Add selected profile overlays

overlay_test.go

@@ -0,0 +1,78 @@
+package configkit
+
+import (
+	"reflect"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
+)
+
+func TestOverlayDocumentsRecursesMappingsAndReplacesAtomicSubtrees(t *testing.T) {
+	baseRoot := parseCompositionDocument(t, "source-1", `shared:
+  kept: base
+  changed: old
+sequence: [one, two]
+nullable: value
+to_map: scalar
+to_scalar: {child: old}
+`)
+	base, diagnostics := composeDocuments(baseRoot)
+	if len(diagnostics) != 0 {
+		t.Fatal(diagnostics)
+	}
+	overlay := parseCompositionDocument(t, "source-2", `shared:
+  changed: new
+  added: profile
+sequence: []
+nullable: null
+to_map: {child: new}
+to_scalar: scalar
+`)
+	baseBefore := document.Clone(base.root)
+	overlayBefore := document.Clone(overlay)
+
+	result, diagnostics := overlayDocuments(base, overlay)
+	if len(diagnostics) != 0 {
+		t.Fatalf("overlayDocuments() diagnostics = %#v", diagnostics)
+	}
+	checks := []struct {
+		path Path
+		kind document.Kind
+		text string
+	}{
+		{path: Keys("shared", "kept"), kind: document.String, text: "base"},
+		{path: Keys("shared", "changed"), kind: document.String, text: "new"},
+		{path: Keys("shared", "added"), kind: document.String, text: "profile"},
+		{path: Keys("sequence"), kind: document.Sequence},
+		{path: Keys("nullable"), kind: document.Null},
+		{path: Keys("to_map"), kind: document.Mapping},
+		{path: Keys("to_map", "child"), kind: document.String, text: "new"},
+		{path: Keys("to_scalar"), kind: document.String, text: "scalar"},
+	}
+	for _, check := range checks {
+		node, ok := documentAtPath(result.root, check.path)
+		if !ok || node.Kind != check.kind || node.Text != check.text {
+			t.Errorf("node %s = %#v, %v", check.path.String(), node, ok)
+		}
+	}
+	if _, exists := result.origins["/sequence/0"]; exists {
+		t.Fatal("replaced empty sequence retained a stale index origin")
+	}
+	if _, exists := result.origins["/to_scalar/child"]; exists {
+		t.Fatal("parent replacement retained a stale child origin")
+	}
+	shared := result.origins["/shared"]
+	if shared.Layer != LayerProfile || len(shared.Locations) != 2 {
+		t.Fatalf("shared mapping origin = %#v", shared)
+	}
+	if len(result.overlays) != 5 {
+		t.Fatalf("overlay records = %#v, want five replacements", result.overlays)
+	}
+	if !reflect.DeepEqual(base.root, baseBefore) || !reflect.DeepEqual(overlay, overlayBefore) {
+		t.Fatal("overlay mutated an input document")
+	}
+	result.root.Mapping[0].Value.Mapping[0].Value.Text = "changed"
+	if !reflect.DeepEqual(base.root, baseBefore) || !reflect.DeepEqual(overlay, overlayBefore) {
+		t.Fatal("overlay result aliases an input document")
+	}
+}