Implement go.type.import meta for arbitrary import paths (#21)

* Implement go.type.import meta for arbitrary import paths

* Dynamic import paths based on client/server/importTypesFrom opts

* Fix stdlib/custom imports

* Example: Add uuid.UUID type and regenerate

Author: VojtechVitek

README.md

@@ -22,12 +22,13 @@ As you can see, the `-target` supports default `golang`, any git URI, or a local
 ### Set custom template variables
 Change any of the following values by passing `-option="Value"` CLI flag to `webrpc-gen`.
 
-| webrpc-gen -option   | Description                             | Default value              | Added in |
-|----------------------|-----------------------------------------|----------------------------|----------|
-| `-pkg=<name>`        | package name                            | `"proto"`                  |          |
-| `-client`            | generate client code                    | unset (`false`)            |          |
-| `-server`            | generate server code                    | unset (`false`)            |          |
-| `-legacyErrors=true` | enable legacy errors (v0.10.0 or older) | unset (`false`)            | v0.11.0  |
+| webrpc-gen -option       | Description                               | Default value              | Added in |
+|--------------------------|-------------------------------------------|----------------------------|----------|
+| `-pkg=<name>`            | package name                              | `"proto"`                  |          |
+| `-client`                | generate client code                      | unset (`false`)            |          |
+| `-server`                | generate server code                      | unset (`false`)            |          |
+| `-importTypesFrom=<pkg>` | do not generate types; import from a pkg  | unset (`""`)               | v0.12.0  |
+| `-legacyErrors=true`     | enable legacy errors (v0.10.0 or older)   | unset (`false`)            | v0.11.0  |
 
