Revert "JSON Schema generator for golang types (#167)"

This reverts commit b3a30166f6.
This commit is contained in:
shreyas-goenka 2023-01-20 16:56:49 +01:00 committed by GitHub
parent b3a30166f6
commit f5691ba5d8
7 changed files with 2 additions and 1666 deletions

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@ -37,7 +37,7 @@ type Root struct {
// Resources contains a description of all Databricks resources
// to deploy in this bundle (e.g. jobs, pipelines, etc.).
Resources Resources `json:"resources,omitempty"`
Resources Resources `json:"resources"`
// Environments can be used to differentiate settings and resources between
// bundle deployment environments (e.g. development, staging, production).

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@ -1,12 +0,0 @@
documentation: Root of the bundle config
children:
bundle:
documentation: |
Bundle contains details about this bundle, such as its name,
version of the spec (TODO), default cluster, default warehouse, etc.
children:
environment:
documentation: Environment is set by the mutator that selects the environment.
artifacts:
documentation: Artifacts contains a description of all code artifacts in this bundle.

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@ -1,25 +0,0 @@
package schema
import (
"os"
"gopkg.in/yaml.v2"
)
type Docs struct {
Documentation string `json:"documentation"`
Children map[string]Docs `json:"children"`
}
func LoadDocs(path string) (*Docs, error) {
bytes, err := os.ReadFile(path)
if err != nil {
return nil, err
}
docs := Docs{}
err = yaml.Unmarshal(bytes, &docs)
if err != nil {
return nil, err
}
return &docs, nil
}

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@ -1,274 +0,0 @@
package schema
import (
"container/list"
"fmt"
"reflect"
"strings"
)
// defines schema for a json object
type Schema struct {
// Type of the object
Type JavascriptType `json:"type,omitempty"`
// Description of the object. This is rendered as inline documentation in the
// IDE. This is manually injected here using schema.Docs
Description string `json:"description,omitempty"`
// Schemas for the fields of an struct. The keys are the first json tag.
// The values are the schema for the type of the field
Properties map[string]*Schema `json:"properties,omitempty"`
// The schema for all values of an array
Items *Schema `json:"items,omitempty"`
// The schema for any properties not mentioned in the Schema.Properties field.
// this validates maps[string]any in bundle configuration
// OR
// A boolean type with value false. Setting false here validates that all
// properties in the config have been defined in the json schema as properties
//
// Its type during runtime will either be *Schema or bool
AdditionalProperties any `json:"additionalProperties,omitempty"`
// Required properties for the object. Any fields missing the "omitempty"
// json tag will be included
Required []string `json:"required,omitempty"`
}
// This function translates golang types into json schema. Here is the mapping
// between json schema types and golang types
//
// - GolangType -> Javascript type / Json Schema2
//
// - bool -> boolean
//
// - string -> string
//
// - int (all variants) -> number
//
// - float (all variants) -> number
//
// - map[string]MyStruct -> { type: object, additionalProperties: {}}
// for details visit: https://json-schema.org/understanding-json-schema/reference/object.html#additional-properties
//
// - []MyStruct -> {type: array, items: {}}
// for details visit: https://json-schema.org/understanding-json-schema/reference/array.html#items
//
// - []MyStruct -> {type: object, properties: {}, additionalProperties: false}
// for details visit: https://json-schema.org/understanding-json-schema/reference/object.html#properties
func NewSchema(golangType reflect.Type, docs *Docs) (*Schema, error) {
tracker := newTracker()
schema, err := safeToSchema(golangType, docs, "", tracker)
if err != nil {
return nil, tracker.errWithTrace(err.Error())
}
return schema, nil
}
type JavascriptType string
const (
Invalid JavascriptType = "invalid"
Boolean JavascriptType = "boolean"
String JavascriptType = "string"
Number JavascriptType = "number"
Object JavascriptType = "object"
Array JavascriptType = "array"
)
func javascriptType(golangType reflect.Type) (JavascriptType, error) {
switch golangType.Kind() {
case reflect.Bool:
return Boolean, nil
case reflect.String:
return String, nil
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
reflect.Float32, reflect.Float64:
return Number, nil
case reflect.Struct:
return Object, nil
case reflect.Map:
if golangType.Key().Kind() != reflect.String {
return Invalid, fmt.Errorf("only strings map keys are valid. key type: %v", golangType.Key().Kind())
}
return Object, nil
case reflect.Array, reflect.Slice:
return Array, nil
default:
return Invalid, fmt.Errorf("unhandled golang type: %s", golangType)
}
}
// A wrapper over toSchema function to:
// 1. Detect cycles in the bundle config struct.
// 2. Update tracker
//
// params:
//
// - golangType: Golang type to generate json schema for
//
// - docs: Contains documentation to be injected into the generated json schema
//
// - traceId: An identifier for the current type, to trace recursive traversal.
// Its value is the first json tag in case of struct fields and "" in other cases
// like array, map or no json tags
//
// - tracker: Keeps track of types / traceIds seen during recursive traversal
func safeToSchema(golangType reflect.Type, docs *Docs, traceId string, tracker *tracker) (*Schema, error) {
// WE ERROR OUT IF THERE ARE CYCLES IN THE JSON SCHEMA
// There are mechanisms to deal with cycles though recursive identifiers in json
// schema. However if we use them, we would need to make sure we are able to detect
// cycles where two properties (directly or indirectly) pointing to each other
//
// see: https://json-schema.org/understanding-json-schema/structuring.html#recursion
// for details
if tracker.hasCycle(golangType) {
return nil, fmt.Errorf("cycle detected")
}
tracker.push(golangType, traceId)
props, err := toSchema(golangType, docs, tracker)
if err != nil {
return nil, err
}
tracker.pop(golangType)
return props, nil
}
// This function returns all member fields of the provided type.
// If the type has embedded (aka anonymous) fields, this function traverses
// those in a breadth first manner
func getStructFields(golangType reflect.Type) []reflect.StructField {
fields := []reflect.StructField{}
bfsQueue := list.New()
for i := 0; i < golangType.NumField(); i++ {
bfsQueue.PushBack(golangType.Field(i))
}
for bfsQueue.Len() > 0 {
front := bfsQueue.Front()
field := front.Value.(reflect.StructField)
bfsQueue.Remove(front)
if !field.Anonymous {
fields = append(fields, field)
continue
}
fieldType := field.Type
if fieldType.Kind() == reflect.Pointer {
fieldType = fieldType.Elem()
}
for i := 0; i < fieldType.NumField(); i++ {
bfsQueue.PushBack(fieldType.Field(i))
}
}
return fields
}
func toSchema(golangType reflect.Type, docs *Docs, tracker *tracker) (*Schema, error) {
// *Struct and Struct generate identical json schemas
if golangType.Kind() == reflect.Pointer {
return safeToSchema(golangType.Elem(), docs, "", tracker)
}
if golangType.Kind() == reflect.Interface {
return &Schema{}, nil
}
rootJavascriptType, err := javascriptType(golangType)
if err != nil {
return nil, err
}
schema := &Schema{Type: rootJavascriptType}
if docs != nil {
schema.Description = docs.Documentation
}
// case array/slice
if golangType.Kind() == reflect.Array || golangType.Kind() == reflect.Slice {
elemGolangType := golangType.Elem()
elemJavascriptType, err := javascriptType(elemGolangType)
if err != nil {
return nil, err
}
elemProps, err := safeToSchema(elemGolangType, docs, "", tracker)
if err != nil {
return nil, err
}
schema.Items = &Schema{
Type: elemJavascriptType,
Properties: elemProps.Properties,
AdditionalProperties: elemProps.AdditionalProperties,
Items: elemProps.Items,
Required: elemProps.Required,
}
}
// case map
if golangType.Kind() == reflect.Map {
if golangType.Key().Kind() != reflect.String {
return nil, fmt.Errorf("only string keyed maps allowed")
}
schema.AdditionalProperties, err = safeToSchema(golangType.Elem(), docs, "", tracker)
if err != nil {
return nil, err
}
}
// case struct
if golangType.Kind() == reflect.Struct {
children := getStructFields(golangType)
properties := map[string]*Schema{}
required := []string{}
for _, child := range children {
// get child json tags
childJsonTag := strings.Split(child.Tag.Get("json"), ",")
childName := childJsonTag[0]
// skip children that have no json tags, the first json tag is ""
// or the first json tag is "-"
if childName == "" || childName == "-" {
continue
}
// get docs for the child if they exist
var childDocs *Docs
if docs != nil {
if val, ok := docs.Children[childName]; ok {
childDocs = &val
}
}
// compute if the child is a required field. Determined by the
// presence of "omitempty" in the json tags
hasOmitEmptyTag := false
for i := 1; i < len(childJsonTag); i++ {
if childJsonTag[i] == "omitempty" {
hasOmitEmptyTag = true
}
}
if !hasOmitEmptyTag {
required = append(required, childName)
}
// compute Schema.Properties for the child recursively
fieldProps, err := safeToSchema(child.Type, childDocs, childName, tracker)
if err != nil {
return nil, err
}
properties[childName] = fieldProps
}
schema.AdditionalProperties = false
schema.Properties = properties
schema.Required = required
}
return schema, nil
}

