feat(codegen): convert-keys run option (#199)

[Breaking Change] this commit introduces a new run option called `convert-keys` as discussed in #129.

Supported values: `snake`, `camel`, `kebab`, `none`. Default value is `none`.

---------

Co-authored-by: Louis FRADIN <louis.fradin@gmail.com>

README.md

@@ -288,7 +288,9 @@ your broker to the generated code.
 
 ## CLI options
 
-The default options for oapi-codegen will generate everything; user, application,
+### Generation parts (`-g`)
+
+The default options for asyncapi-codegen will generate everything; user, application,
 and type definitions but you can generate subsets of those via the -generate
 flag. It defaults to user,application,types
 but you can specify any combination of those.
@@ -303,6 +305,40 @@ Here are the universal parts that you can generate:
   This will be everything under `#components`, as well as request parameter,
   request body, and response type objects.
 
+### JSON keys conversion (`--convert-keys`)
+
+By default, the generation will use the key specified in the asyncapi codegen.
+This is also called the `none` convertion. You can also convert your keys to
+`snake`, `camel`, or `kebab`.
+
+#### Example
+
+Given this schema:
+
+```yaml
+Payload:
+  type: object
+  properties:
+    This_is a-Property:
+      type: string
+```
+
+Here are the generated JSON sent, given by the different options:
+
+```json
+/* No conversion (none) */
+{ "This_is a-Property": "value" }
+
+/* Camel case (camel) */
+{ "ThisIsAProperty": "value" }
+
+/* Kebab case (kebab) */
+{ "this-is-a-property": "value" }
+
+/* Snale case (snake) */
+{ "this_is_a_property": "value" }
+```
+
 ## Advanced topics
 
 ### Middlewares

cmd/asyncapi-codegen/config.go

@@ -35,6 +35,10 @@ type Flags struct {
 	// DisableFormatting states if the formatting should be disabled when
 	// writing the generated code
 	DisableFormatting bool
+
+	// ConvertKeys defines a schema property keys conversion strategy.
+	// Supported values: snake, camel, kebab, none
+	ConvertKeys string
 }
 
 // ProcessFlags processes command line flags and fill the Flags structure with them.
@@ -46,6 +50,8 @@ func ProcessFlags() Flags {
 	flag.StringVar(&f.PackageName, "p", "asyncapi", "Golang package name")
 	flag.StringVar(&f.Generate, "g", "user,application,types", "Generation options")
 	flag.BoolVar(&f.DisableFormatting, "disable-formatting", false, "Disables the code generation formatting")
+	flag.StringVar(&f.ConvertKeys, "convert-keys", "none",
+		"Schema property key names conversion strategy. Supported values: snake, camel, kebab, none")
 
 	flag.Parse()
 
@@ -58,6 +64,7 @@ func (f Flags) ToCodegenOptions() (options.Options, error) {
 		OutputPath:        f.OutputPath,
 		PackageName:       f.PackageName,
 		DisableFormatting: f.DisableFormatting,
+		ConvertKeys:       f.ConvertKeys,
 	}
 
 	if f.Generate != "" {

cmd/asyncapi-codegen/main.go

@@ -5,6 +5,7 @@ import (
 	"os"
 
 	"github.com/lerenn/asyncapi-codegen/pkg/codegen"
+	"github.com/lerenn/asyncapi-codegen/pkg/utils/template"
 )
 
 func run() int {
@@ -22,6 +23,11 @@ func run() int {
 		return 255
 	}
 
+	if err := template.SetConvertKeyFn(opt.ConvertKeys); err != nil {
+		fmt.Fprintf(os.Stderr, "%s\n", err.Error())
+		return 255
+	}
+
 	if err := cg.Generate(opt); err != nil {
 		fmt.Fprintf(os.Stderr, "%s\n", err.Error())
 		return 255

go.mod

@@ -33,6 +33,7 @@ require (
 	github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 // indirect
 	github.com/go-git/go-billy/v5 v5.5.0 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/iancoleman/strcase v0.3.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
 	github.com/kevinburke/ssh_config v1.2.0 // indirect

