entproto: implement list service method (#162)

* entproto: generate list method for service annotations

For #2107

* protoc-gen-entgrpc: generate list method handler code

For #2107

* entproto: re-generate schema

For #2107

* entproto: implement list method unit test

For #2107

* entproto: appease the linter

For #2107

* entproto: fix typo in service.go

For #2107

* protoc-gen-entgrpc: add base64 encoding to page token

For #2107

* entproto: re-generate schema

For #2107

* entproto: increase MaxPageSize

For #2107

* entproto: change page token to string

For #2107

* entproto: revert infra change

For #2107

* protoc-gen-entgrpc: simplify page token wrapping

For #2107

* entproto: re-generate schema

For #2107

* entproto: simplify list method test

For #2107

* protoc-gen-entgrpc: throw template error for unsupported id types

* protoc-gen-entgrpc: adjust formatting in method_list.tmpl

Co-authored-by: Ariel Mashraki <[email protected]>

* entproto: adjust formatting in service.go

Co-authored-by: Ariel Mashraki <[email protected]>

* entproto: go fmt service.go

* entproto: re-generate schema

* entproto: throw error in list method proto generation for unsupported id

* protoc-gen-entgrpc: remove throwError

* entproto: re-generate schema

Co-authored-by: Ariel Mashraki <[email protected]>

entproto/cmd/protoc-gen-entgrpc/template/method_list.tmpl

@@ -0,0 +1,77 @@
+{{- /*gotype: entgo.io/contrib/entproto/cmd/protoc-gen-entgrpc.methodInput*/ -}}
+{{ define "method_list" }}
+    {{- $inputName := .Method.Input.GoIdent.GoName -}}
+    var (
+        err error
+        entList []*ent.{{ .G.EntType.Name }}
+        pageSize int
+    )
+    pageSize = int(req.GetPageSize())
+    switch {
+    case pageSize < 0:
+        return nil, {{ statusErrf "InvalidArgument" "page size cannot be less than zero" }}
+    case pageSize == 0 || pageSize > entproto.MaxPageSize:
+        pageSize = {{ qualify "entgo.io/contrib/entproto" "MaxPageSize" }}
+    }
+    listQuery := svc.client.{{ .G.EntType.Name }}.Query().
+        Order(ent.Desc({{ qualify (print (unquote .G.EntPackage.String) "/" .G.EntType.Package) "FieldID" }})).
+        Limit(pageSize + 1)
+    if req.GetPageToken() != "" {
+        bytes, err := {{ qualify "encoding/base64" "StdEncoding.DecodeString" }}(req.PageToken)
+        if err != nil {
+            return nil, status.Errorf(codes.InvalidArgument, "page token is invalid")
+        }
+        {{- if .G.EntType.ID.IsInt }}
+            token, err := {{ qualify "strconv" "ParseInt" }}(string(bytes), 10, 32)
+            if err != nil {
+                return nil, status.Errorf(codes.InvalidArgument, "page token is invalid")
+            }
+            pageToken := int(token)
+        {{- else if .G.EntType.ID.IsUUID }}
+            pageToken, err := {{ qualify "github.com/google/uuid" "ParseBytes" }}(bytes)
+            if err != nil {
+                return nil, status.Errorf(codes.InvalidArgument, "page token is invalid")
+            }
+        {{- else if .G.EntType.ID.IsString }}
+            pageToken := string(bytes)
+        {{- end }}
+        listQuery = listQuery.
+            Where({{ qualify (print (unquote .G.EntPackage.String) "/" .G.EntType.Package) "IDLTE" }}(pageToken))
+    }
+    switch req.GetView() {
+    case {{ $inputName }}_VIEW_UNSPECIFIED, {{ $inputName }}_BASIC:
+        entList, err = listQuery.All(ctx)
+    case {{ $inputName }}_WITH_EDGE_IDS:
+        entList, err = listQuery.
+            {{ range .G.FieldMap.Edges }}
+                {{- $et := .EntEdge.Type -}}
+                With{{ .EntEdge.StructField }}(func(query *ent.{{ $et.Name }}Query) {
+                    query.Select({{  qualify (print (unquote $.G.EntPackage.String) "/" $et.Package ) $et.ID.Constant  }})
+                }).
+            {{ end }}
+            All(ctx)
+    }
+    switch {
+    case err == nil:
+        var nextPageToken string
+        if len(entList) == pageSize + 1 {
+		nextPageToken = {{ qualify "encoding/base64" "StdEncoding.EncodeToString" }}(
+		    []byte({{ qualify "fmt" "Sprintf" }}("%v", entList[len(entList)-1].ID)))
+		entList = entList[:len(entList)-1]
+        }
+        var pbList []*{{ .G.EntType.Name }}
+        for _, entEntity := range entList {
+            pbEntity, err := toProto{{ .G.EntType.Name }}(entEntity)
+            if err != nil {
+                return nil, {{ statusErrf "Internal" "internal error: %s" "err" }}
+            }
+            pbList = append(pbList, pbEntity)
+        }
+        return &List{{ .G.EntType.Name }}Response{
+            {{ .G.EntType.Name }}List: pbList,
+            NextPageToken: nextPageToken,
+        }, nil
+    default:
+        return nil, {{ statusErrf "Internal" "internal error: %s" "err" }}
+    }
+{{ end }}

entproto/cmd/protoc-gen-entgrpc/template/service.tmpl

@@ -34,6 +34,8 @@ func New{{ .Service.GoName }}(client *{{ .EntPackage.Ident "Client" | ident }})
             {{ template "method_delete" (method .) }}
         {{- else if or (eq $methodName "Create") (eq $methodName "Update") }}
             {{ template "method_mutate" (method .) }}
+        {{- else if eq $methodName "List" }}
+            {{ template "method_list" (method .) }}
         {{- end }}
     }
 {{ end }}