Use entry metadata for resolution presence

facade_resolution_presence_test.go

@@ -0,0 +1,63 @@
+package configkit_test
+
+import (
+	"errors"
+	"testing"
+
+	configkit "gitea.maximumdirect.net/eric/ConfigKit"
+)
+
+func TestFacadeResolutionPresenceUsesDynamicEntryShape(t *testing.T) {
+	t.Parallel()
+
+	type configuration struct {
+		Shape any `yaml:"shape"`
+	}
+	tests := []struct {
+		name       string
+		input      string
+		keyPresent bool
+	}{
+		{name: "mapping key", input: "shape: {'0': input}\n", keyPresent: true},
+		{name: "sequence index", input: "shape: [input]\n", keyPresent: false},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			parsed, err := configkit.ParsePath("/shape/0")
+			if err != nil {
+				t.Fatal(err)
+			}
+			_, err = configkit.Load(configkit.Bytes("dynamic.yml", []byte(test.input)), configkit.Options[configuration]{
+				Definition: configkit.Definition[configuration]{
+					Resolve: func(_ *configuration, resolution *configkit.Resolution) error {
+						check := func(path configkit.Path, want bool) error {
+							info, found := resolution.InputInfo(path)
+							explicit := resolution.IsExplicit(path)
+							if found != want || explicit != want || (found && info.Explicit != explicit) {
+								return errors.New("resolution presence disagrees with dynamic entry shape")
+							}
+							return nil
+						}
+						for _, checkPath := range []struct {
+							path configkit.Path
+							want bool
+						}{
+							{path: configkit.Keys("shape", "0"), want: test.keyPresent},
+							{path: configkit.Keys("shape").Index(0), want: !test.keyPresent},
+							{path: parsed, want: true},
+							{path: configkit.Keys("shape", "missing"), want: false},
+						} {
+							if err := check(checkPath.path, checkPath.want); err != nil {
+								return err
+							}
+						}
+						return nil
+					},
+				},
+			})
+			if err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}