feat(draw): graph card template — circular node/edge layout (T-321)

graphTemplateHandler lowers a {nodes,edges} payload to SVG: a deterministic circular layout of labelled <circle> nodes with <line> edges, self-contained (own light backdrop + content colors, like a d2 card) and painted by the shared renderer. Display-only (D-78); decoupled from the interactive graph pane (T-323) since a static card only needs a layout->SVG. Honest error on a duplicate id or an edge to an unknown node. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-30 00:00:44 +02:00
parent 64410e8047
commit c167a37ea7
4 changed files with 174 additions and 0 deletions
@@ -0,0 +1,81 @@
+import 'package:clide/src/draw/draw_dispatch.dart';
+import 'package:clide/src/draw/draw_doc.dart';
+import 'package:clide/src/draw/graph_template.dart';
+import 'package:test/test.dart';
+
+void main() {
+  final handler = graphTemplateHandler();
+  DrawingCardDoc doc(Map<String, Object?> fields) => DrawingCardDoc(template: 'graph', fields: {'template': 'graph', ...fields});
+
+  test('lays out nodes as labelled circles and edges as lines', () async {
+    final r = await handler(
+      doc({
+        'nodes': [
+          {'id': 'a', 'label': 'Alpha'},
+          {'id': 'b', 'label': 'Beta'},
+        ],
+        'edges': [
+          {'from': 'a', 'to': 'b'},
+        ],
+      }),
+    );
+    final svg = (r as DrawOk).svg;
+    expect('<circle'.allMatches(svg).length, 2);
+    expect('<line'.allMatches(svg).length, 1);
+    expect(svg, contains('>Alpha<'));
+    expect(svg, contains('>Beta<'));
+  });
+
+  test('a node label defaults to its id', () async {
+    final r = await handler(
+      doc({
+        'nodes': [
+          {'id': 'solo'},
+        ],
+      }),
+    );
+    expect((r as DrawOk).svg, contains('>solo<'));
+  });
+
+  test('empty or missing nodes is an honest error', () async {
+    expect(await handler(doc({'nodes': const []})), isA<DrawErr>());
+    expect(await handler(doc(const {})), isA<DrawErr>());
+  });
+
+  test('a duplicate node id is an error', () async {
+    final r = await handler(
+      doc({
+        'nodes': [
+          {'id': 'x'},
+          {'id': 'x'},
+        ],
+      }),
+    );
+    expect((r as DrawErr).message, contains('duplicate'));
+  });
+
+  test('an edge to an unknown node is an error', () async {
+    final r = await handler(
+      doc({
+        'nodes': [
+          {'id': 'a'},
+        ],
+        'edges': [
+          {'from': 'a', 'to': 'ghost'},
+        ],
+      }),
+    );
+    expect((r as DrawErr).message, contains('ghost'));
+  });
+
+  test('escapes label text', () async {
+    final r = await handler(
+      doc({
+        'nodes': [
+          {'id': 'a', 'label': '<b>&'},
+        ],
+      }),
+    );
+    expect((r as DrawOk).svg, contains('&lt;b&gt;&amp;'));
+  });
+}