docs/SCRIPTS_COMMAND.md

@@ -85,6 +85,23 @@ migrations/
 
 All files will be found and executed in Priority→Sequence order regardless of directory structure.
 
+## External File Embedding
+
+Script SQL can embed nearby text or binary files before execution using `-- @embed` directives:
+
+```sql
+-- @embed: path=assets/message.txt var=:message mode=text
+-- @embed: path=assets/photo.bin var=:payload mode=base64
+INSERT INTO assets (message, payload)
+VALUES (:message, decode(:payload, 'base64')::bytea);
+```
+
+- `path`: File path resolved relative to the SQL file containing the directive
+- `var`: Named placeholder to replace, such as `:message`
+- `mode`: `text` embeds an escaped SQL string literal; `base64` embeds a base64 string literal
+
+The directive comment is removed from the SQL, and every matching placeholder is replaced before the script is listed or executed.
+
 ## Commands
 
 ### relspec scripts list

pkg/assetloader/embed.go

@@ -0,0 +1,165 @@
+package assetloader
+
+import (
+	"encoding/base64"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+const ScriptSourcePathMetadataKey = "source_path"
+
+var (
+	embedDirectivePattern = regexp.MustCompile(`(?m)^\s*--\s*@embed:\s*(.+?)\s*$`)
+	embedAttrPattern      = regexp.MustCompile(`([a-zA-Z_][a-zA-Z0-9_]*)=("[^"]*"|'[^']*'|\S+)`)
+	embedVarPattern       = regexp.MustCompile(`^:[a-zA-Z_][a-zA-Z0-9_]*$`)
+)
+
+// ProcessEmbedDirectives expands SQL comments in the form:
+//
+//	-- @embed: path=... var=:... mode=text|base64
+//
+// Paths are resolved relative to sqlPath. Text mode embeds a quoted UTF-8 SQL
+// string literal. Base64 mode embeds a quoted base64 literal suitable for
+// decode(:var, 'base64').
+func ProcessEmbedDirectives(sqlPath, sql string) (string, error) {
+	directives := embedDirectivePattern.FindAllStringSubmatch(sql, -1)
+	if len(directives) == 0 {
+		return sql, nil
+	}
+
+	if sqlPath == "" {
+		return "", fmt.Errorf("sql path is required for embed directives")
+	}
+
+	result := embedDirectivePattern.ReplaceAllString(sql, "")
+	for i, directive := range directives {
+		literal, placeholder, err := embedDirectiveLiteral(sqlPath, directive[1], i+1)
+		if err != nil {
+			return "", err
+		}
+		if !embedPlaceholderPattern(placeholder).MatchString(result) {
+			return "", fmt.Errorf("%s embed directive %d: placeholder %s not found", sqlPath, i+1, placeholder)
+		}
+		result = replaceEmbedPlaceholder(result, placeholder, literal)
+	}
+
+	return result, nil
+}
+
+func embedDirectiveLiteral(sqlPath, raw string, directiveNumber int) (string, string, error) {
+	attrs, err := parseEmbedAttrs(raw)
+	if err != nil {
+		return "", "", fmt.Errorf("%s embed directive %d: %w", sqlPath, directiveNumber, err)
+	}
+
+	pathValue := attrs["path"]
+	varValue := attrs["var"]
+	modeValue := attrs["mode"]
+	if pathValue == "" {
+		return "", "", fmt.Errorf("%s embed directive %d: missing path", sqlPath, directiveNumber)
+	}
+	if !embedVarPattern.MatchString(varValue) {
+		return "", "", fmt.Errorf("%s embed directive %d: var must be a named placeholder like :asset", sqlPath, directiveNumber)
+	}
