Teach struct types to render themselves to go code. (#348)

Rather than including all go rendering logic in a large writeTypes
function, this patch teaches go structs that represent types and fields
to render themselves with Render() methods. Then we can write and test
each Render method independently, and combine them in writeTypes.

Part of #350.

Author: jmcarp

internal/generate/paths.go

@@ -315,27 +315,27 @@ func writeTpl(f *os.File, config methodTemplate) error {
 	var err error
 
 	if config.IsListAll {
-		t, err = template.ParseFiles("./templates/listall_method.tpl", "./templates/description.tpl")
+		t, err = template.ParseFiles("./templates/listall_method.go.tpl", "./templates/description.go.tpl")
 		if err != nil {
 			return err
 		}
 	} else if config.ResponseType == "" && config.HasBody {
-		t, err = template.ParseFiles("./templates/no_resptype_body_method.tpl", "./templates/description.tpl")
+		t, err = template.ParseFiles("./templates/no_resptype_body_method.go.tpl", "./templates/description.go.tpl")
 		if err != nil {
 			return err
 		}
 	} else if config.ResponseType == "" {
-		t, err = template.ParseFiles("./templates/no_resptype_method.tpl", "./templates/description.tpl")
+		t, err = template.ParseFiles("./templates/no_resptype_method.go.tpl", "./templates/description.go.tpl")
 		if err != nil {
 			return err
 		}
 	} else if config.HasBody {
-		t, err = template.ParseFiles("./templates/resptype_body_method.tpl", "./templates/description.tpl")
+		t, err = template.ParseFiles("./templates/resptype_body_method.go.tpl", "./templates/description.go.tpl")
 		if err != nil {
 			return err
 		}
 	} else {
-		t, err = template.ParseFiles("./templates/resptype_method.tpl", "./templates/description.tpl")
+		t, err = template.ParseFiles("./templates/resptype_method.go.tpl", "./templates/description.go.tpl")
 		if err != nil {
 			return err
 		}

…ernal/generate/templates/description.tpl …al/generate/templates/description.go.tplinternal/generate/templates/description.tpl renamed to internal/generate/templates/description.go.tpl internal/generate/templates/description.tpl renamed to internal/generate/templates/description.go.tpl

@@ -0,0 +1,3 @@
+{{splitDocString .Description}}
+{{.ValueType}} {{.Name}} {{.Value}}
+

internal/generate/templates/enum.go.tpl

@@ -0,0 +1,14 @@
+{{splitDocString .Description}}
+{{- if .Fields}}
+type {{.Name}} {{.Type}} {
+{{- range .Fields}}
+{{- if .Description}}
+	{{splitDocString .Description}}
+{{- end}}
+	{{.Name}} {{.Type}} {{.SerializationInfo}}
+{{- end}}
+}
+
+{{else}}
+type {{.Name}} {{.Type}}
+{{end -}}

…al/generate/templates/listall_method.tpl …generate/templates/listall_method.go.tplinternal/generate/templates/listall_method.tpl renamed to internal/generate/templates/listall_method.go.tpl internal/generate/templates/listall_method.tpl renamed to internal/generate/templates/listall_method.go.tpl

@@ -0,0 +1,17 @@
+// Validate verifies all required fields for {{.AssociatedType}} are set
+func (p *{{.AssociatedType}}) Validate() error {
+	v := new(Validator)
+{{- range .RequiredObjects}}
+	v.HasRequiredObj(p.{{.}}, "{{.}}")
+{{- end}}
+{{- range .RequiredStrings}}
+	v.HasRequiredStr(string(p.{{.}}), "{{.}}")
+{{- end}}
+{{- range .RequiredNums}}
+	v.HasRequiredNum(p.{{.}}, "{{.}}")
+{{- end}}
+	if !v.IsValid() {
+		return fmt.Errorf("validation error:\n%v", v.Error())
+	}
+	return nil
+}