fix(codegen): allow using x-go-type and x-go-type-skip-optional-pointer together

When using `x-go-type`, `GenerateGoSchema` returns early, meaning that
any extensions that are checked after this one are no-op.

This PR moves the code for `x-go-type-skip-optional-pointer` higher up,
so it can be used alongside `x-go-type`.

This corrects this piece of behaviour, and amends our generated code
examples to correctly apply `x-go-type-skip-optional-pointer` when using
an optional field, or inside an `AllOf`.

Author: Nivl

internal/test/issues/issue1957/issue1957.gen.go

@@ -27,32 +27,28 @@ func TestGeneratedCode(t *testing.T) {
 	})
 
 	t.Run("For a query parameter", func(t *testing.T) {
-		// TODO that this is NOT wanted behaviour, but it is our current behaviour
-		t.Run("An optional field with x-go-type-skip-optional-pointer should be a pointer", func(t *testing.T) {
+		t.Run("An optional field with x-go-type-skip-optional-pointer should be a non-pointer", func(t *testing.T) {
 
 			u := uuid.New()
 
 			theType := GetRootParams{
-				At: &u,
+				At: u,
 			}
 
-			require.NotNil(t, theType.At)
-			require.NotZero(t, *theType.At)
+			require.NotZero(t, theType.At)
 		})
 	})
 
 	t.Run("For a field with an AllOf", func(t *testing.T) {
-		// TODO that this is NOT wanted behaviour, but it is our current behaviour
-		t.Run("An optional field with x-go-type-skip-optional-pointer should be a pointer", func(t *testing.T) {
+		t.Run("An optional field with x-go-type-skip-optional-pointer should be a non-pointer", func(t *testing.T) {
 
 			u := uuid.New()
 
 			theType := TypeWithAllOf{
-				Id: &u,
+				Id: u,
 			}
 
-			require.NotNil(t, theType.Id)
-			require.NotZero(t, *theType.Id)
+			require.NotZero(t, theType.Id)
 		})
 	})
 }

internal/test/issues/issue1957/issue1957_test.go

@@ -289,6 +289,16 @@ func GenerateGoSchema(sref *openapi3.SchemaRef, path []string) (Schema, error) {
 		return mergedSchema, nil
 	}
 
+	// Check x-go-type-skip-optional-pointer, which will override if the type
+	// should be a pointer or not when the field is optional.
+	if extension, ok := schema.Extensions[extPropGoTypeSkipOptionalPointer]; ok {
+		skipOptionalPointer, err := extParsePropGoTypeSkipOptionalPointer(extension)
+		if err != nil {
+			return outSchema, fmt.Errorf("invalid value for %q: %w", extPropGoTypeSkipOptionalPointer, err)
+		}
+		outSchema.SkipOptionalPointer = skipOptionalPointer
+	}
+
 	// Check x-go-type, which will completely override the definition of this
 	// schema with the provided type.
 	if extension, ok := schema.Extensions[extPropGoType]; ok {
@@ -302,16 +312,6 @@ func GenerateGoSchema(sref *openapi3.SchemaRef, path []string) (Schema, error) {
 		return outSchema, nil
 	}
 
-	// Check x-go-type-skip-optional-pointer, which will override if the type
-	// should be a pointer or not when the field is optional.
-	if extension, ok := schema.Extensions[extPropGoTypeSkipOptionalPointer]; ok {
-		skipOptionalPointer, err := extParsePropGoTypeSkipOptionalPointer(extension)
-		if err != nil {
-			return outSchema, fmt.Errorf("invalid value for %q: %w", extPropGoTypeSkipOptionalPointer, err)
-		}
-		outSchema.SkipOptionalPointer = skipOptionalPointer
-	}
-
 	// Schema type and format, eg. string / binary
 	t := schema.Type
 	// Handle objects and empty schemas first as a special case