Support multiple forms on a single page.

Author: mikestefanello

pkg/form/form.go

@@ -9,8 +9,8 @@ import (
 type Form interface {
 	// Submit marks the form as submitted, stores a pointer to it in the context, binds the request
 	// values to the struct fields, and validates the input based on the struct tags.
-	// Returns a validator.ValidationErrors if the form values were not valid.
-	// Returns an echo.HTTPError if the request failed to process.
+	// Returns a validator.ValidationErrors, if the form values were not valid, or an echo.HTTPError,
+	// if the request failed to process.
 	Submit(c echo.Context, form any) error
 
 	// IsSubmitted returns true if the form was submitted.
@@ -35,7 +35,9 @@ type Form interface {
 // Get gets a form from the context or initializes a new copy if one is not set.
 func Get[T any](ctx echo.Context) *T {
 	if v := ctx.Get(context.FormKey); v != nil {
-		return v.(*T)
+		if form, ok := v.(*T); ok {
+			return form
+		}
 	}
 	var v T
 	return &v

pkg/form/form_test.go

@@ -36,7 +36,7 @@ func TestGetClear(t *testing.T) {
 	}
 
 	t.Run("get empty context", func(t *testing.T) {
-		// Empty context, still return a form
+		// Empty context, still return a form.
 		ctx, _ := tests.NewContext(e, "/")
 		form := Get[example](ctx)
 		assert.NotNil(t, form)
@@ -49,12 +49,16 @@ func TestGetClear(t *testing.T) {
 		ctx, _ := tests.NewContext(e, "/")
 		ctx.Set(context.FormKey, &form)
 
-		// Get again and expect the values were stored
+		// Get again and expect the values were stored.
 		got := Get[example](ctx)
 		require.NotNil(t, got)
-		assert.Equal(t, "test", form.Name)
+		assert.Equal(t, "test", got.Name)
 
-		// Clear
+		// Attempt getting a different type to ensure there's no panic.
+		ret := Get[int](ctx)
+		require.NotNil(t, ret)
+
+		// Clear.
 		Clear(ctx)
 		got = Get[example](ctx)
 		require.NotNil(t, got)