sqldb: harden migration config consistency tests

Strengthen migration consistency coverage by checking the reverse
mapping from embedded SQL files to migrationConfig entries, deriving
previous schema state from slice order instead of Version, rejecting
schema version regressions, and asserting migration names match the
embedded SQL file stems.

Also fix the graph v2 migration config name to match the embedded
migration filename.

sqldb/migrations.go

@@ -93,7 +93,7 @@ var (
 			// user if necessary.
 		},
 		{
-			Name:          "000009_graph_v2_columns",
+			Name:          "000009_graph_v2",
 			Version:       11,
 			SchemaVersion: 9,
 		},

sqldb/migrations_dev_test.go

@@ -0,0 +1,52 @@
+//go:build test_db_postgres || test_db_sqlite || test_native_sql
+
+package sqldb
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestMigrationFilesAllRegistered verifies that every .up.sql file in the
+// embedded migrations filesystem has a corresponding entry in migrationConfig.
+// This test requires dev build tags so that any future dev-only migrations
+// added to migrationAdditions are visible — without them, such entries would
+// be absent and their SQL files would trigger false failures.
+func TestMigrationFilesAllRegistered(t *testing.T) {
+	t.Parallel()
+
+	migrations := GetMigrations()
+	require.NotEmpty(t, migrations)
+
+	// Collect all schema versions referenced by any entry in migrationConfig
+	// (including migrationAdditions, which is only populated under dev build
+	// tags).
+	registeredSchemaVersions := make(map[int]string)
+	for _, m := range migrations {
+		registeredSchemaVersions[m.SchemaVersion] = m.Name
+	}
+
+	// Read all .up.sql files from the embedded filesystem.
+	embeddedFiles, err := sqlSchemas.ReadDir("sqlc/migrations")
+	require.NoError(t, err)
+
+	for _, f := range embeddedFiles {
+		if f.IsDir() {
+			continue
+		}
+
+		var schemaVersion int
+		_, err := fmt.Sscanf(f.Name(), "%06d_", &schemaVersion)
+		require.NoError(t, err, "migration file %q has no valid "+
+			"numeric prefix", f.Name())
+
+		_, referenced := registeredSchemaVersions[schemaVersion]
+		require.True(t, referenced,
+			"SQL migration file %q (schema version %d) has no "+
+				"corresponding entry in migrationConfig — add "+
+				"an entry with SchemaVersion=%d",
+			f.Name(), schemaVersion, schemaVersion)
+	}
+}

sqldb/migrations_test.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"fmt"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/golang-migrate/migrate/v4"
@@ -667,7 +668,7 @@ func TestMigrationConfigConsistency(t *testing.T) {
 	seenVersions := make(map[int]string)
 	seenSchemaVersions := make(map[int]string)
 
-	for _, m := range migrations {
+	for i, m := range migrations {
 		// 1. Verify no duplicate global versions.
 		if existing, ok := seenVersions[m.Version]; ok {
 			t.Fatalf("duplicate global version %d: %q and %q",
@@ -680,20 +681,29 @@ func TestMigrationConfigConsistency(t *testing.T) {
 		//    and no two config entries claim the same schema version
 		//    with different file prefixes.
 		prevSchema := 0
-		if m.Version > 1 {
-			prevSchema = migrations[m.Version-2].SchemaVersion
+		if i > 0 {
+			prevSchema = migrations[i-1].SchemaVersion
 		}
 
+		require.GreaterOrEqual(t, m.SchemaVersion, prevSchema,
+			"migration %q regresses schema version from %d to %d",
+			m.Name, prevSchema, m.SchemaVersion)
+
 		// A migration advances the schema if its SchemaVersion is
 		// higher than the previous migration's SchemaVersion.
 		if m.SchemaVersion > prevSchema {
-			_, hasFile := fileSchemaVersions[m.SchemaVersion]
+			fileName, hasFile := fileSchemaVersions[m.SchemaVersion]
 			require.True(t, hasFile,
 				"migration %q (version %d) declares "+
 					"SchemaVersion=%d but no %06d_*.up.sql"+
 					" file exists in the embedded FS",
 				m.Name, m.Version, m.SchemaVersion,
 				m.SchemaVersion)
+			require.Equal(t, strings.TrimSuffix(fileName, ".up.sql"),
+				m.Name, "migration %q (version %d) has "+
+					"SchemaVersion=%d but its name does not "+
+					"match embedded file %q",
+				m.Name, m.Version, m.SchemaVersion, fileName)
 
 			if existing, ok := seenSchemaVersions[m.SchemaVersion]; ok {
 				t.Fatalf("duplicate schema version %d: "+