fix: preserve existing Inertia props in ShareErrors()

pkg/form/form.go

@@ -3,6 +3,7 @@ package form
 import (
 	"github.com/labstack/echo/v4"
 	"github.com/occult/pagode/pkg/context"
+	"github.com/romsar/gonertia/v2"
 )
 
 // Form represents a form that can be submitted and validated.
@@ -30,6 +31,9 @@ type Form interface {
 
 	// GetFieldErrors returns the validation errors for a given struct field.
 	GetFieldErrors(fieldName string) []string
+
+	// GetErrors returns all validation errors keyed by field name.
+	GetErrors() map[string][]string
 }
 
 // Get gets a form from the context or initializes a new copy if one is not set.
@@ -51,3 +55,22 @@ func Clear(ctx echo.Context) {
 func Submit(ctx echo.Context, form Form) error {
 	return form.Submit(ctx, form)
 }
+
+// ShareErrors shares form validation errors as Inertia props.
+// It merges the errors with existing Inertia props to preserve
+// previously set shared data like auth, flash, etc.
+func ShareErrors(ctx echo.Context, form Form) {
+	errors := form.GetErrors()
+	if len(errors) == 0 {
+		return
+	}
+
+	existingProps := gonertia.PropsFromContext(ctx.Request().Context())
+	if existingProps == nil {
+		existingProps = make(map[string]any)
+	}
+	existingProps["errors"] = errors
+
+	newCtx := gonertia.SetProps(ctx.Request().Context(), existingProps)
+	ctx.SetRequest(ctx.Request().WithContext(newCtx))
+}

pkg/form/form_test.go

@@ -1,11 +1,13 @@
 package form
 
 import (
+	"net/http/httptest"
 	"testing"
 
 	"github.com/labstack/echo/v4"
 	"github.com/occult/pagode/pkg/context"
 	"github.com/occult/pagode/pkg/tests"
+	"github.com/romsar/gonertia/v2"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -61,3 +63,109 @@ func TestGetClear(t *testing.T) {
 		assert.Empty(t, got.Name)
 	})
 }
+
+func TestShareErrorsPreservesExistingProps(t *testing.T) {
+	e := echo.New()
+	req := httptest.NewRequest("POST", "/test", nil)
+	rec := httptest.NewRecorder()
+	ctx := e.NewContext(req, rec)
+
+	// Set up existing Inertia props
+	existingProps := map[string]any{
+		"auth": map[string]any{
+			"user": map[string]any{"name": "Test User"},
+		},
+		"flash": map[string]any{
+			"success": []string{"Welcome!"},
+		},
+	}
+	newReqCtx := gonertia.SetProps(req.Context(), existingProps)
+	ctx.SetRequest(req.WithContext(newReqCtx))
+
+	// Create a form with errors
+	form := &mockForm{}
+	form.SetFieldError("Email", "Email is required")
+	form.SetFieldError("Password", "Password is required")
+
+	// Share errors
+	ShareErrors(ctx, form)
+
+	// Get props from context
+	props := gonertia.PropsFromContext(ctx.Request().Context())
+	require.NotNil(t, props)
+
+	// Verify existing props are preserved
+	auth, ok := props["auth"].(map[string]any)
+	require.True(t, ok, "auth prop should exist")
+	user, ok := auth["user"].(map[string]any)
+	require.True(t, ok, "auth.user should exist")
+	assert.Equal(t, "Test User", user["name"])
+
+	flash, ok := props["flash"].(map[string]any)
+	require.True(t, ok, "flash prop should exist")
+	success, ok := flash["success"].([]string)
+	require.True(t, ok, "flash.success should exist")
+	assert.Equal(t, []string{"Welcome!"}, success)
+
+	// Verify errors are added
+	errors, ok := props["errors"].(map[string][]string)
+	require.True(t, ok, "errors prop should exist")
+	assert.Equal(t, []string{"Email is required"}, errors["Email"])
+	assert.Equal(t, []string{"Password is required"}, errors["Password"])
+}
+
+func TestShareErrorsWorksWithNoExistingProps(t *testing.T) {
+	e := echo.New()
+	req := httptest.NewRequest("POST", "/test", nil)
+	rec := httptest.NewRecorder()
+	ctx := e.NewContext(req, rec)
+
+	// Create a form with errors
+	form := &mockForm{}
+	form.SetFieldError("Name", "Name is required")
+
+	// Share errors (no existing props)
+	ShareErrors(ctx, form)
+
+	// Get props from context
+	props := gonertia.PropsFromContext(ctx.Request().Context())
+	require.NotNil(t, props)
+
+	// Verify errors are added
+	errors, ok := props["errors"].(map[string][]string)
+	require.True(t, ok, "errors prop should exist")
+	assert.Equal(t, []string{"Name is required"}, errors["Name"])
+}
+
+func TestShareErrorsNoOpWhenNoErrors(t *testing.T) {
+	e := echo.New()
+	req := httptest.NewRequest("POST", "/test", nil)
+	rec := httptest.NewRecorder()
+	ctx := e.NewContext(req, rec)
+
+	// Set up existing Inertia props
+	existingProps := map[string]any{
+		"auth": map[string]any{
+			"user": "test",
+		},
+	}
+	newReqCtx := gonertia.SetProps(req.Context(), existingProps)
+	ctx.SetRequest(req.WithContext(newReqCtx))
+
+	// Create a form with NO errors
+	form := &mockForm{}
+
+	// Share errors (should be no-op)
+	ShareErrors(ctx, form)
+
+	// Get props from context
+	props := gonertia.PropsFromContext(ctx.Request().Context())
+	require.NotNil(t, props)
+
+	// Verify existing props are untouched
+	assert.Equal(t, "test", props["auth"].(map[string]any)["user"])
+
+	// Verify no errors key was added
+	_, hasErrors := props["errors"]
+	assert.False(t, hasErrors, "errors prop should not exist when there are no errors")
+}

pkg/form/submission.go

@@ -73,6 +73,13 @@ func (f *Submission) GetFieldErrors(fieldName string) []string {
 	return f.errors[fieldName]
 }
 
+func (f *Submission) GetErrors() map[string][]string {
+	if f.errors == nil {
+		return make(map[string][]string)
+	}
+	return f.errors
+}
+
 // setErrorMessages sets errors messages on the submission for all fields that failed validation.
 func (f *Submission) setErrorMessages(err error) {
 	// Only this is supported right now