private/model/api: Update SDK code generation for colliding field names (#96)

Ports aws/aws-sdk-go#1713 to the v2 SDK. Fixing the issue where API
field names could collide with SDK generated methods.

Fix #78

Author: jasdel

private/model/api/load.go

@@ -63,6 +63,8 @@ func (a *API) Setup() {
 	if !a.NoRenameToplevelShapes {
 		a.renameToplevelShapes()
 	}
+
+	a.renameCollidingFields()
 	a.updateTopLevelShapeReferences()
 	a.createInputOutputShapes()
 	a.customizationPasses()

private/model/api/passes.go

@@ -229,6 +229,49 @@ func (a *API) renameExportable() {
 	}
 }
 
+// renameCollidingFields will rename any fields that uses an SDK or Golang
+// specific name.
+func (a *API) renameCollidingFields() {
+	for _, v := range a.Shapes {
+		namesWithSet := map[string]struct{}{}
+		for k, field := range v.MemberRefs {
+			if strings.HasPrefix(k, "Set") {
+				namesWithSet[k] = struct{}{}
+			}
+
+			if collides(k) {
+				renameCollidingField(k, v, field)
+			}
+		}
+
+		// checks if any field names collide with setters.
+		for name := range namesWithSet {
+			if field, ok := v.MemberRefs["Set"+name]; ok {
+				renameCollidingField(name, v, field)
+			}
+		}
+	}
+}
+
+// collides will return true if it is a name used by the SDK or Golang.
+func collides(name string) bool {
+	switch name {
+	case "String",
+		"GoString",
+		"Validate":
+		return true
+	default:
+		return false
+	}
+}
+
+func renameCollidingField(name string, v *Shape, field *ShapeRef) {
+	newName := name + "_"
+	fmt.Printf("Shape %s's field %q renamed to %q\n", v.ShapeName, name, newName)
+	delete(v.MemberRefs, name)
+	v.MemberRefs[newName] = field
+}
+
 // createInputOutputShapes creates toplevel input/output shapes if they
 // have not been defined in the API. This normalizes all APIs to always
 // have an input and output structure in the signature.

private/model/api/passes_test.go

@@ -3,11 +3,12 @@
 package api
 
 import (
+	"reflect"
 	"testing"
 )
 
 func TestUniqueInputAndOutputs(t *testing.T) {
-	testCases := [][]struct {
+	cases := [][]struct {
 		expectedInput  string
 		expectedOutput string
 		operation      string
@@ -38,7 +39,7 @@ func TestUniqueInputAndOutputs(t *testing.T) {
 		},
 	}
 
-	for _, c := range testCases {
+	for _, c := range cases {
 		a := &API{
 			name:       "FooService",
 			Operations: map[string]*Operation{},
@@ -92,3 +93,45 @@ func TestUniqueInputAndOutputs(t *testing.T) {
 
 	}
 }
+
+func TestCollidingFields(t *testing.T) {
+	cases := []struct {
+		api      *API
+		expected []*Shapes
+	}{
+		{
+			&API{
+				name: "FooService",
+				Shapes: []*Shapes{
+					{
+						MemberRefs: map[string]*ShapeRef{
+							"String":   &ShapeRef{},
+							"GoString": &ShapeRef{},
+							"Validate": &ShapeRef{},
+							"Foo":      &ShapeRef{},
+							"SetFoo":   &ShapeRef{},
+						},
+					},
+				},
+			},
+			[]*Shapes{
+				{
+					MemberRefs: map[string]*ShapeRef{
+						"String_":   &ShapeRef{},
+						"GoString_": &ShapeRef{},
+						"Validate_": &ShapeRef{},
+						"Foo":       &ShapeRef{},
+						"SetFoo_":   &ShapeRef{},
+					},
+				},
+			},
+		},
+	}
+
+	for _, c := range testCases {
+		c.api.renameCollidingFields()
+		if !reflect.DeepEqual(c.api.Shapes, c.expected) {
+			t.Errorf("expected %v, but received %v", c.expected, c.api.Shapes)
+		}
+	}
+}