feat: add support for --tags flag

This feature allows users to configure which struct tags to generate. By
default it generates json, yaml, mapstructure.

Fix omissis#79

Signed-off-by: Alex Boten <aboten@lightstep.com>

Author: Alex Boten

cmd/gojsonschema/main.go

@@ -29,6 +29,7 @@ var (
 	capitalizations     []string
 	resolveExtensions   []string
 	yamlExtensions      []string
+	tags                []string
 	structNameFromTitle bool
 
 	errFlagFormat = errors.New("flag must be in the format URI=PACKAGE")
@@ -73,6 +74,7 @@ var (
 				ResolveExtensions:   resolveExtensions,
 				YAMLExtensions:      yamlExtensions,
 				StructNameFromTitle: structNameFromTitle,
+				Tags:                tags,
 			}
 			for _, id := range allKeys(schemaPackageMap, schemaOutputMap, schemaRootTypeMap) {
 				mapping := generator.SchemaMapping{SchemaID: id}
@@ -163,6 +165,8 @@ also look for foo.json if --resolve-extension json is provided.`)
 		`Add a file extension that should be recognized as YAML. Default are .yml, .yaml.`)
 	rootCmd.PersistentFlags().BoolVarP(&structNameFromTitle, "struct-name-from-title", "t", false,
 		"Use the schema title as the generated struct name")
+	rootCmd.PersistentFlags().StringSliceVar(&tags, "tags", []string{"json", "yaml", "mapstructure"},
+		`Specify which struct tags to generate. Defaults are json, yaml, mapstructure`)
 
 	abortWithErr(rootCmd.Execute())
 }

pkg/generator/generate.go

@@ -24,6 +24,7 @@ type Config struct {
 	DefaultOutputName   string
 	StructNameFromTitle bool
 	Warner              func(string)
+	Tags                []string
 }
 
 type SchemaMapping struct {
@@ -804,13 +805,20 @@ func (g *schemaGenerator) generateStructType(
 			SchemaType: prop,
 		}
 
+		tags := ""
+
 		if isRequired {
-			structField.Tags = fmt.Sprintf(`json:"%s" yaml:"%s" mapstructure:"%s"`, name, name, name)
+			for _, tag := range g.config.Tags {
+				tags += fmt.Sprintf(`%s:"%s" `, tag, name)
+			}
 		} else {
-			structField.Tags = fmt.Sprintf(`json:"%s,omitempty" yaml:"%s,omitempty" mapstructure:"%s,omitempty"`,
-				name, name, name)
+			for _, tag := range g.config.Tags {
+				tags += fmt.Sprintf(`%s:"%s,omitempty" `, tag, name)
+			}
 		}
 
+		structField.Tags = strings.TrimSpace(tags)
+
 		if structField.Comment == "" {
 			structField.Comment = fmt.Sprintf("%s corresponds to the JSON schema field %q.",
 				structField.Name, name)

tests/data/misc/tags.go.output

@@ -0,0 +1,14 @@
+// Code generated by github.com/atombender/go-jsonschema, DO NOT EDIT.
+
+package test
+
+type Tags struct {
+	// Html corresponds to the JSON schema field "html".
+	Html *string `yaml:"html,omitempty"`
+
+	// Id corresponds to the JSON schema field "id".
+	Id *string `yaml:"id,omitempty"`
+
+	// Url corresponds to the JSON schema field "url".
+	Url *string `yaml:"url,omitempty"`
+}

tests/data/misc/tags.json

@@ -0,0 +1,16 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "id": "https://example.com/case",
+  "type": "object",
+  "properties": {
+    "url": {
+      "type": "string"
+    },
+    "id": {
+      "type": "string"
+    },
+    "html": {
+      "type": "string"
+    }
+  }
+}

tests/integration_test.go

@@ -27,6 +27,7 @@ var (
 		Warner: func(message string) {
 			log.Printf("[from warner] %s", message)
 		},
+		Tags: []string{"json", "yaml", "mapstructure"},
 	}
 )
 
@@ -140,6 +141,14 @@ func TestExtraImportsAnotherYAML(t *testing.T) {
 	testExampleFile(t, cfg, "./data/extraImports/gopkgYAMLv2.json")
 }
 
+func TestTags(t *testing.T) {
+	t.Parallel()
+
+	cfg := basicConfig
+	cfg.Tags = []string{"yaml"}
+	testExampleFile(t, cfg, "./data/misc/tags.json")
+}
+
 func testExamples(t *testing.T, cfg generator.Config, dataDir string) {
 	t.Helper()