refactor: standardize API error handling (#1635)

backend/internal/httpserver/binding_test.go

@@ -0,0 +1,85 @@
+package httpserver
+
+import (
+	"bytes"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/pocket-id/pocket-id/backend/internal/apperror"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/text/unicode/norm"
+)
+
+func TestBindJSONClassifiesMalformedBody(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	c, _ := gin.CreateTestContext(httptest.NewRecorder())
+	c.Request = httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/", strings.NewReader(`{"name":`))
+	c.Request.Header.Set("Content-Type", "application/json")
+
+	var input struct {
+		Name string `json:"name"`
+	}
+	err := BindJSON(c, &input)
+
+	require.True(t, apperror.IsCode(err, apperror.CodeInvalidRequestBody))
+	require.Contains(t, err.Error(), "unexpected EOF")
+	var appErr *apperror.Error
+	require.ErrorAs(t, err, &appErr)
+	require.NotContains(t, appErr.ClientMessage(), "unexpected end")
+}
+
+func TestBindJSONNormalizesTaggedFieldsRecursively(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	c, _ := gin.CreateTestContext(httptest.NewRecorder())
+	c.Request = httptest.NewRequestWithContext(
+		t.Context(),
+		http.MethodPost,
+		"/",
+		strings.NewReader(`{"name":"Cafe\u0301","email":"user@cafe\u0301.example","items":[{"label":"Re\u0301sume\u0301"}]}`),
+	)
+	c.Request.Header.Set("Content-Type", "application/json")
+
+	type embeddedInput struct {
+		Name string `json:"name" unorm:"nfc"`
+	}
+	type itemInput struct {
+		Label string `json:"label" unorm:"nfc"`
+	}
+	var input struct {
+		embeddedInput
+		Email *string     `json:"email" unorm:"nfc"`
+		Items []itemInput `json:"items"`
+	}
+	err := BindJSON(c, &input)
+
+	require.NoError(t, err)
+	require.Equal(t, norm.NFC.String("Café"), input.Name)
+	require.NotNil(t, input.Email)
+	require.Equal(t, norm.NFC.String("user@café.example"), *input.Email)
+	require.Equal(t, norm.NFC.String("Résumé"), input.Items[0].Label)
+}
+
+func TestFormFileClassifiesMissingField(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	c, _ := gin.CreateTestContext(httptest.NewRecorder())
+	var body bytes.Buffer
+	writer := multipart.NewWriter(&body)
+	require.NoError(t, writer.Close())
+	c.Request = httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/", &body)
+	c.Request.Header.Set("Content-Type", writer.FormDataContentType())
+
+	_, err := FormFile(c, "file")
+
+	require.True(t, apperror.IsCode(err, apperror.CodeValidationFailed))
+	var appErr *apperror.Error
+	require.ErrorAs(t, err, &appErr)
+	require.Equal(t, []apperror.FieldError{{
+		Field:   "file",
+		Code:    "required",
+		Message: "is required",
+	}}, appErr.Fields())
+}