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@ -1,54 +0,0 @@
package schema
import (
"container/list"
"fmt"
"reflect"
)
type tracker struct {
// Types encountered in current path during the recursive traversal. Used to
// check for cycles
seenTypes map[reflect.Type]struct{}
// List of field names encountered in current path during the recursive traversal.
// Used to hydrate errors with path to the exact node where error occured.
//
// The field names here are the first tag in the json tags of struct field.
debugTrace *list.List
}
func newTracker() *tracker {
return &tracker{
seenTypes: map[reflect.Type]struct{}{},
debugTrace: list.New(),
}
}
func (t *tracker) errWithTrace(prefix string) error {
traceString := "root"
curr := t.debugTrace.Front()
for curr != nil {
if curr.Value.(string) != "" {
traceString += " -> " + curr.Value.(string)
}
curr = curr.Next()
}
return fmt.Errorf("[ERROR] " + prefix + ". traversal trace: " + traceString)
}
func (t *tracker) hasCycle(golangType reflect.Type) bool {
_, ok := t.seenTypes[golangType]
return ok
}
func (t *tracker) push(nodeType reflect.Type, jsonName string) {
t.seenTypes[nodeType] = struct{}{}
t.debugTrace.PushBack(jsonName)
}
func (t *tracker) pop(nodeType reflect.Type) {
back := t.debugTrace.Back()
t.debugTrace.Remove(back)
delete(t.seenTypes, nodeType)
}

2
go.mod
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@ -57,6 +57,6 @@ require (
google.golang.org/genproto v0.0.0-20221206210731-b1a01be3a5f6 // indirect
google.golang.org/grpc v1.51.0 // indirect
google.golang.org/protobuf v1.28.1 // indirect
gopkg.in/yaml.v2 v2.4.0
gopkg.in/yaml.v2 v2.4.0 // indirect
gopkg.in/yaml.v3 v3.0.1 // indirect
)