+	if modeValue != "text" && modeValue != "base64" {
+		return "", "", fmt.Errorf("%s embed directive %d: mode must be text or base64", sqlPath, directiveNumber)
+	}
+
+	resolved := filepath.Join(filepath.Dir(sqlPath), filepath.Clean(pathValue))
+	data, err := os.ReadFile(resolved)
+	if err != nil {
+		return "", "", fmt.Errorf("%s embed directive %d: reading %s: %w", sqlPath, directiveNumber, resolved, err)
+	}
+
+	switch modeValue {
+	case "text":
+		if !utf8.Valid(data) {
+			return "", "", fmt.Errorf("%s embed directive %d: %s is not valid UTF-8", sqlPath, directiveNumber, resolved)
+		}
+		literal, err := sqlStringLiteral(string(data))
+		if err != nil {
+			return "", "", fmt.Errorf("%s embed directive %d: %w", sqlPath, directiveNumber, err)
+		}
+		return literal, varValue, nil
+	case "base64":
+		literal, err := sqlStringLiteral(base64.StdEncoding.EncodeToString(data))
+		if err != nil {
+			return "", "", fmt.Errorf("%s embed directive %d: %w", sqlPath, directiveNumber, err)
+		}
+		return literal, varValue, nil
+	default:
+		return "", "", fmt.Errorf("%s embed directive %d: mode must be text or base64", sqlPath, directiveNumber)
+	}
+}
+
+func parseEmbedAttrs(raw string) (map[string]string, error) {
+	attrs := map[string]string{}
+	matches := embedAttrPattern.FindAllStringSubmatchIndex(raw, -1)
+	if len(matches) == 0 {
+		return nil, fmt.Errorf("expected path, var, and mode attributes")
+	}
+
+	lastEnd := 0
+	for _, match := range matches {
+		gap := strings.TrimSpace(raw[lastEnd:match[0]])
+		if gap != "" {
+			return nil, fmt.Errorf("invalid attribute syntax near %q", gap)
+		}
+
+		key := raw[match[2]:match[3]]
+		value := raw[match[4]:match[5]]
+		if _, exists := attrs[key]; exists {
+			return nil, fmt.Errorf("duplicate attribute %q", key)
+		}
+		unquoted, err := unquoteEmbedValue(value)
+		if err != nil {
+			return nil, fmt.Errorf("invalid %s value: %w", key, err)
+		}
+		attrs[key] = unquoted
+		lastEnd = match[1]
+	}
+	if tail := strings.TrimSpace(raw[lastEnd:]); tail != "" {
+		return nil, fmt.Errorf("invalid attribute syntax near %q", tail)
+	}
+
+	for key := range attrs {
+		if key != "path" && key != "var" && key != "mode" {
+			return nil, fmt.Errorf("unknown attribute %q", key)
+		}
+	}
+
+	return attrs, nil
+}
+
+func unquoteEmbedValue(value string) (string, error) {
+	if len(value) < 2 {
+		return value, nil
+	}
+	if value[0] == '"' {
+		return strconv.Unquote(value)
+	}
+	if value[0] == '\'' && value[len(value)-1] == '\'' {
+		return value[1 : len(value)-1], nil
+	}
+	return value, nil
+}
+
+func sqlStringLiteral(value string) (string, error) {
+	if strings.ContainsRune(value, '\x00') {
+		return "", fmt.Errorf("embedded text contains NUL byte")
+	}
+	return "'" + strings.ReplaceAll(value, "'", "''") + "'", nil
+}
+
+func replaceEmbedPlaceholder(sql, placeholder, literal string) string {
+	return embedPlaceholderPattern(placeholder).ReplaceAllString(sql, "${1}"+literal+"${2}")
+}
+
+func embedPlaceholderPattern(placeholder string) *regexp.Regexp {
+	return regexp.MustCompile(`(^|[^a-zA-Z0-9_:])` + regexp.QuoteMeta(placeholder) + `([^a-zA-Z0-9_]|$)`)
+}

