Experimental: Embed webrpc errors source code

Author: VojtechVitek

errors.go

@@ -0,0 +1,55 @@
+package gospeak
+
+import (
+	"errors"
+	"fmt"
+)
+
+// Deprecated: This type may be removed in the future.
+type WebRPCError struct {
+	Name       string `json:"error"`
+	Code       int    `json:"code"`
+	Message    string `json:"msg"`
+	Cause      string `json:"cause,omitempty"`
+	HTTPStatus int    `json:"status"`
+	cause      error
+}
+
+var _ error = WebRPCError{}
+
+func (e WebRPCError) Error() string {
+	if e.cause != nil {
+		return fmt.Sprintf("%s %d: %s: %v", e.Name, e.Code, e.Message, e.cause)
+	}
+	return fmt.Sprintf("%s %d: %s", e.Name, e.Code, e.Message)
+}
+
+func (e WebRPCError) Is(target error) bool {
+	if rpcErr, ok := target.(WebRPCError); ok {
+		return rpcErr.Code == e.Code
+	}
+	return errors.Is(e.cause, target)
+}
+
+func (e WebRPCError) Unwrap() error {
+	return e.cause
+}
+
+func ErrorWithCause(rpcErr WebRPCError, cause error) WebRPCError {
+	err := rpcErr
+	err.cause = cause
+	err.Cause = cause.Error()
+	return err
+}
+
+// Webrpc errors
+var (
+	ErrWebrpcEndpoint      = WebRPCError{Code: 0, Name: "WebrpcEndpoint", Message: "endpoint error", HTTPStatus: 400}
+	ErrWebrpcRequestFailed = WebRPCError{Code: -1, Name: "WebrpcRequestFailed", Message: "request failed", HTTPStatus: 400}
+	ErrWebrpcBadRoute      = WebRPCError{Code: -2, Name: "WebrpcBadRoute", Message: "bad route", HTTPStatus: 404}
+	ErrWebrpcBadMethod     = WebRPCError{Code: -3, Name: "WebrpcBadMethod", Message: "bad method", HTTPStatus: 405}
+	ErrWebrpcBadRequest    = WebRPCError{Code: -4, Name: "WebrpcBadRequest", Message: "bad request", HTTPStatus: 400}
+	ErrWebrpcBadResponse   = WebRPCError{Code: -5, Name: "WebrpcBadResponse", Message: "bad response", HTTPStatus: 500}
+	ErrWebrpcServerPanic   = WebRPCError{Code: -6, Name: "WebrpcServerPanic", Message: "server panic", HTTPStatus: 500}
+	ErrWebrpcInternalError = WebRPCError{Code: -7, Name: "WebrpcInternalError", Message: "internal error", HTTPStatus: 500}
+)

parser.go

@@ -1,6 +1,7 @@
 package gospeak
 
 import (
+	_ "embed"
 	"fmt"
 	"go/ast"
 	"go/token"
@@ -14,6 +15,9 @@ import (
 	"golang.org/x/tools/go/packages"
 )
 
+//go:embed errors.go
+var webrpcErrorsSourceCode string
+
 type Target struct {
 	Schema        *schema.WebRPCSchema
 	Generator     string
@@ -43,16 +47,21 @@ func Parse(filePath string) ([]*Target, error) {
 		Overlay: map[string][]byte{},
 	}
 
+	packageLine := fmt.Sprintf("package %s", filepath.Base(dir))
+
 	// Make the parser ignore all previously generated Go files to avoid the
 	// chicken-egg problem (ie. syntax errors in file we're currently generating).
 	_ = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
 		if err == nil && !info.IsDir() && strings.HasSuffix(path, ".gen.go") {
 			// Overlay the source with an empty package name.
-			cfg.Overlay[path] = []byte(fmt.Sprintf("package %s", filepath.Base(dir)))
+			cfg.Overlay[path] = []byte(packageLine)
 		}
 		return nil
 	})
 
+	errorsSourceCode := strings.Replace(webrpcErrorsSourceCode, "package gospeak", packageLine, 1)
+	cfg.Overlay[dir+"/webrpcErrors.gen.go"] = []byte(errorsSourceCode)
+
 	pkgs, err := packages.Load(cfg, dir)
 	if err != nil {
 		return nil, fmt.Errorf("failed to load Go packages from %q: %w", dir, err)