feat(templ): add support for --from-list flag and related tests

cmd/relspec/templ.go

@@ -15,6 +15,7 @@ var (
 	templSourceType      string
 	templSourcePath      string
 	templSourceConn      string
+	templFromList        []string
 	templTemplatePath    string
 	templOutputPath      string
 	templSchemaFilter    string
@@ -78,8 +79,9 @@ Examples:
 
 func init() {
 	templCmd.Flags().StringVar(&templSourceType, "from", "", "Source format (dbml, pgsql, json, etc.)")
-	templCmd.Flags().StringVar(&templSourcePath, "from-path", "", "Source file path (for file-based sources)")
+	templCmd.Flags().StringVar(&templSourcePath, "from-path", "", "Source file path (for file-based sources, mutually exclusive with --from-list)")
 	templCmd.Flags().StringVar(&templSourceConn, "from-conn", "", "Source connection string (for database sources)")
+	templCmd.Flags().StringSliceVar(&templFromList, "from-list", nil, "Comma-separated list of source file paths to read and merge (mutually exclusive with --from-path)")
 	templCmd.Flags().StringVar(&templTemplatePath, "template", "", "Template file path (required)")
 	templCmd.Flags().StringVar(&templOutputPath, "output", "", "Output path (file or directory, empty for stdout)")
 	templCmd.Flags().StringVar(&templSchemaFilter, "schema", "", "Filter to specific schema")
@@ -95,9 +97,20 @@ func runTempl(cmd *cobra.Command, args []string) error {
 	fmt.Fprintf(os.Stderr, "=== RelSpec Template Execution ===\n")
 	fmt.Fprintf(os.Stderr, "Started at: %s\n\n", getCurrentTimestamp())
 
+	// Validate mutually exclusive flags
+	if templSourcePath != "" && len(templFromList) > 0 {
+		return fmt.Errorf("--from-path and --from-list are mutually exclusive")
+	}
+
 	// Read database using the same function as convert
 	fmt.Fprintf(os.Stderr, "Reading from %s...\n", templSourceType)
-	db, err := readDatabaseForConvert(templSourceType, templSourcePath, templSourceConn)
+	var db *models.Database
+	var err error
+	if len(templFromList) > 0 {
+		db, err = readDatabaseListForConvert(templSourceType, templFromList)
+	} else {
+		db, err = readDatabaseForConvert(templSourceType, templSourcePath, templSourceConn)
+	}
 	if err != nil {
 		return fmt.Errorf("failed to read source: %w", err)
 	}