 Example:
 ```
@@ -36,25 +37,44 @@ webrpc-gen -schema=./proto.json -target=golang -out openapi.gen.yaml -pkg=main -
 
 ## Set custom Go field meta tags in your RIDL file
 
-| CLI option flag           | Description                                                      |
-|---------------------------|------------------------------------------------------------------|
-| `+ go.field.name = ID`    | Set custom field name                                            |
-| `+ go.field.type = int64` | Set custom field type (must be able to JSON unmarshal the value) |
-| `+ go.tag.json = id`      | Set `json:"id"` struct tag                                       |
-| `+ go.tag.db = id`        | Set `db:"id"` struct tag                                         |
+| CLI option flag                              | Description                                                      |
+|----------------------------------------------|------------------------------------------------------------------|
+| `+ go.field.name = ID`                       | Set custom field name                                            |
+| `+ go.field.type = uuid.UUID`                | Set custom field type (must be able to JSON unmarshal the value) |
+| `+ go.type.import = github.com/google/uuid`  | Set custom field type's import path                              |
+| `+ go.tag.json = id`                         | Set `json:"id"` struct tag                                       |
+| `+ go.tag.db = id`                           | Set `db:"id"` struct tag                                         |
 
 Example:
 ```ridl
-message User
-  - id: uint64
-    + go.field.name = ID
+struct User
+  - ID: int64
     + go.tag.db = id
     + go.tag.json = id
+  - UUID: string
+    + go.field.type = uuid.UUID
+    + go.type.import = github.com/google/uuid
+    + go.tag.json = uuid
+    + go.tag.db = uuid
+  - Age: int
+    + go.tag.db: age
+  - Name: string
+    + go.tag.db = name
+  - PasswordHash: string
+    + go.tag.db = passwd_hash
 ```
+
 will result in
+
 ```go
+import "github.com/google/uuid"
+
 type User struct {
-	ID uint64 `json:"id" db:"id"`
+	ID           int64     `json:"id" db:"id"`
+	UUID         uuid.UUID `json:"uuid" db:"uuid"`
+	Name         string    `db:"name"`
+	Age          int       `db:"age"`
+	PasswordHash string    `json:"-" db:"passwd_hash"`
 }
 ```
 

_examples/golang-basics/example.gen.go

@@ -10,11 +10,14 @@ enum Kind: uint32
 
 struct User
   - id: uint64
-    + json = id
     + go.field.name = ID
-    #+ go.field.type = int64
     + go.tag.db = id
 
+  - uuid: string
+    + go.tag.db = id
+    + go.field.type = uuid.UUID
+    + go.type.import = github.com/google/uuid
+
   - username: string
     + json = USERNAME
     + go.tag.db = username

_examples/golang-basics/example.ridl

@@ -9,6 +9,7 @@ require (
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/google/uuid v1.3.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

_examples/golang-basics/go.mod

@@ -3,6 +3,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-chi/chi/v5 v5.0.7 h1:rDTPXLDHGATaeHvVlLcR4Qe0zftYethFucbjVQ1PxU8=
 github.com/go-chi/chi/v5 v5.0.7/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

_examples/golang-basics/go.sum

@@ -1,5 +1,6 @@
 {{define "client"}}
 {{- $typeMap := .TypeMap -}}
+{{- $typePrefix := .TypePrefix -}}
 {{- if .Services -}}
 //
 // Client
@@ -34,22 +35,22 @@ func New{{.Name | firstLetterToUpper }}Client(addr string, client HTTPClient) {{
 {{- $inputs := $method.Inputs -}}
 {{- $outputs := $method.Outputs }}
 
-func (c *{{$serviceName}}) {{.Name}}(ctx context.Context{{range $_, $input := $inputs}}, {{$input.Name}} {{template "type" dict "Type" $input.Type "Optional" $input.Optional "TypeMap" $typeMap}}{{end}}) {{if len .Outputs}}({{end}}{{range $i, $output := .Outputs}}{{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap}}{{if lt $i (len $method.Outputs)}}, {{end}}{{end}}error{{if len .Outputs}}){{end}} {
