From d564cdcae34ccd76b63188c79efe2025fb0c46dd Mon Sep 17 00:00:00 2001
From: Mathias Bergqvist <mthbqv@gmail.com>
Date: Mon, 4 May 2026 21:26:29 +0200
Subject: [PATCH] feat(gitea): typed error mapping from http status

---
 internal/gitea/errors.go      | 34 ++++++++++++++++++++++++++++++++++
 internal/gitea/errors_test.go | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 internal/gitea/errors.go
 create mode 100644 internal/gitea/errors_test.go

diff --git a/internal/gitea/errors.go b/internal/gitea/errors.go
new file mode 100644
index 0000000..f1ed180
--- /dev/null
+++ b/internal/gitea/errors.go
@@ -0,0 +1,34 @@
+package gitea
+
+import (
+	"errors"
+	"fmt"
+)
+
+var (
+	ErrPermissionDenied = errors.New("permission denied")
+	ErrNotFound         = errors.New("not found")
+	ErrConflict         = errors.New("conflict")
+	ErrValidation       = errors.New("validation failed")
+	ErrUpstream         = errors.New("upstream gitea error")
+)
+
+// MapStatus returns nil for 2xx, otherwise a typed error wrapping the response body.
+func MapStatus(status int, body []byte) error {
+	if status >= 200 && status < 300 {
+		return nil
+	}
+	switch {
+	case status == 401, status == 403:
+		return fmt.Errorf("%w: %s", ErrPermissionDenied, body)
+	case status == 404:
+		return fmt.Errorf("%w: %s", ErrNotFound, body)
+	case status == 409:
+		return fmt.Errorf("%w: %s", ErrConflict, body)
+	case status == 422:
+		return fmt.Errorf("%w: %s", ErrValidation, body)
+	case status >= 500:
+		return fmt.Errorf("%w (status %d)", ErrUpstream, status)
+	}
+	return fmt.Errorf("unexpected status %d: %s", status, body)
+}
diff --git a/internal/gitea/errors_test.go b/internal/gitea/errors_test.go
new file mode 100644
index 0000000..9b8a221
--- /dev/null
+++ b/internal/gitea/errors_test.go
@@ -0,0 +1,34 @@
+package gitea_test
+
+import (
+	"errors"
+	"testing"
+
+	"gitea.d-ma.be/mathias/gitea-mcp/internal/gitea"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMapStatus(t *testing.T) {
+	cases := []struct {
+		status int
+		want   error
+	}{
+		{401, gitea.ErrPermissionDenied},
+		{403, gitea.ErrPermissionDenied},
+		{404, gitea.ErrNotFound},
+		{409, gitea.ErrConflict},
+		{422, gitea.ErrValidation},
+		{500, gitea.ErrUpstream},
+		{502, gitea.ErrUpstream},
+		{200, nil},
+		{299, nil},
+	}
+	for _, tc := range cases {
+		got := gitea.MapStatus(tc.status, []byte(`{"message":"x"}`))
+		if tc.want == nil {
+			assert.NoError(t, got)
+		} else {
+			assert.True(t, errors.Is(got, tc.want), "status %d", tc.status)
+		}
+	}
+}