cmd/relspec/templ_from_list_test.go

@@ -0,0 +1,134 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// writeTestTemplate writes a minimal Go text template file.
+func writeTestTemplate(t *testing.T, path string) {
+	t.Helper()
+	content := []byte(`{{.Name}}`)
+	if err := os.WriteFile(path, content, 0644); err != nil {
+		t.Fatalf("failed to write template file %s: %v", path, err)
+	}
+}
+
+func TestRunTempl_FromListMutuallyExclusiveWithFromPath(t *testing.T) {
+	saved := saveTemplState()
+	defer restoreTemplState(saved)
+
+	dir := t.TempDir()
+	file := filepath.Join(dir, "schema.json")
+	tmpl := filepath.Join(dir, "tmpl.tmpl")
+	writeTestJSON(t, file, []string{"users"})
+	writeTestTemplate(t, tmpl)
+
+	templSourceType = "json"
+	templSourcePath = file
+	templFromList = []string{file}
+	templTemplatePath = tmpl
+	templOutputPath = ""
+	templMode = "database"
+	templFilenamePattern = "{{.Name}}.txt"
+
+	err := runTempl(nil, nil)
+	if err == nil {
+		t.Error("expected error when --from-path and --from-list are both set")
+	}
+}
+
+func TestRunTempl_FromListSingleFile(t *testing.T) {
+	saved := saveTemplState()
+	defer restoreTemplState(saved)
+
+	dir := t.TempDir()
+	file := filepath.Join(dir, "schema.json")
+	tmpl := filepath.Join(dir, "tmpl.tmpl")
+	outFile := filepath.Join(dir, "output.txt")
+	writeTestJSON(t, file, []string{"users"})
+	writeTestTemplate(t, tmpl)
+
+	templSourceType = "json"
+	templSourcePath = ""
+	templSourceConn = ""
+	templFromList = []string{file}
+	templTemplatePath = tmpl
+	templOutputPath = outFile
+	templSchemaFilter = ""
+	templMode = "database"
+	templFilenamePattern = "{{.Name}}.txt"
+
+	if err := runTempl(nil, nil); err != nil {
+		t.Fatalf("runTempl() error = %v", err)
+	}
+	if _, err := os.Stat(outFile); os.IsNotExist(err) {
+		t.Error("expected output file to be created")
+	}
+}
+
+func TestRunTempl_FromListMultipleFiles(t *testing.T) {
+	saved := saveTemplState()
+	defer restoreTemplState(saved)
+
+	dir := t.TempDir()
+	file1 := filepath.Join(dir, "users.json")
+	file2 := filepath.Join(dir, "posts.json")
+	tmpl := filepath.Join(dir, "tmpl.tmpl")
+	outFile := filepath.Join(dir, "output.txt")
+	writeTestJSON(t, file1, []string{"users"})
+	writeTestJSON(t, file2, []string{"posts"})
+	writeTestTemplate(t, tmpl)
+
+	templSourceType = "json"
+	templSourcePath = ""
+	templSourceConn = ""
+	templFromList = []string{file1, file2}
+	templTemplatePath = tmpl
+	templOutputPath = outFile
+	templSchemaFilter = ""
+	templMode = "database"
+	templFilenamePattern = "{{.Name}}.txt"
+
+	if err := runTempl(nil, nil); err != nil {
+		t.Fatalf("runTempl() error = %v", err)
+	}
+	if _, err := os.Stat(outFile); os.IsNotExist(err) {
+		t.Error("expected output file to be created")
+	}
+}
+
+func TestRunTempl_FromListPathWithSpaces(t *testing.T) {
+	saved := saveTemplState()
+	defer restoreTemplState(saved)
+
+	spacedDir := filepath.Join(t.TempDir(), "my schema files")
+	if err := os.MkdirAll(spacedDir, 0755); err != nil {
+		t.Fatal(err)
+	}
+	file1 := filepath.Join(spacedDir, "users schema.json")
+	file2 := filepath.Join(spacedDir, "posts schema.json")
+	tmpl := filepath.Join(spacedDir, "my template.tmpl")
+	outFile := filepath.Join(spacedDir, "output file.txt")
+	writeTestJSON(t, file1, []string{"users"})
+	writeTestJSON(t, file2, []string{"posts"})
+	writeTestTemplate(t, tmpl)
+
+	templSourceType = "json"
+	templSourcePath = ""
+	templSourceConn = ""
+	templFromList = []string{file1, file2}
+	templTemplatePath = tmpl
+	templOutputPath = outFile
+	templSchemaFilter = ""
+	templMode = "database"
+	templFilenamePattern = "{{.Name}}.txt"
+
+	if err := runTempl(nil, nil); err != nil {
+		t.Fatalf("runTempl() with spaced paths error = %v", err)
+	}
+	if _, err := os.Stat(outFile); os.IsNotExist(err) {
+		t.Error("expected output file to be created")
+	}
+}

cmd/relspec/testhelpers_test.go

@@ -110,6 +110,45 @@ func restoreConvertState(s convertState) {
 	convertFlattenSchema = s.flattenSchema
 }
 
+// templState captures and restores all templ global vars.
+type templState struct {
+	sourceType      string
+	sourcePath      string
+	sourceConn      string
+	fromList        []string
+	templatePath    string
+	outputPath      string
+	schemaFilter    string
+	mode            string
+	filenamePattern string
+}
+
+func saveTemplState() templState {
+	return templState{
+		sourceType:      templSourceType,
+		sourcePath:      templSourcePath,
+		sourceConn:      templSourceConn,
+		fromList:        templFromList,
+		templatePath:    templTemplatePath,
+		outputPath:      templOutputPath,
+		schemaFilter:    templSchemaFilter,
+		mode:            templMode,
+		filenamePattern: templFilenamePattern,
+	}
+}
+
+func restoreTemplState(s templState) {
+	templSourceType = s.sourceType
+	templSourcePath = s.sourcePath
+	templSourceConn = s.sourceConn
+	templFromList = s.fromList
+	templTemplatePath = s.templatePath
+	templOutputPath = s.outputPath
+	templSchemaFilter = s.schemaFilter
+	templMode = s.mode
+	templFilenamePattern = s.filenamePattern
+}
+
 // mergeState captures and restores all merge global vars.
 type mergeState struct {
 	targetType    string