pkg/assetloader/embed_test.go

@@ -0,0 +1,143 @@
+package assetloader
+
+import (
+	"encoding/base64"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestProcessEmbedDirectives_TextLiteralEscapesQuotes(t *testing.T) {
+	dir := t.TempDir()
+	sqlPath := filepath.Join(dir, "1_001_seed.sql")
+	if err := os.WriteFile(filepath.Join(dir, "body.txt"), []byte("Line 1\nIt's fine"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ProcessEmbedDirectives(sqlPath, `
+-- @embed: path=body.txt var=:body mode=text
+INSERT INTO notes (body) VALUES (:body);
+`)
+	if err != nil {
+		t.Fatalf("ProcessEmbedDirectives failed: %v", err)
+	}
+	if !strings.Contains(got, "VALUES ('Line 1\nIt''s fine');") {
+		t.Fatalf("embedded SQL did not contain escaped text literal:\n%s", got)
+	}
+	if strings.Contains(got, "VALUES (:body);") {
+		t.Fatalf("placeholder was not replaced:\n%s", got)
+	}
+}
+
+func TestProcessEmbedDirectives_Base64Literal(t *testing.T) {
+	dir := t.TempDir()
+	sqlPath := filepath.Join(dir, "1_001_seed.sql")
+	binary := []byte{0x00, 0xff, 0x10, 0x20}
+	if err := os.WriteFile(filepath.Join(dir, "blob.bin"), binary, 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ProcessEmbedDirectives(sqlPath, `
+-- @embed: path=blob.bin var=:payload mode=base64
+INSERT INTO files (payload) VALUES (decode(:payload, 'base64')::bytea);
+`)
+	if err != nil {
+		t.Fatalf("ProcessEmbedDirectives failed: %v", err)
+	}
+	want := "decode('" + base64.StdEncoding.EncodeToString(binary) + "', 'base64')::bytea"
+	if !strings.Contains(got, want) {
+		t.Fatalf("embedded SQL did not contain base64 literal %q:\n%s", want, got)
+	}
+}
+
+func TestProcessEmbedDirectives_RelativeToSQLFile(t *testing.T) {
+	root := t.TempDir()
+	sqlDir := filepath.Join(root, "nested", "seed")
+	if err := os.MkdirAll(filepath.Join(sqlDir, "assets"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	sqlPath := filepath.Join(sqlDir, "1_001_seed.sql")
+	if err := os.WriteFile(filepath.Join(sqlDir, "assets", "body.txt"), []byte("relative body"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ProcessEmbedDirectives(sqlPath, `
+-- @embed: path=assets/body.txt var=:body mode=text
+SELECT :body;
+`)
+	if err != nil {
+		t.Fatalf("ProcessEmbedDirectives failed: %v", err)
+	}
+	if !strings.Contains(got, "SELECT 'relative body';") {
+		t.Fatalf("path was not resolved relative to SQL file:\n%s", got)
+	}
+}
+
+func TestProcessEmbedDirectives_InvalidDirectiveAndFiles(t *testing.T) {
+	dir := t.TempDir()
+	sqlPath := filepath.Join(dir, "1_001_seed.sql")
+	if err := os.WriteFile(filepath.Join(dir, "body.txt"), []byte("ok"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "binary.txt"), []byte{0xff, 0xfe}, 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	tests := []struct {
+		name string
+		sql  string
+	}{
+		{
+			name: "missing mode",
+			sql:  "-- @embed: path=body.txt var=:body\nSELECT :body;",
+		},
+		{
+			name: "invalid var",
+			sql:  "-- @embed: path=body.txt var=body mode=text\nSELECT :body;",
+		},
+		{
+			name: "missing file",
+			sql:  "-- @embed: path=missing.txt var=:body mode=text\nSELECT :body;",
+		},
+		{
+			name: "invalid utf8 text",
+			sql:  "-- @embed: path=binary.txt var=:body mode=text\nSELECT :body;",
+		},
+		{
+			name: "placeholder not found",
+			sql:  "-- @embed: path=body.txt var=:body mode=text\nSELECT 1;",
+		},
+		{
+			name: "unknown attribute",
+			sql:  "-- @embed: path=body.txt var=:body mode=text extra=yes\nSELECT :body;",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if _, err := ProcessEmbedDirectives(sqlPath, tt.sql); err == nil {
+				t.Fatal("expected error, got nil")
+			}
+		})
+	}
+}
+
+func TestProcessEmbedDirectives_DoesNotReplacePlaceholderPrefix(t *testing.T) {
+	dir := t.TempDir()
+	sqlPath := filepath.Join(dir, "1_001_seed.sql")
+	if err := os.WriteFile(filepath.Join(dir, "body.txt"), []byte("ok"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ProcessEmbedDirectives(sqlPath, `
+-- @embed: path=body.txt var=:body mode=text
+SELECT :body, :body_extra;
+`)
+	if err != nil {
+		t.Fatalf("ProcessEmbedDirectives failed: %v", err)
+	}
+	if !strings.Contains(got, "SELECT 'ok', :body_extra;") {
+		t.Fatalf("placeholder boundary was not respected:\n%s", got)
+	}
+}

pkg/models/models.go

@@ -360,6 +360,7 @@ type Script struct {
 	Priority    int            `json:"priority,omitempty" yaml:"priority,omitempty" xml:"priority,omitempty"`
 	Sequence    uint           `json:"sequence,omitempty" yaml:"sequence,omitempty" xml:"sequence,omitempty"`
 	GUID        string         `json:"guid" yaml:"guid" xml:"guid"`
+	Metadata    map[string]any `json:"metadata,omitempty" yaml:"metadata,omitempty" xml:"-"`
 }
 
