protoc-gen-ts/internal/plugin/servicegen.go

258 lines
7.3 KiB
Go

package plugin
import (
"fmt"
"strconv"
"strings"
"git.apinb.com/bsm-tools/protoc-gen-ts/internal/codegen"
"git.apinb.com/bsm-tools/protoc-gen-ts/internal/httprule"
"google.golang.org/protobuf/reflect/protoreflect"
)
type serviceGenerator struct {
pkg protoreflect.FullName
genHandler bool
service protoreflect.ServiceDescriptor
}
func (s serviceGenerator) Generate(f *codegen.File) error {
s.generateInterface(f)
if s.genHandler {
s.generateHandler(f)
}
return s.generateClient(f)
}
func (s serviceGenerator) generateInterface(f *codegen.File) {
commentGenerator{descriptor: s.service}.generateLeading(f, 0)
f.P("export interface ", descriptorTypeName(s.service), " {")
rangeMethods(s.service.Methods(), func(method protoreflect.MethodDescriptor) {
if !supportedMethod(method) {
return
}
commentGenerator{descriptor: method}.generateLeading(f, 1)
input := typeFromMessage(s.pkg, method.Input())
output := typeFromMessage(s.pkg, method.Output())
f.P(t(1), method.Name(), "(request: ", input.Reference(), "): Promise<", output.Reference(), ">;")
})
f.P("}")
f.P()
}
func (s serviceGenerator) generateHandler(f *codegen.File) {
f.P("type RequestType = {")
f.P(t(1), "path: string;")
f.P(t(1), "method: string;")
f.P(t(1), "body: string | null;")
f.P("};")
f.P()
f.P("type RequestHandler = (request: RequestType, meta: { service: string, method: string }) => Promise<unknown>;")
f.P()
}
func (s serviceGenerator) generateClient(f *codegen.File) error {
f.P(
"export function create",
descriptorTypeName(s.service),
"Client(",
"\n",
t(1),
"handler: RequestHandler",
"\n",
"): ",
descriptorTypeName(s.service),
" {",
)
f.P(t(1), "return {")
var methodErr error
rangeMethods(s.service.Methods(), func(method protoreflect.MethodDescriptor) {
if err := s.generateMethod(f, method); err != nil {
methodErr = fmt.Errorf("generate method %s: %w", method.Name(), err)
}
})
if methodErr != nil {
return methodErr
}
f.P(t(1), "};")
f.P("}")
return nil
}
func (s serviceGenerator) generateMethod(f *codegen.File, method protoreflect.MethodDescriptor) error {
loc := method.ParentFile().SourceLocations().ByDescriptor(method)
var comments string
if loc.TrailingComments != "" {
comments = comments + loc.TrailingComments
}
if loc.LeadingComments != "" {
comments = comments + loc.LeadingComments
}
AllSrvMethods = append(AllSrvMethods, SrvMethod{
PkgName: string(s.pkg.Name()),
ServiceName: string(s.service.Name()),
MethodName: string(method.Name()),
Comment: comments,
In: string(method.Input().Name()),
Out: string(method.Output().Name()),
})
outputType := typeFromMessage(s.pkg, method.Output())
r, ok := httprule.Get(method)
if !ok {
return nil
}
rule, err := httprule.ParseRule(r)
if err != nil {
return fmt.Errorf("parse http rule: %w", err)
}
f.P(t(2), method.Name(), "(request) { // eslint-disable-line @typescript-eslint/no-unused-vars")
s.generateMethodPathValidation(f, method.Input(), rule)
s.generateMethodPath(f, method.Input(), rule)
s.generateMethodBody(f, method.Input(), rule)
s.generateMethodQuery(f, method.Input(), rule)
f.P(t(3), "let uri = path;")
f.P(t(3), "if (queryParams.length > 0) {")
f.P(t(4), "uri += `?${queryParams.join(\"&\")}`")
f.P(t(3), "}")
f.P(t(3), "return handler({")
f.P(t(4), "path: uri,")
f.P(t(4), "method: ", strconv.Quote(rule.Method), ",")
f.P(t(4), "body,")
f.P(t(3), "}, {")
f.P(t(4), "service: \"", method.Parent().Name(), "\",")
f.P(t(4), "method: \"", method.Name(), "\",")
f.P(t(3), "}) as Promise<", outputType.Reference(), ">;")
f.P(t(2), "},")
return nil
}
func (s serviceGenerator) generateMethodPathValidation(
f *codegen.File,
input protoreflect.MessageDescriptor,
rule httprule.Rule,
) {
for _, seg := range rule.Template.Segments {
if seg.Kind != httprule.SegmentKindVariable {
continue
}
fp := seg.Variable.FieldPath
nullPath := nullPropagationPath(fp, input)
protoPath := strings.Join(fp, ".")