+func (c *{{$serviceName}}) {{.Name}}(ctx context.Context{{range $_, $input := $inputs}}, {{$input.Name}} {{template "type" dict "Type" $input.Type "Optional" $input.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}}{{end}}) {{if len .Outputs}}({{end}}{{range $i, $output := .Outputs}}{{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}}{{if lt $i (len $method.Outputs)}}, {{end}}{{end}}error{{if len .Outputs}}){{end}} {
 	{{- $inputVar := "nil" -}}
 	{{- $outputVar := "nil" -}}
 	{{- if $inputs | len}}
 	{{- $inputVar = "in"}}
 	in := struct {
 	{{- range $i, $input := $inputs}}
-		Arg{{$i}} {{template "type" dict "Type" $input.Type "Optional" $input.Optional "TypeMap" $typeMap}} `json:"{{firstLetterToLower $input.Name}}"`
+		Arg{{$i}} {{template "type" dict "Type" $input.Type "Optional" $input.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}} `json:"{{firstLetterToLower $input.Name}}"`
 	{{- end}}
 	}{ {{- range $i, $input := $inputs}}{{if gt $i 0}}, {{end}}{{$input.Name}}{{end}}}
 	{{- end}}
 	{{- if $outputs | len}}
 	{{- $outputVar = "&out"}}
 	out := struct {
 	{{- range $i, $output := .Outputs}}
-		Ret{{$i}} {{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap}} `json:"{{firstLetterToLower $output.Name}}"`
+		Ret{{$i}} {{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}} `json:"{{firstLetterToLower $output.Name}}"`
 	{{- end}}
 	}{}
 	{{- end}}

_examples/golang-imports/api.gen.go

@@ -0,0 +1,61 @@
+{{- define "imports" -}}
+{{- $types := .Types -}}
+{{- $opts := .Opts -}}
+
+{{- /* Map of import paths. */ -}}
+{{- $stdlibImports := dict -}}
+{{- set $stdlibImports "context" "" -}}
+{{- set $stdlibImports "errors" "" -}}
+{{- set $stdlibImports "encoding/json" "" -}}
+{{- set $stdlibImports "fmt" "" -}}
+{{- set $stdlibImports "io/ioutil" "" -}}
+{{- set $stdlibImports "net/http" "" -}}
+
+{{- if $opts.client}}
+	{{- set $stdlibImports "bytes" "" -}}
+	{{- set $stdlibImports "io" "" -}}
+	{{- set $stdlibImports "net/url" "" -}}
+{{- end -}}
+{{- if $opts.server}}
+	{{- set $stdlibImports "strings" "" -}}
+{{- end -}}
+
+{{- /* Import "time" if there's at least one timestamp. */ -}}
+{{ if eq $opts.importTypesFrom "" }}
+	{{- range $_, $type := $types -}}
+		{{- range $_, $field := $type.Fields -}}
+			{{- if $field.Type -}}
+				{{- if eq $field.Type.Expr "timestamp" -}}
+					{{- set $stdlibImports "time" "" -}}
+				{{- end -}}
+			{{- end -}}
+		{{- end -}}
+	{{- end -}}
+{{- end -}}
+
+{{- /* Print stdlib imports. */ -}}
+{{- range $import, $rename := $stdlibImports }}
+	{{if ne $rename ""}}{{$rename}} {{end}}"{{$import}}"
+{{- end -}}
+
+{{ if ne $opts.importTypesFrom "" }}
+
+	"{{ $opts.importTypesFrom }}"
+{{- else }}
+	{{- /* Print custom type imports. */ -}}
+	{{ $imports := dict }}
+	{{ range $_, $type := $types -}}
+		{{- range $_, $field := $type.Fields -}}
+			{{- range $meta := $field.Meta -}}
+				{{- if exists $meta "go.type.import" -}}
+					{{- set $imports (get $meta "go.type.import") "" -}}
+				{{- end -}}
+			{{- end -}}
+		{{- end -}}
+	{{- end }}
+	{{- range $import, $rename := $imports }}
+	{{if ne $rename ""}}{{$rename}} {{end}}"{{$import}}"
+	{{- end -}}
+{{- end }}
+
+{{- end -}}

client.go.tmpl

@@ -5,8 +5,14 @@
 {{- set $opts "pkg" (default .Opts.pkg "proto") -}}
 {{- set $opts "client" (ternary (in .Opts.client "" "true") true false) -}}
 {{- set $opts "server" (ternary (in .Opts.server "" "true") true false) -}}
+{{- set $opts "importTypesFrom" (default .Opts.importTypesFrom "" ) -}}
 {{- set $opts "legacyErrors" (ternary (in .Opts.legacyErrors "true") true false) -}}
 
+{{- $typePrefix := (last (split "/" $opts.importTypesFrom)) -}}
+{{- if ne $typePrefix "" -}}
+  {{- $typePrefix = (printf "%s." $typePrefix) -}}
+{{- end -}}
+
 {{- /* Print help on -help. */ -}}
 {{- if exists .Opts "help" -}}
   {{- template "help" $opts -}}
@@ -33,7 +39,7 @@
 {{- end -}}
 
 {{- /* Map webrpc core types to Go. */ -}}
-{{- $typeMap := dict }}
+{{- $typeMap := dict -}}
 {{- set $typeMap "null" "struct{}" -}}
 {{- set $typeMap "any" "interface{}" -}}
 {{- set $typeMap "byte" "byte" -}}
@@ -61,17 +67,7 @@
 package {{get $opts "pkg"}}
 
 import (
-	"bytes"
-	"context"
