Deterministic code generation for platform

internal/asset/files.go

@@ -5,6 +5,7 @@ import (
 	"github.com/viant/afs"
 	"github.com/viant/afs/file"
 	"github.com/viant/afs/url"
+	"go/format"
 	"strings"
 )
 
@@ -36,5 +37,12 @@ func (f Files) uploadContent(ctx context.Context, fs afs.Service, URL string, co
 	if ok, _ := fs.Exists(ctx, baseURL); !ok {
 		_ = fs.Create(ctx, baseURL, file.DefaultDirOsMode, true)
 	}
+	// gofmt generated Go files so their layout is stable across regenerations.
+	// Non-Go files and not-yet-valid Go are written through unchanged.
+	if strings.HasSuffix(URL, ".go") {
+		if formatted, err := format.Source([]byte(content)); err == nil {
+			content = string(formatted)
+		}
+	}
 	return fs.Upload(ctx, URL, file.DefaultFileOsMode, strings.NewReader(content))
 }

repository/codegen.go

@@ -13,6 +13,7 @@ import (
 	"github.com/viant/tagly/format/text"
 	"github.com/viant/toolbox/data"
 	"github.com/viant/xreflect"
+	"go/format"
 	"path"
 	"reflect"
 	"strconv"
@@ -198,6 +199,12 @@ func (c *Component) GenerateOutputCode(ctx context.Context, withDefineComponent,
 
 	result := builder.String()
 	result = c.View.Resource().ReverseSubstitutes(result)
+	// Normalize the generated source with gofmt so appended snippets (e.g. the
+	// EmbedFS method) are properly indented and the file ends with a newline.
+	// Fall back to the unformatted source if it is not yet valid Go.
+	if formatted, formatErr := format.Source([]byte(result)); formatErr == nil {
+		result = string(formatted)
+	}
 	return result
 }
 

repository/path/service.go

@@ -13,6 +13,7 @@ import (
 	"github.com/viant/datly/repository/version"
 	"gopkg.in/yaml.v3"
 	"path"
+	"sort"
 	"strings"
 	"sync"
 	"time"
@@ -151,6 +152,11 @@ func (s *Service) createPathFiles(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
+	// Sort candidates by URL so paths.yaml is written in a deterministic
+	// order regardless of the underlying filesystem listing order.
+	sort.Slice(candidates, func(i, j int) bool {
+		return candidates[i].URL() < candidates[j].URL()
+	})
 	rootPath := url.Path(s.URL)
 	for _, candidate := range candidates {
 		if candidate.IsDir() {

repository/shape/column/detector.go

@@ -6,6 +6,7 @@ import (
 	"reflect"
 	"strings"
 
+	"github.com/viant/datly/shared"
 	"github.com/viant/datly/view"
 	viewcolumn "github.com/viant/datly/view/column"
 	"github.com/viant/datly/view/state"
@@ -110,6 +111,9 @@ func discoverySQL(aView *view.View, resource *view.Resource) string {
 		}
 		return cleaned
 	}
+	// A view whose SQL is a derived table is wrapped in ( ... ); the balanced
+	// pair confuses the falsifier's parser, so trim it before falsifying.
+	cleaned = strings.TrimSpace(shared.TrimPair(cleaned, '(', ')'))
 	if falsified, ok := falsifyQuery(cleaned); ok {
 		return falsified
 	}
@@ -473,6 +477,21 @@ func needsDiscovery(aView *view.View) bool {
 	return usesWildcard(aView)
 }
 
+// discoveryReplacementFor keeps a discovery query valid once a ${...} template
+// is removed. A predicate builder that opens a WHERE clause is replaced with a
+// tautology so any trailing AND still binds; any other builder is dropped; a
+// plain value expression becomes an empty string literal.
+func discoveryReplacementFor(expr string) string {
+	if !strings.Contains(expr, ".Build(") {
+		return "''"
+	}
+	lower := strings.ToLower(expr)
+	if strings.Contains(lower, `build("where")`) || strings.Contains(lower, `build('where')`) {
+		return " WHERE 1 = 1 "
+	}
+	return ""
+}
+
 // stripTemplateVariables removes velocity/velty template constructs from SQL
 // so it can be parsed and executed for column discovery.
 // Handles: $variable, ${expression}, #if...#end, #foreach...#end, #set(...)
@@ -508,8 +527,15 @@ func stripTemplateVariables(sql string) string {
 					}
 					j++
 				}
-				// Replace with empty string or placeholder
-				b.WriteString("''")
+				// Predicate builders emit SQL clauses (e.g. Build("WHERE")); replace
+				// them with a valid stand-in so the discovery query stays parseable.
+				// Plain value expressions fall back to an empty string literal.
+				exprEnd := j - 1
+				if exprEnd < i+2 {
+					// Unterminated "${" at end of input: no expression body.
+					exprEnd = i + 2
+				}
+				b.WriteString(discoveryReplacementFor(sql[i+2 : exprEnd]))
 				i = j
 				continue
 			}