go.sum

@@ -52,6 +52,8 @@ github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/uuid v1.3.1 h1:KjJaJ9iWZ3jOFZIf1Lqf4laDRCasjl0BCmnEGxkdLb4=
 github.com/google/uuid v1.3.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/iancoleman/strcase v0.3.0 h1:nTXanmYxhfFAMjZL34Ov6gkzEsSJZ5DbhxWjvSASxEI=
+github.com/iancoleman/strcase v0.3.0/go.mod h1:iwCmte+B7n89clKwxIoIXy/HfoL7AsD47ZCWhYzw7ho=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOlocH6Fxy8MmwDt+yVQYULKfN0RoTN8A=

pkg/codegen/generators/v2/templates/marshaling/additional_properties.tmpl

@@ -44,10 +44,10 @@ func (t *{{ .Name }}) UnmarshalJSON(data []byte) error {
     t.AdditionalProperties = make(map[string]{{template "schema-name" .AdditionalProperties}}, len(m))
     for k, v := range m {
         switch k {
-            {{- range $key, $value := .Properties -}}
-                case "{{snakeCase $key}}":
+            {{ range $key, $value := .Properties -}}
+                case "{{convertKey $key}}":
                     continue
-            {{- end}}
+            {{ end -}}
         default:
             t.AdditionalProperties[k] = v
         }

pkg/codegen/generators/v2/templates/schema_definition.tmpl

@@ -15,7 +15,7 @@ type {{ .Name }} struct {
     {{else if and $value.ReferenceTo $value.ReferenceTo.Description}}
     // Description: {{$value.ReferenceTo.Description}}
     {{end -}}
-    {{namify $key}} {{if and (not (isRequired $ $key)) (ne $value.Type "array")}}*{{end}}{{template "schema-name" $value}} `json:"{{snakeCase $key}}"`
+    {{namify $key}} {{if and (not (isRequired $ $key)) (ne $value.Type "array")}}*{{end}}{{template "schema-name" $value}} `json:"{{convertKey $key}}"`
     {{end -}}
 
     {{- if .AdditionalProperties}}

pkg/codegen/generators/v3/templates/marshaling/additional_properties.tmpl

@@ -44,10 +44,10 @@ func (t *{{ .Name }}) UnmarshalJSON(data []byte) error {
     t.AdditionalProperties = make(map[string]{{template "schema-name" .AdditionalProperties}}, len(m))
     for k, v := range m {
         switch k {
-            {{- range $key, $value := .Properties -}}
-                case "{{snakeCase $key}}":
+            {{ range $key, $value := .Properties -}}
+                case "{{convertKey $key}}":
                     continue
-            {{- end}}
+            {{ end -}}
         default:
             t.AdditionalProperties[k] = v
         }

pkg/codegen/generators/v3/templates/schema_definition.tmpl

@@ -15,7 +15,7 @@ type {{ .Name }} struct {
     {{else if and $value.ReferenceTo $value.ReferenceTo.Description}}
     // Description: {{$value.ReferenceTo.Description}}
     {{end -}}
-    {{namify $key}} {{if and (not (isRequired $ $key)) (ne $value.Type "array")}}*{{end}}{{template "schema-name" $value}} `json:"{{snakeCase $key}}"`
+    {{namify $key}} {{if and (not (isRequired $ $key)) (ne $value.Type "array")}}*{{end}}{{template "schema-name" $value}} `json:"{{convertKey $key}}"`
     {{end -}}
 
     {{- if .AdditionalProperties}}

pkg/codegen/options/options.go

@@ -24,4 +24,8 @@ type Options struct {
 	// DisableFormatting states if the formatting should be disabled when
 	// writing the generated code
 	DisableFormatting bool
+
+	// ConvertKeys defines a schema property keys conversion strategy.
+	// Supported values: snake, camel, kebab, none
+	ConvertKeys string
 }