-	"errors"
-	"encoding/json"
-	"fmt"
- 	"io"
-	"io/ioutil"
-	"net/http"
-	"net/url"
-	"strings"
-	"time"
+  {{- template "imports" dict "Types" .Types "Opts" $opts }}
 )
 
 // WebRPC description and code-gen version
@@ -89,19 +85,21 @@ func WebRPCSchemaHash() string {
 	return "{{.SchemaHash}}"
 }
 
-{{ template "types" dict "Services" .Services "Types" .Types "TypeMap" $typeMap }}
+{{ if eq $opts.importTypesFrom "" -}}
+{{ template "types" dict "Services" .Services "Types" .Types "TypeMap" $typeMap "TypePrefix" $typePrefix}}
+{{- end }}
 
 {{- if $opts.server}}
-{{ template "server" dict "Services" .Services "TypeMap" $typeMap }}
+{{ template "server" dict "Services" .Services "TypeMap" $typeMap "TypePrefix" $typePrefix }}
 {{ end -}}
 
 {{- if $opts.client }}
-{{ template "client" dict "Services" .Services "TypeMap" $typeMap }}
+{{ template "client" dict "Services" .Services "TypeMap" $typeMap "TypePrefix" $typePrefix }}
 {{ end -}}
 
 {{ template "helpers" . }}
 
-{{- template "errors" dict "WebrpcErrors" .WebrpcErrors "SchemaErrors" .Errors "Opts" $opts }}
+{{- template "errors" dict "WebrpcErrors" .WebrpcErrors "SchemaErrors" .Errors "Opts" $opts "TypePrefix" $typePrefix}}
 
 {{- if $opts.legacyErrors }}
 {{ template "legacyErrors" . }}

imports.go.tmpl

@@ -1,5 +1,6 @@
 {{define "server"}}
 {{- $typeMap := .TypeMap -}}
+{{- $typePrefix := .TypePrefix -}}
 {{- if .Services }}
 //
 // Server
@@ -14,10 +15,10 @@ type WebRPCServer interface {
 {{ $serviceName := (printf "%sServer" (.Name | firstLetterToLower)) }}
 
 type {{$serviceName}} struct {
-	{{.Name}}
+	{{$typePrefix}}{{.Name}}
 }
 
-func New{{ .Name | firstLetterToUpper }}Server(svc {{.Name}}) WebRPCServer {
+func New{{ .Name | firstLetterToUpper }}Server(svc {{$typePrefix}}{{.Name}}) WebRPCServer {
 	return &{{$serviceName}}{
 		{{.Name}}: svc,
 	}
@@ -71,7 +72,7 @@ func (s *{{$serviceName}}) serve{{ .Name | firstLetterToUpper }}JSON(ctx context
 	{{- if .Inputs|len}}
 	reqContent := struct {
 	{{- range $i, $input := .Inputs}}
-		Arg{{$i}} {{template "type" dict "Type" $input.Type "Optional" $input.Optional "TypeMap" $typeMap}} `json:"{{firstLetterToLower $input.Name}}"`
+		Arg{{$i}} {{template "type" dict "Type" $input.Type "Optional" $input.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}} `json:"{{firstLetterToLower $input.Name}}"`
 	{{- end}}
 	}{}
 
@@ -93,7 +94,7 @@ func (s *{{$serviceName}}) serve{{ .Name | firstLetterToUpper }}JSON(ctx context
 
 	// Call service method
 	{{- range $i, $output := .Outputs}}
-	var ret{{$i}} {{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap}}
+	var ret{{$i}} {{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}}
 	{{- end}}
 	func() {
 		defer func() {
@@ -108,7 +109,7 @@ func (s *{{$serviceName}}) serve{{ .Name | firstLetterToUpper }}JSON(ctx context
 	{{- if .Outputs | len}}
 	respContent := struct {
 	{{- range $i, $output := .Outputs}}
-		Ret{{$i}} {{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap}} `json:"{{firstLetterToLower $output.Name}}"`
+		Ret{{$i}} {{template "type" dict "Type" $output.Type "Optional" $output.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}} `json:"{{firstLetterToLower $output.Name}}"`
 	{{- end}}
 	}{ {{- range $i, $_ := .Outputs}}{{if gt $i 0}}, {{end}}ret{{$i}}{{end}}}
 	{{- end}}

main.go.tmpl

@@ -3,6 +3,7 @@
 {{- $name := .Name -}}
 {{- $fields := .Fields -}}
 {{- $typeMap := .TypeMap -}}
+{{- $typePrefix := .TypePrefix -}}
 
 type {{$name}} struct {
 {{- range $_, $field := $fields -}}
@@ -29,7 +30,7 @@ type {{$name}} struct {
 			{{- end -}}
 		{{- end -}}
 	{{- end }}
-	{{$fieldName}} {{template "type" dict "Type" $field.Type "CustomType" $customType "Optional" $field.Optional "TypeMap" $typeMap}} `{{$jsonTag}}{{if len $structTags}} {{end}}{{join (sort $structTags) " "}}`
+	{{$fieldName}} {{template "type" dict "Type" $field.Type "CustomType" $customType "Optional" $field.Optional "TypeMap" $typeMap "TypePrefix" $typePrefix}} `{{$jsonTag}}{{if len $structTags}} {{end}}{{join (sort $structTags) " "}}`
 {{- end}}
 }
 {{- end }}