 // SQLName returns the script name in lowercase for SQL compatibility.
@@ -468,6 +469,7 @@ func InitScript(name string) *Script {
 	return &Script{
 		Name:     name,
 		RunAfter: make([]string, 0),
+		Metadata: make(map[string]any),
 		GUID:     uuid.New().String(),
 	}
 }

pkg/readers/sqldir/README.md

@@ -45,6 +45,21 @@ migrations/
 - `1_001_test.txt` - Wrong extension
 - `readme.md` - Not a SQL file
 
+## External File Embedding
+
+SQL files can include external files with `-- @embed` directives. File paths are resolved relative to the SQL file being read.
+
+```sql
+-- @embed: path=assets/message.txt var=:message mode=text
+-- @embed: path=assets/payload.bin var=:payload mode=base64
+INSERT INTO assets (message, payload)
+VALUES (:message, decode(:payload, 'base64')::bytea);
+```
+
+- `mode=text` reads UTF-8 text and replaces the placeholder with an escaped SQL string literal.
+- `mode=base64` reads any bytes and replaces the placeholder with a base64 SQL string literal.
+- The placeholder must be named, for example `:message`, and must appear in the SQL body.
+
 ## Usage
 
 ### Basic Usage

pkg/readers/sqldir/reader.go

@@ -7,6 +7,7 @@ import (
 	"regexp"
 	"strconv"
 
+	"git.warky.dev/wdevs/relspecgo/pkg/assetloader"
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/readers"
 )
@@ -151,6 +152,10 @@ func (r *Reader) readScripts() ([]*models.Script, error) {
 		if err != nil {
 			return fmt.Errorf("failed to read file %s: %w", path, err)
 		}
+		sql, err := assetloader.ProcessEmbedDirectives(path, string(content))
+		if err != nil {
+			return err
+		}
 
 		// Get relative path from base directory
 		relPath, err := filepath.Rel(r.options.FilePath, path)
@@ -161,9 +166,10 @@ func (r *Reader) readScripts() ([]*models.Script, error) {
 		// Create Script model
 		script := models.InitScript(name)
 		script.Description = fmt.Sprintf("SQL script from %s", relPath)
-		script.SQL = string(content)
+		script.SQL = sql
 		script.Priority = priority
 		script.Sequence = uint(sequence)
+		script.Metadata[assetloader.ScriptSourcePathMetadataKey] = path
 
 		scripts = append(scripts, script)
 

pkg/readers/sqldir/reader_test.go

@@ -1,8 +1,10 @@
 package sqldir
 
 import (
+	"encoding/base64"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/readers"
@@ -435,3 +437,61 @@ func TestReader_SkipSymlinks(t *testing.T) {
 		t.Error("Symlink script should have been skipped but was found")
 	}
 }
+
+func TestReader_EmbedDirectives(t *testing.T) {
+	tempDir := t.TempDir()
+	assetDir := filepath.Join(tempDir, "assets")
+	if err := os.MkdirAll(assetDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(assetDir, "message.txt"), []byte("Reader's text"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	binary := []byte{0x00, 0x01, 0xfe, 0xff}
+	if err := os.WriteFile(filepath.Join(assetDir, "payload.bin"), binary, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	sql := `
+-- @embed: path=assets/message.txt var=:message mode=text
+-- @embed: path=assets/payload.bin var=:payload mode=base64
+INSERT INTO assets (message, payload) VALUES (:message, decode(:payload, 'base64')::bytea);
+`
+	if err := os.WriteFile(filepath.Join(tempDir, "1_001_embed.sql"), []byte(sql), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	reader := NewReader(&readers.ReaderOptions{FilePath: tempDir})
+	db, err := reader.ReadDatabase()
+	if err != nil {
+		t.Fatalf("ReadDatabase failed: %v", err)
+	}
+	if len(db.Schemas[0].Scripts) != 1 {
+		t.Fatalf("expected 1 script, got %d", len(db.Schemas[0].Scripts))
+	}
+
+	got := db.Schemas[0].Scripts[0].SQL
+	if !strings.Contains(got, "'Reader''s text'") {
+		t.Fatalf("text asset was not embedded as an escaped SQL literal:\n%s", got)
+	}
+	wantBase64 := "decode('" + base64.StdEncoding.EncodeToString(binary) + "', 'base64')::bytea"
+	if !strings.Contains(got, wantBase64) {
+		t.Fatalf("binary asset was not embedded as a base64 SQL literal:\n%s", got)
+	}
+}
+
+func TestReader_EmbedDirectiveErrors(t *testing.T) {
+	tempDir := t.TempDir()
+	sql := "-- @embed: path=missing.txt var=:message mode=text\nSELECT :message;"
+	if err := os.WriteFile(filepath.Join(tempDir, "1_001_embed.sql"), []byte(sql), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	reader := NewReader(&readers.ReaderOptions{FilePath: tempDir})
+	_, err := reader.ReadDatabase()
+	if err == nil {
+		t.Fatal("expected embed error, got nil")
+	}
+	if !strings.Contains(err.Error(), "missing.txt") {
+		t.Fatalf("expected missing file in error, got %v", err)
+	}
+}

