParseModule(t *testing.T) {
 module todo {
   config configValue String
   secret secretValue String
-  database testdb
+  postgres database testdb
 
   data CreateRequest {
     name {String: String}? +alias json "rqn"
@@ -467,6 +467,7 @@ var testSchema = MustValidate(&Schema{
 				},
 				&Database{
 					Name: "testdb",
+					Type: "postgres",
 				},
 				&Data{
 					Name: "CreateRequest",

backend/schema/validate_test.go

@@ -233,8 +233,8 @@ func TestValidate(t *testing.T) {
 		{name: "DuplicateDatabases",
 			schema: `
 				module one {
-                                        database MY_DB
-                                        database MY_DB
+                                        postgres database MY_DB
+                                        postgres database MY_DB
 				}
 			`,
 			errs: []string{

go-runtime/compile/schema.go

@@ -33,12 +33,12 @@ var (
 		return mustLoadRef("builtin", "error").Type().Underlying().(*types.Interface) //nolint:forcetypeassert
 	})
 
-	ftlCallFuncPath     = "github.com/TBD54566975/ftl/go-runtime/ftl.Call"
-	ftlConfigFuncPath   = "github.com/TBD54566975/ftl/go-runtime/ftl.Config"
-	ftlSecretFuncPath   = "github.com/TBD54566975/ftl/go-runtime/ftl.Secret" //nolint:gosec
-	ftlDatabaseFuncPath = "github.com/TBD54566975/ftl/go-runtime/ftl.PostgresDatabase"
-	ftlUnitTypePath     = "github.com/TBD54566975/ftl/go-runtime/ftl.Unit"
-	aliasFieldTag       = "json"
+	ftlCallFuncPath       = "github.com/TBD54566975/ftl/go-runtime/ftl.Call"
+	ftlConfigFuncPath     = "github.com/TBD54566975/ftl/go-runtime/ftl.Config"
+	ftlSecretFuncPath     = "github.com/TBD54566975/ftl/go-runtime/ftl.Secret" //nolint:gosec
+	ftlPostgresDBFuncPath = "github.com/TBD54566975/ftl/go-runtime/ftl.PostgresDatabase"
+	ftlUnitTypePath       = "github.com/TBD54566975/ftl/go-runtime/ftl.Unit"
+	aliasFieldTag         = "json"
 )
 
 // NativeNames is a map of top-level declarations to their native Go names.
@@ -182,8 +182,8 @@ func visitCallExpr(pctx *parseContext, node *ast.CallExpr) {
 	case ftlConfigFuncPath, ftlSecretFuncPath:
 		// Secret/config declaration: ftl.Config[<type>](<name>)
 		parseConfigDecl(pctx, node, fn)
-	case ftlDatabaseFuncPath:
-		parseDatabaseDecl(pctx, node)
+	case ftlPostgresDBFuncPath:
+		parseDatabaseDecl(pctx, node, schema.PostgresDatabaseType)
 	}
 }
 
@@ -281,7 +281,7 @@ func parseConfigDecl(pctx *parseContext, node *ast.CallExpr, fn *types.Func) {
 	pctx.module.Decls = append(pctx.module.Decls, decl)
 }
 
-func parseDatabaseDecl(pctx *parseContext, node *ast.CallExpr) {
+func parseDatabaseDecl(pctx *parseContext, node *ast.CallExpr, dbType string) {
 	var name string
 	if len(node.Args) == 1 {
 		if literal, ok := node.Args[0].(*ast.BasicLit); ok && literal.Kind == token.STRING {
@@ -311,6 +311,7 @@ func parseDatabaseDecl(pctx *parseContext, node *ast.CallExpr) {
 	decl := &schema.Database{
 		Pos:  goPosToSchemaPos(node.Pos()),
 		Name: name,
+		Type: dbType,
 	}
 	pctx.module.Decls = append(pctx.module.Decls, decl)
 }

go-runtime/compile/schema_test.go

@@ -50,7 +50,7 @@ func TestExtractModuleSchema(t *testing.T) {
   config configValue one.Config
   secret secretValue String
 
-  database testDb
+  postgres database testDb
 
   enum Color: String {
     Red = "Red"