errMsg := "missing required field request." + protoPath
f.P(t(3), "if (!request.", nullPath, ") {")
f.P(t(4), "throw new Error(", strconv.Quote(errMsg), ");")
f.P(t(3), "}")
}
}
func (s serviceGenerator) generateMethodPath(
f *codegen.File,
input protoreflect.MessageDescriptor,
rule httprule.Rule,
) {
pathParts := make([]string, 0, len(rule.Template.Segments))
for _, seg := range rule.Template.Segments {
switch seg.Kind {
case httprule.SegmentKindVariable:
fieldPath := jsonPath(seg.Variable.FieldPath, input)
pathParts = append(pathParts, "${request."+fieldPath+"}")
case httprule.SegmentKindLiteral:
pathParts = append(pathParts, seg.Literal)
case httprule.SegmentKindMatchSingle: // TODO: Double check this and following case
pathParts = append(pathParts, "*")
case httprule.SegmentKindMatchMultiple:
pathParts = append(pathParts, "**")
}
}
path := strings.Join(pathParts, "/")
if rule.Template.Verb != "" {
path += ":" + rule.Template.Verb
}
f.P(t(3), "const path = `", path, "`; // eslint-disable-line quotes")
}
func (s serviceGenerator) generateMethodBody(
f *codegen.File,
input protoreflect.MessageDescriptor,
rule httprule.Rule,
) {
switch {
case rule.Body == "":
f.P(t(3), "const body = null;")
case rule.Body == "*":
f.P(t(3), "const body = JSON.stringify(request);")
default:
nullPath := nullPropagationPath(httprule.FieldPath{rule.Body}, input)
f.P(t(3), "const body = JSON.stringify(request?.", nullPath, " ?? {});")
}
}
func (s serviceGenerator) generateMethodQuery(
f *codegen.File,
input protoreflect.MessageDescriptor,
rule httprule.Rule,
) {
f.P(t(3), "const queryParams: string[] = [];")
// nothing in query
if rule.Body == "*" {
return
}
// fields covered by path
pathCovered := make(map[string]struct{})
for _, segment := range rule.Template.Segments {
if segment.Kind != httprule.SegmentKindVariable {
continue
}
pathCovered[segment.Variable.FieldPath.String()] = struct{}{}
}
walkJSONLeafFields(input, func(path httprule.FieldPath, field protoreflect.FieldDescriptor) {
if _, ok := pathCovered[path.String()]; ok {
return
}
if rule.Body != "" && path[0] == rule.Body {
return
}
nullPath := nullPropagationPath(path, input)
jp := jsonPath(path, input)
f.P(t(3), "if (request.", nullPath, ") {")
switch {
case field.IsList():
f.P(t(4), "request.", jp, ".forEach((x) => {")
f.P(t(5), "queryParams.push(`", jp, "=${encodeURIComponent(x.toString())}`)")
f.P(t(4), "})")
default:
f.P(t(4), "queryParams.push(`", jp, "=${encodeURIComponent(request.", jp, ".toString())}`)")
}
f.P(t(3), "}")
})
}
func supportedMethod(method protoreflect.MethodDescriptor) bool {
_, ok := httprule.Get(method)
return ok && !method.IsStreamingClient() && !method.IsStreamingServer()
}
func jsonPath(path httprule.FieldPath, message protoreflect.MessageDescriptor) string {
return strings.Join(jsonPathSegments(path, message), ".")
}
func nullPropagationPath(path httprule.FieldPath, message protoreflect.MessageDescriptor) string {
return strings.Join(jsonPathSegments(path, message), "?.")
}
func jsonPathSegments(path httprule.FieldPath, message protoreflect.MessageDescriptor) []string {
segs := make([]string, len(path))
for i, p := range path {
field := message.Fields().ByName(protoreflect.Name(p))
segs[i] = field.JSONName()
if i < len(path) {
message = field.Message()
}
}
return segs
}