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

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+import assert from "node:assert";
+import { describe, test } from "node:test";
+import { DeepObjectTree, ObjectTree, Tree } from "../../src/internal.js";
+import cache from "../../src/operations/cache.js";
+
+describe("cache", () => {
+  test("caches reads of values from one tree into another", async () => {
+    const objectCache = new ObjectTree({});
+    const fixture = cache(
+      new DeepObjectTree({
+        a: 1,
+        b: 2,
+        c: 3,
+        more: {
+          d: 4,
+        },
+      }),
+      objectCache
+    );
+
+    const keys = [...(await fixture.keys())];
+    assert.deepEqual(keys, ["a", "b", "c", "more/"]);
+
+    assert.equal(await objectCache.get("a"), undefined);
+    assert.equal(await fixture.get("a"), 1);
+    assert.equal(await objectCache.get("a"), 1); // Now in cache
+
+    assert.equal(await objectCache.get("b"), undefined);
+    assert.equal(await fixture.get("b"), 2);
+    assert.equal(await objectCache.get("b"), 2);
+
+    assert.equal(await objectCache.get("more"), undefined);
+    const more = await fixture.get("more");
+    assert.deepEqual([...(await more.keys())], ["d"]);
+    assert.equal(await more.get("d"), 4);
+    const moreCache = await objectCache.get("more");
+    assert.equal(await moreCache.get("d"), 4);
+  });
+
+  test("if a cache filter is supplied, it only caches values whose keys match the filter", async () => {
+    const objectCache = new ObjectTree({});
+    const fixture = cache(
+      Tree.from({
+        "a.txt": "a",
+        "b.txt": "b",
+      }),
+      objectCache,
+      Tree.from({
+        "a.txt": true,
+      })
+    );
+
+    // Access some values to populate the cache.
+    assert.equal(await fixture.get("a.txt"), "a");
+    assert.equal(await fixture.get("b.txt"), "b");
+
+    // The a.txt value should be cached because it matches the filter.
+    assert.equal(await objectCache.get("a.txt"), "a");
+
+    // The b.txt value should not be cached because it does not match the filter.
+    assert.equal(await objectCache.get("b.txt"), undefined);
+  });
+});