Add pattern, support reference constraints on primitives, and add num…

…ber/integer constraints (#264)

* add pattern

* support primitive types having restraints

* Numeric types

* Fix a bug where primitve string types can't pattern match

* Fix lint

* Fix test case output

* Min int size

* remote refs

* fix more lint

* Use math.Round instead of directly casting first

* Try with floats instead...

* PR feedback, fix typos, and reversed old for exclusive min/max

README.md

@@ -121,16 +121,16 @@ only specific validations remain to be fully implemented.
     * [x] `type` (single)
     * [x] `type` (multiple; **note**: partial support, limited validation)
     * [ ] `const`
-  * [ ] Numeric validation (§6.2)
-    * [ ] `multipleOf`
-    * [ ] `maximum`
-    * [ ] `exclusiveMaximum`
-    * [ ] `minimum`
-    * [ ] `exclusiveMinimum`
-  * [ ] String validation (§6.3)
+  * [X] Numeric validation (§6.2)
+    * [X] `multipleOf`
+    * [X] `maximum`
+    * [X] `exclusiveMaximum`
+    * [X] `minimum`
+    * [X] `exclusiveMinimum`
+  * [X] String validation (§6.3)
     * [X] `maxLength`
     * [X] `minLength`
-    * [ ] `pattern`
+    * [X] `pattern`
   * [ ] Array validation (§6.4)
     * [X] `items`
     * [x] `maxItems`

go.mod

@@ -5,19 +5,22 @@ go 1.22.0
 toolchain go1.22.7
 
 require (
+	github.com/davecgh/go-spew v0.0.0-20161028175848-04cdfd42973b // indirect
+	github.com/fatih/color v1.17.0 // indirect
 	github.com/goccy/go-yaml v1.12.0
 	github.com/mitchellh/go-wordwrap v1.0.1
 	github.com/pkg/errors v0.9.1
 	github.com/sanity-io/litter v1.5.5
 	github.com/spf13/cobra v1.8.1
+	github.com/stretchr/testify v0.0.0-20161117074351-18a02ba4a312
 	golang.org/x/exp v0.0.0-20240909161429-701f63a606c0
 )
 
 require (
-	github.com/fatih/color v1.17.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/pmezard/go-difflib v0.0.0-20151028094244-d8ed2627bdf0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/sys v0.25.0 // indirect
 	golang.org/x/xerrors v0.0.0-20240903120638-7835f813f4da // indirect

main.go

@@ -31,6 +31,7 @@ var (
 	yamlExtensions      []string
 	tags                []string
 	structNameFromTitle bool
+	minSizedInts        bool
 
 	errFlagFormat = errors.New("flag must be in the format URI=PACKAGE")
 
@@ -75,6 +76,7 @@ var (
 				StructNameFromTitle: structNameFromTitle,
 				Tags:                tags,
 				OnlyModels:          onlyModels,
+				MinSizedInts:        minSizedInts,
 			}
 			for _, id := range allKeys(schemaPackageMap, schemaOutputMap, schemaRootTypeMap) {
 				mapping := generator.SchemaMapping{SchemaID: id}
@@ -166,6 +168,11 @@ also look for foo.json if --resolve-extension json is provided.`)
 		"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`)
+	rootCmd.PersistentFlags().BoolVar(
+		&minSizedInts,
+		"min-sized-ints",
+		false,
+		"Uses sized int and uint values based on the min and max values for the field")
 
 	abortWithErr(rootCmd.Execute())
 }

pkg/codegen/utils.go

@@ -3,7 +3,9 @@ package codegen
 import (
 	"errors"
 	"fmt"
+	"math"
 
+	"github.com/atombender/go-jsonschema/pkg/mathutils"
 	"github.com/atombender/go-jsonschema/pkg/schemas"
 )
 
@@ -33,7 +35,16 @@ func isPointerType(t Type) bool {
 	}
 }
 
-func PrimitiveTypeFromJSONSchemaType(jsType, format string, pointer bool) (Type, error) {
+func PrimitiveTypeFromJSONSchemaType(
+	jsType,
+	format string,
+	pointer,
+	minIntSize bool,
+	minimum **float64,
+	maximum **float64,
+	exclusiveMinimum **any,
+	exclusiveMaximum **any,
+) (Type, error) {
 	var t Type
 
 	switch jsType {
@@ -119,6 +130,22 @@ func PrimitiveTypeFromJSONSchemaType(jsType, format string, pointer bool) (Type,
 
