codegen: Generate valid enum names for symbols (#972)

Author: kyleconroy

internal/codegen/golang/result.go

@@ -34,12 +34,18 @@ func buildEnums(r *compiler.Result, settings config.CombinedSettings) []Enum {
 				Name:    StructName(enumName, settings),
 				Comment: enum.Comment,
 			}
-			for _, v := range enum.Vals {
+			seen := make(map[string]struct{}, len(enum.Vals))
+			for i, v := range enum.Vals {
+				value := EnumReplace(v)
+				if _, found := seen[value]; found || value == "" {
+					value = fmt.Sprintf("value_%d", i)
+				}
 				e.Constants = append(e.Constants, Constant{
-					Name:  StructName(enumName+"_"+EnumReplace(v), settings),
+					Name:  StructName(enumName+"_"+value, settings),
 					Value: v,
 					Type:  e.Name,
 				})
+				seen[value] = struct{}{}
 			}
 			enums = append(enums, e)
 		}

internal/endtoend/testdata/ddl_create_enum/mysql/go/models.go

@@ -1,3 +1,4 @@
 CREATE TABLE foo (
-    foobar ENUM ('foo-a', 'foo_b', 'foo:c', 'foo/d', 'foo@e', 'foo+f', 'foo!g') NOT NULL
+    foobar ENUM ('foo-a', 'foo_b', 'foo:c', 'foo/d', 'foo@e', 'foo+f', 'foo!g') NOT NULL,
+    digit  ENUM ('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '#', '*')    NOT NULL
 );

internal/endtoend/testdata/ddl_create_enum/mysql/go/query.sql.go

@@ -10,4 +10,19 @@ CREATE TYPE foobar AS ENUM (
     'foo!g'
 );
 
+CREATE TYPE "digit" AS ENUM (
+  '0',
+  '1',
+  '2',
+  '3',
+  '4',
+  '5',
+  '6',
+  '7',
+  '8',
+  '9',
+  '#',
+  '*'
+);
+
 CREATE TABLE foo (val foobar NOT NULL);