Initial release of go-telegram

A fully-generated, strongly-typed Go client for the Telegram Bot API.

* 176 methods + 301 types generated from Bot API v10.0
* 1408 auto-generated tests (8 scenarios per method)
* Typed unions throughout — no 'any' in the public surface
* Pluggable HTTP transport and JSON codec (default goccy/go-json)
* Built-in retry middleware honouring Telegram's retry_after
* Generic dispatcher with filters and conversation handlers
* Self-verifying codegen pipeline (regen → audit → emit → run tests)
* 14 example bots covering common patterns

cmd/genapi/types.tmpl

@@ -0,0 +1,126 @@
+// Code generated by cmd/genapi. DO NOT EDIT.
+
+//go:build !ignore_autogenerated
+
+// Package api contains the Telegram Bot API object types and method
+// wrappers, generated from the live documentation by cmd/genapi.
+package api
+
+import (
+	"github.com/goccy/go-json"
+	"fmt"
+	"io"
+)
+
+var _ = io.Discard   // keep import even if no fields use io
+var _ = json.Marshal // keep import for UnmarshalXxx helpers
+var _ = fmt.Errorf   // keep import for UnmarshalXxx helpers
+
+{{range .Types}}
+{{- $td := . -}}
+{{if .OneOf}}
+// {{.Name}} is a union type. The following concrete variants implement
+// it:
+{{range .OneOf}}//   - {{.}}
+{{end}}//
+{{docComment .Doc -}}
+type {{.Name}} interface{ is{{.Name}}() }
+
+{{range .OneOf}}
+// is{{$td.Name}} is the marker method that makes {{.}} implement {{$td.Name}}.
+func (*{{.}}) is{{$td.Name}}() {}
+{{end}}
+{{if hasDiscriminator .Name}}
+// Unmarshal{{.Name}} decodes a {{.Name}} from JSON by inspecting the
+// "{{discriminatorField .Name}}" field and dispatching to the correct concrete type.
+func Unmarshal{{.Name}}(data []byte) ({{.Name}}, error) {
+	var probe struct {
+		V string `json:"{{discriminatorField .Name}}"`
+	}
+	if err := json.Unmarshal(data, &probe); err != nil {
+		return nil, err
+	}
+	var v {{.Name}}
+	switch probe.V {
+{{range $val, $typ := discriminatorMap .Name}}	case {{printf "%q" $val}}:
+		v = &{{$typ}}{}
+{{end}}	default:
+		return nil, fmt.Errorf("{{.Name}}: unknown {{discriminatorField .Name}} %q", probe.V)
+	}
+	if err := json.Unmarshal(data, v); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+{{end}}
+{{if isMaybeInaccessibleMessage .Name}}
+// UnmarshalMaybeInaccessibleMessage decodes a JSON object into the correct
+// MaybeInaccessibleMessage variant. Telegram uses the date field as a
+// discriminator: date == 0 indicates InaccessibleMessage; any other value
+// indicates a real Message.
+func UnmarshalMaybeInaccessibleMessage(data []byte) (MaybeInaccessibleMessage, error) {
+	var probe struct {
+		Date int64 `json:"date"`
+	}
+	if err := json.Unmarshal(data, &probe); err != nil {
+		return nil, fmt.Errorf("MaybeInaccessibleMessage: %w", err)
+	}
+	if probe.Date == 0 {
+		v := &InaccessibleMessage{}
+		if err := json.Unmarshal(data, v); err != nil {
+			return nil, fmt.Errorf("InaccessibleMessage: %w", err)
+		}
+		return v, nil
+	}
+	v := &Message{}
+	if err := json.Unmarshal(data, v); err != nil {
+		return nil, fmt.Errorf("Message: %w", err)
+	}
+	return v, nil
+}
+{{end}}
+{{else}}
+{{docComment .Doc -}}
+type {{.Name}} struct {
+{{range .Fields}}{{docComment .Doc}}{{goField .}}
+{{end}}}
+{{$unionFields := unionFields .}}{{if $unionFields}}
+// UnmarshalJSON decodes {{.Name}} by dispatching union-typed fields
+// ({{range $i, $u := $unionFields}}{{if $i}}, {{end}}{{$u.Field.Name}}{{end}}) through their concrete UnmarshalXxx helpers.
+func (m *{{.Name}}) UnmarshalJSON(data []byte) error {
+	type Alias {{.Name}}
+	aux := &struct {
+		{{range $unionFields}}{{.Field.Name}} json.RawMessage `json:"{{.Field.JSONName}},omitempty"`
+		{{end}}*Alias
+	}{Alias: (*Alias)(m)}
+	if err := json.Unmarshal(data, aux); err != nil {
+		return err
+	}
+	{{range $unionFields}}{{$f := .Field}}{{$u := .UnionName}}
+	if len(aux.{{$f.Name}}) > 0 && string(aux.{{$f.Name}}) != "null" {
+		{{if isArrayUnion $f.Type}}var raws []json.RawMessage
+		if err := json.Unmarshal(aux.{{$f.Name}}, &raws); err != nil {
+			return fmt.Errorf("decoding {{$f.JSONName}}: %w", err)
+		}
+		decoded := make([]{{$u}}, 0, len(raws))
+		for i, r := range raws {
+			v, err := Unmarshal{{$u}}(r)
+			if err != nil {
+				return fmt.Errorf("decoding {{$f.JSONName}}[%d]: %w", i, err)
+			}
+			decoded = append(decoded, v)
+		}
+		m.{{$f.Name}} = decoded
+		{{else}}v, err := Unmarshal{{$u}}(aux.{{$f.Name}})
+		if err != nil {
+			return fmt.Errorf("decoding {{$f.JSONName}}: %w", err)
+		}
+		m.{{$f.Name}} = v
+		{{end}}
+	}
+	{{end}}
+	return nil
+}
+{{end}}
+{{end}}
+{{end}}