 	case schemas.TypeNameInteger:
 		t := PrimitiveType{"int"}
+
+		if minIntSize {
+			newType, removeMin, removeMax := getMinIntType(*minimum, *maximum, *exclusiveMinimum, *exclusiveMaximum)
+			t.Type = newType
+
+			if removeMin {
+				*minimum = nil
+				*exclusiveMaximum = nil
+			}
+
+			if removeMax {
+				*maximum = nil
+				*exclusiveMinimum = nil
+			}
+		}
+
 		if pointer {
 			return WrapTypeInPointer(t), nil
 		}
@@ -142,3 +169,90 @@ func PrimitiveTypeFromJSONSchemaType(jsType, format string, pointer bool) (Type,
 
 	return nil, fmt.Errorf("%w %q", errUnknownJSONSchemaType, jsType)
 }
+
+// getMinIntType returns the smallest integer type that can represent the bounds, and if the bounds can be removed.
+func getMinIntType(
+	minimum, maximum *float64, exclusiveMinimum, exclusiveMaximum *any,
+) (string, bool, bool) {
+	nMin, nMax, nExclusiveMin, nExclusiveMax := mathutils.NormalizeBounds(
+		minimum, maximum, exclusiveMinimum, exclusiveMaximum,
+	)
+
+	if nExclusiveMin && nMin != nil {
+		*nMin += 1.0
+	}
+
+	if nExclusiveMax && nMax != nil {
+		*nMax -= 1.0
+	}
+
+	if nMin != nil && *nMin >= 0 {
+		return adjustForUnsignedBounds(nMin, nMax)
+	}
+
+	return adjustForSignedBounds(nMin, nMax)
+}
+
+const i64 = "int64"
+
+func adjustForSignedBounds(nMin, nMax *float64) (string, bool, bool) {
+	var minRounded, maxRounded float64
+
+	if nMin != nil {
+		minRounded = math.Round(*nMin)
+	}
+
+	if nMax != nil {
+		maxRounded = math.Round(*nMax)
+	}
+
+	switch {
+	case nMin == nil && nMax == nil:
+		return i64, false, false
+
+	case nMin == nil:
+		return i64, false, maxRounded == float64(math.MaxInt64)
+
+	case nMax == nil:
+		return i64, minRounded == float64(math.MinInt64), false
+
+	case minRounded < float64(math.MinInt32) || maxRounded > float64(math.MaxInt32):
+		return i64, minRounded == float64(math.MinInt64), maxRounded == float64(math.MaxInt64)
+
+	case minRounded < float64(math.MinInt16) || maxRounded > float64(math.MaxInt16):
+		return "int32", minRounded == float64(math.MinInt32), maxRounded == float64(math.MaxInt32)
+
+	case minRounded < float64(math.MinInt8) || maxRounded > float64(math.MaxInt8):
+		return "int16", minRounded == float64(math.MinInt16), maxRounded == float64(math.MaxInt16)
+
+	default:
+		return "int8", minRounded == float64(math.MinInt8), maxRounded == float64(math.MaxInt8)
+	}
+}
+
+func adjustForUnsignedBounds(nMin, nMax *float64) (string, bool, bool) {
+	removeMin := nMin != nil && *nMin == 0.0
+
+	var maxRounded float64
+
+	if nMax != nil {
+		maxRounded = math.Round(*nMax)
+	}
+
+	switch {
+	case nMax == nil:
+		return "uint64", removeMin, false
+
+	case maxRounded > float64(math.MaxUint32):
+		return "uint64", removeMin, maxRounded == float64(math.MaxUint64)
+
+	case maxRounded > float64(math.MaxUint16):
+		return "uint32", removeMin, maxRounded == float64(math.MaxUint32)
+
+	case maxRounded > float64(math.MaxUint8):
+		return "uint16", removeMin, maxRounded == float64(math.MaxUint16)
+
+	default:
+		return "uint8", removeMin, maxRounded == float64(math.MaxUint8)
+	}
+}

pkg/generator/config.go

@@ -1,5 +1,7 @@
 package generator
 
+import "github.com/atombender/go-jsonschema/pkg/schemas"
+
 type Config struct {
 	SchemaMappings      []SchemaMapping
 	ExtraImports        bool
@@ -12,6 +14,8 @@ type Config struct {
 	Warner              func(string)
 	Tags                []string
 	OnlyModels          bool
+	MinSizedInts        bool
+	Loader              schemas.Loader
 }
 
 type SchemaMapping struct {

pkg/generator/generate.go

@@ -25,21 +25,19 @@ var (
 	errEnumNonPrimitiveVal            = errors.New("enum has non-primitive value")
 	errMapURIToPackageName            = errors.New("unable to map schema URI to Go package name")
 	errExpectedNamedType              = errors.New("expected named type")
-	errUnsupportedRefFormat           = errors.New("unsupported $ref format")
 	errConflictSameFile               = errors.New("conflict: same file")
 	errDefinitionDoesNotExistInSchema = errors.New("definition does not exist in schema")
 	errCannotGenerateReferencedType   = errors.New("cannot generate referenced type")
 )
 