pkg/writers/sqlexec/writer.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/jackc/pgx/v5"
 
+	"git.warky.dev/wdevs/relspecgo/pkg/assetloader"
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 	"git.warky.dev/wdevs/relspecgo/pkg/writers"
@@ -138,7 +139,28 @@ func (w *Writer) executeScripts(ctx context.Context, conn *pgx.Conn, scripts []*
 			script.Name, script.Priority, script.Sequence)
 
 		// Execute the SQL script
-		_, err := conn.Exec(ctx, script.SQL)
+		sql, err := processEmbedDirectives(script)
+		if err != nil {
+			if ignoreErrors {
+				fmt.Printf("⚠ Error preparing %s: %v (continuing due to --ignore-errors)\n", script.Name, err)
+				failedScripts = append(failedScripts, struct {
+					name     string
+					priority int
+					sequence uint
+					err      error
+				}{
+					name:     script.Name,
+					priority: script.Priority,
+					sequence: script.Sequence,
+					err:      err,
+				})
+				continue
+			}
+			return fmt.Errorf("script %s (Priority=%d, Sequence=%d): %w",
+				script.Name, script.Priority, script.Sequence, err)
+		}
+
+		_, err = conn.Exec(ctx, sql)
 		if err != nil {
 			if ignoreErrors {
 				fmt.Printf("⚠ Error executing %s: %v (continuing due to --ignore-errors)\n", script.Name, err)
@@ -179,3 +201,11 @@ func (w *Writer) executeScripts(ctx context.Context, conn *pgx.Conn, scripts []*
 
 	return nil
 }
+
+func processEmbedDirectives(script *models.Script) (string, error) {
+	sqlPath, _ := script.Metadata[assetloader.ScriptSourcePathMetadataKey].(string)
+	if sqlPath == "" {
+		return script.SQL, nil
+	}
+	return assetloader.ProcessEmbedDirectives(sqlPath, script.SQL)
+}

pkg/writers/sqlexec/writer_test.go

@@ -1,8 +1,12 @@
 package sqlexec
 
 import (
+	"os"
+	"path/filepath"
+	"strings"
 	"testing"
 
+	"git.warky.dev/wdevs/relspecgo/pkg/assetloader"
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/writers"
 )
@@ -216,3 +220,36 @@ func TestWriter_WriteSchema_EmptyScripts(t *testing.T) {
 //     // Verify results
 //     // Cleanup
 // }
+
+func TestProcessEmbedDirectives_UsesScriptSourcePath(t *testing.T) {
+	dir := t.TempDir()
+	sqlPath := filepath.Join(dir, "1_001_seed.sql")
+	if err := os.WriteFile(filepath.Join(dir, "body.txt"), []byte("writer text"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	script := models.InitScript("seed")
+	script.SQL = "-- @embed: path=body.txt var=:body mode=text\nSELECT :body;"
+	script.Metadata[assetloader.ScriptSourcePathMetadataKey] = sqlPath
+
+	got, err := processEmbedDirectives(script)
+	if err != nil {
+		t.Fatalf("processEmbedDirectives failed: %v", err)
+	}
+	if !strings.Contains(got, "SELECT 'writer text';") {
+		t.Fatalf("script embed directive was not processed:\n%s", got)
+	}
+}
+
+func TestProcessEmbedDirectives_NoSourcePathLeavesSQLUnchanged(t *testing.T) {
+	script := models.InitScript("seed")
+	script.SQL = "-- @embed: path=missing.txt var=:body mode=text\nSELECT :body;"
+
+	got, err := processEmbedDirectives(script)
+	if err != nil {
+		t.Fatalf("processEmbedDirectives failed: %v", err)
+	}
+	if got != script.SQL {
+		t.Fatalf("expected unchanged SQL without source path, got:\n%s", got)
+	}
+}