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node_modules/@weborigami/async-tree/test/operations/deepMerge.test.js

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+import assert from "node:assert";
+import { describe, test } from "node:test";
+import { DeepObjectTree, Tree } from "../../src/internal.js";
+import mergeDeep from "../../src/operations/deepMerge.js";
+
+describe("mergeDeep", () => {
+  test("can merge deep", async () => {
+    const fixture = mergeDeep(
+      new DeepObjectTree({
+        a: {
+          b: 0, // Will be obscured by `b` below
+          c: {
+            d: 2,
+          },
+        },
+      }),
+      new DeepObjectTree({
+        a: {
+          b: 1,
+          c: {
+            e: 3,
+          },
+          f: 4,
+        },
+      })
+    );
+    assert.deepEqual(await Tree.plain(fixture), {
+      a: {
+        b: 1,
+        c: {
+          d: 2,
+          e: 3,
+        },
+        f: 4,
+      },
+    });
+
+    // Parent of a subvalue is the merged tree
+    const a = await fixture.get("a");
+    assert.equal(a.parent, fixture);
+  });
+});