 type Generator struct {
-	caser                 *text.Caser
-	config                Config
-	inScope               map[qualifiedDefinition]struct{}
-	outputs               map[string]*output
-	schemaCacheByFileName map[string]*schemas.Schema
-	warner                func(string)
-	formatters            []formatter
-	fileLoader            schemas.Loader
+	caser      *text.Caser
+	config     Config
+	inScope    map[qualifiedDefinition]struct{}
+	outputs    map[string]*output
+	warner     func(string)
+	formatters []formatter
+	loader     schemas.Loader
 }
 
 type qualifiedDefinition struct {
@@ -56,19 +54,18 @@ func New(config Config) (*Generator, error) {
 	}
 
 	generator := &Generator{
-		caser:                 text.NewCaser(config.Capitalizations, config.ResolveExtensions),
-		config:                config,
-		inScope:               map[qualifiedDefinition]struct{}{},
-		outputs:               map[string]*output{},
-		schemaCacheByFileName: map[string]*schemas.Schema{},
-		warner:                config.Warner,
-		formatters:            formatters,
+		caser:      text.NewCaser(config.Capitalizations, config.ResolveExtensions),
+		config:     config,
+		inScope:    map[qualifiedDefinition]struct{}{},
+		outputs:    map[string]*output{},
+		warner:     config.Warner,
+		formatters: formatters,
+		loader:     config.Loader,
 	}
 
-	generator.fileLoader = schemas.NewCachedLoader(
-		schemas.NewFileLoader(config.ResolveExtensions, config.YAMLExtensions),
-		generator.schemaCacheByFileName,
-	)
+	if config.Loader == nil {
+		generator.loader = schemas.NewDefaultCacheLoader(config.ResolveExtensions, config.YAMLExtensions)
+	}
 
 	return generator, nil
 }
@@ -125,7 +122,7 @@ func (g *Generator) DoFile(fileName string) error {
 			return fmt.Errorf("error parsing from standard input: %w", err)
 		}
 	} else {
-		schema, err = g.fileLoader.Load(fileName, "")
+		schema, err = g.loader.Load(fileName, "")
 		if err != nil {
 			return fmt.Errorf("error parsing from file %s: %w", fileName, err)
 		}

pkg/generator/json_formatter.go

@@ -13,29 +13,44 @@ const (
 type jsonFormatter struct{}
 
 func (jf *jsonFormatter) generate(declType codegen.TypeDecl, validators []validator) func(*codegen.Emitter) {
+	var beforeValidators []validator
+
+	var afterValidators []validator
+
+	forceBefore := false
+
+	for _, v := range validators {
+		desc := v.desc()
+		if desc.beforeJSONUnmarshal {
+			beforeValidators = append(beforeValidators, v)
+		} else {
+			afterValidators = append(afterValidators, v)
+			forceBefore = forceBefore || desc.requiresRawAfter
+		}
+	}
+
 	return func(out *codegen.Emitter) {
 		out.Commentf("Unmarshal%s implements %s.Unmarshaler.", strings.ToUpper(formatJSON), formatJSON)
 		out.Printlnf("func (j *%s) Unmarshal%s(b []byte) error {", declType.Name, strings.ToUpper(formatJSON))
 		out.Indent(1)
-		out.Printlnf("var %s map[string]interface{}", varNameRawMap)
-		out.Printlnf("if err := %s.Unmarshal(b, &%s); err != nil { return err }",
-			formatJSON, varNameRawMap)
 
-		for _, v := range validators {
-			if v.desc().beforeJSONUnmarshal {
-				v.generate(out)
-			}
+		if forceBefore || len(beforeValidators) != 0 {
+			out.Printlnf("var %s map[string]interface{}", varNameRawMap)
+			out.Printlnf("if err := %s.Unmarshal(b, &%s); err != nil { return err }",
+				formatJSON, varNameRawMap)
+		}
+
+		for _, v := range beforeValidators {
+			v.generate(out)
 		}
 
 		out.Printlnf("type Plain %s", declType.Name)
 		out.Printlnf("var %s Plain", varNamePlainStruct)
 		out.Printlnf("if err := %s.Unmarshal(b, &%s); err != nil { return err }",
 			formatJSON, varNamePlainStruct)
 
-		for _, v := range validators {
-			if !v.desc().beforeJSONUnmarshal {
-				v.generate(out)
-			}
+		for _, v := range afterValidators {
+			v.generate(out)
 		}
 
 		out.Printlnf("*j = %s(%s)", declType.Name, varNamePlainStruct)