repository/shape/column/strip_test.go

@@ -44,7 +44,7 @@ func TestStripTemplateVariables(t *testing.T) {
 		{
 			name:   "expression in braces",
 			input:  "SELECT * FROM VENDOR WHERE ${predicate.Build(\"AND\")}",
-			expect: "SELECT * FROM VENDOR WHERE ''",
+			expect: "SELECT * FROM VENDOR WHERE ",
 		},
 		{
 			name:   "if directive",
@@ -64,7 +64,7 @@ func TestStripTemplateVariables(t *testing.T) {
 		{
 			name:   "mixed templates and SQL",
 			input:  "SELECT vendor.*, products.* FROM (SELECT * FROM VENDOR t) vendor JOIN (SELECT * FROM PRODUCT t WHERE 1=1 ${predicate.Builder().CombineOr($predicate.FilterGroup(0, \"AND\")).Build(\"AND\")}) products ON products.VENDOR_ID = vendor.ID",
-			expect: "SELECT vendor.*, products.* FROM (SELECT * FROM VENDOR t) vendor JOIN (SELECT * FROM PRODUCT t WHERE 1=1 '') products ON products.VENDOR_ID = vendor.ID",
+			expect: "SELECT vendor.*, products.* FROM (SELECT * FROM VENDOR t) vendor JOIN (SELECT * FROM PRODUCT t WHERE 1=1 ) products ON products.VENDOR_ID = vendor.ID",
 		},
 		{
 			name:   "UNION ALL with templates",
@@ -94,7 +94,7 @@ func TestStripTemplateVariables(t *testing.T) {
 		{
 			name:   "complex predicate builder",
 			input:  "WHERE ${predicate.Builder().CombineOr($predicate.FilterGroup(0, \"AND\")).Build(\"AND\")}",
-			expect: "WHERE ''",
+			expect: "WHERE ",
 		},
 		{
 			name:   "dollar at end",
@@ -156,7 +156,7 @@ perf AS (
     FROM fact_performance p
     JOIN params prm ON TRUE
     WHERE p.event_date BETWEEN prm.start_date AND prm.end_date
-      ''
+
     GROUP BY 1
 )
 SELECT v.* FROM perf v ORDER BY v.agency_id`,

repository/shape/discoverysql/prepare.go

@@ -3,6 +3,7 @@ package discoverysql
 import (
 	"strings"
 
+	"github.com/viant/datly/shared"
 	"github.com/viant/sqlparser"
 	"github.com/viant/sqlparser/expr"
 	"github.com/viant/sqlparser/node"
@@ -22,12 +23,30 @@ func PrepareDiscoverySQL(sql string) (string, bool) {
 	if cleaned == "" || !strings.Contains(strings.ToLower(cleaned), "select") {
 		return cleaned, false
 	}
+	// A view whose SQL is a derived table is wrapped in ( ... ); the balanced
+	// pair confuses the falsifier's parser, so trim it before falsifying.
+	cleaned = strings.TrimSpace(shared.TrimPair(cleaned, '(', ')'))
 	if rewritten, ok := falsifyQuery(cleaned); ok {
 		return rewritten, true
 	}
 	return falsifyQueryText(cleaned)
 }
 
+// discoveryReplacementFor keeps a discovery query valid once a ${...} template
+// is removed. A predicate builder that opens a WHERE clause is replaced with a
+// tautology so any trailing AND still binds; any other builder is dropped; a
+// plain value expression becomes an empty string literal.
+func discoveryReplacementFor(expr string) string {
+	if !strings.Contains(expr, ".Build(") {
+		return "''"
+	}
+	lower := strings.ToLower(expr)
+	if strings.Contains(lower, `build("where")`) || strings.Contains(lower, `build('where')`) {
+		return " WHERE 1 = 1 "
+	}
+	return ""
+}
+
 func falsifyQuery(sql string) (string, bool) {
 	sql = strings.TrimSpace(sql)
 	if sql == "" {
@@ -573,7 +592,15 @@ func stripTemplateVariables(sql string) string {
 					}
 					j++
 				}
-				b.WriteString("''")
+				// Predicate builders emit SQL clauses (e.g. Build("WHERE")); replace
+				// them with a valid stand-in so the discovery query stays parseable.
+				// Plain value expressions fall back to an empty string literal.
+				exprEnd := j - 1
+				if exprEnd < i+2 {
+					// Unterminated "${" at end of input: no expression body.
+					exprEnd = i + 2
+				}
+				b.WriteString(discoveryReplacementFor(sql[i+2 : exprEnd]))
 				i = j
 				continue
 			}