fix(dbfixture): directly call funcs bypassing template eval

dbfixture/fixture.go

@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"strings"
 	"text/template"
+	"text/template/parse"
 	"time"
 
 	"gopkg.in/yaml.v3"
@@ -249,13 +250,11 @@ func (f *Fixture) decodeField(strct reflect.Value, field *schema.Field, value *y
 	}
 
 	if tplRE.MatchString(value.Value) {
-		str, err := f.eval(value.Value)
+		src, err := f.eval(value.Value)
 		if err != nil {
 			return err
 		}
-		if str != value.Value {
-			return field.ScanValue(strct, str)
-		}
+		return field.ScanValue(strct, src)
 	}
 
 	if v, ok := iface.(yaml.Unmarshaler); ok {
@@ -310,21 +309,100 @@ func (f *Fixture) truncateTable(ctx context.Context, table *schema.Table) error
 	return nil
 }
 
-func (f *Fixture) eval(templ string) (string, error) {
+func (f *Fixture) eval(templ string) (interface{}, error) {
+	if v, ok := f.evalFuncCall(templ); ok {
+		return v, nil
+	}
+
 	tpl, err := template.New("").Funcs(f.funcMap).Parse(templ)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	var buf bytes.Buffer
 
 	if err := tpl.Execute(&buf, f.modelRows); err != nil {
-		return "", err
+		return nil, err
 	}
 
 	return buf.String(), nil
 }
 
+func (f *Fixture) evalFuncCall(templ string) (interface{}, bool) {
+	tree, err := parse.Parse("", templ, "{{", "}}", f.funcMap)
+	if err != nil {
+		return nil, false
+	}
+
+	root := tree[""].Root
+	if len(root.Nodes) != 1 {
+		return nil, false
+	}
+
+	action, ok := root.Nodes[0].(*parse.ActionNode)
+	if !ok {
+		return nil, false
+	}
+
+	if len(action.Pipe.Cmds) != 1 {
+		return nil, false
+	}
+
+	args := action.Pipe.Cmds[0].Args
+	if len(args) == 0 {
+		return nil, false
+	}
+
+	funcName, ok := args[0].(*parse.IdentifierNode)
+	if !ok {
+		return nil, false
+	}
+
+	fn, ok := f.funcMap[funcName.Ident]
+	if !ok {
+		return nil, false
+	}
+
+	fnValue := reflect.ValueOf(fn)
+	fnType := fnValue.Type()
+	if fnType.NumOut() != 1 {
+		return nil, false
+	}
+
+	args = args[1:]
+	if len(args) != fnType.NumIn() {
+		return nil, false
+	}
+	argValues := make([]reflect.Value, len(args))
+
+	for i, node := range args {
+		switch node := node.(type) {
+		case *parse.StringNode:
+			argValues[i] = reflect.ValueOf(node.Text)
+		case *parse.NumberNode:
+			switch {
+			case node.IsInt:
+				argValues[i] = reflect.ValueOf(node.Int64)
+			case node.IsUint:
+				argValues[i] = reflect.ValueOf(node.Uint64)
+			case node.IsFloat:
+				argValues[i] = reflect.ValueOf(node.Float64)
+			case node.IsComplex:
+				argValues[i] = reflect.ValueOf(node.Complex128)
+			default:
+				argValues[i] = reflect.ValueOf(node.Text)
+			}
+		case *parse.BoolNode:
+			argValues[i] = reflect.ValueOf(node.True)
+		default:
+			return nil, false
+		}
+	}
+
+	out := fnValue.Call(argValues)
+	return out[0].Interface(), true
+}
+
 type fixtureData struct {
 	Model string `yaml:"model"`
 	Rows  []row  `yaml:"rows"`