Merge branch 'main' into CEC-3796

src/utils/unionIntersect.js

@@ -0,0 +1,16 @@
+export default function unionIntersect(...arrays) {
+  if (arrays.length === 0) return [];
+  if (arrays.length === 1) return arrays[0];
+
+  const result = [];
+  const sets = arrays.slice(1).map(array => new Set(array));
+
+  // TODO: Use a priority queue
+  arrays[0].forEach((value) => {
+    if (sets.every(set => set.has(value))) {
+      result.push(value);
+    }
+  });
+
+  return result;
+}

src/utils/unionIntersect.test.js

@@ -0,0 +1,93 @@
+import unionIntersect from "./unionIntersect";
+
+const tests = [
+  [
+    "merges identical arrays",
+    [
+      [1, 2, 3, 4, 5],
+      [1, 2, 3, 4, 5],
+      [1, 2, 3, 4, 5],
+    ],
+    [1, 2, 3, 4, 5],
+  ],
+  [
+    "merges arrays with smaller initial array",
+    [
+      [1, 2, 4, 5],
+      [1, 2, 3, 4, 5],
+      [1, 2, 3, 4, 5],
+    ],
+    [1, 2, 4, 5],
+  ],
+  [
+    "merges arrays with larger initial array",
+    [
+      [1, 2, 3, 4, 5, 6, 7],
+      [1, 2, 3, 4, 5],
+      [1, 2, 3, 4, 5],
+    ],
+    [1, 2, 3, 4, 5],
+  ],
+  [
+    "merges arrays with empty initial array",
+    [
+      [],
+      [1, 2, 3, 4, 5],
+      [1, 2, 3, 4, 5],
+    ],
+    [],
+  ],
+  [
+    "merges arrays with empty array",
+    [
+      [1, 2, 3, 4, 5],
+      [],
+      [1, 2, 3, 4, 5],
+    ],
+    [],
+  ],
+  [
+    "merges arrays with empty array",
+    [
+      [1, 2, 3, 4, 5],
+      [],
+      [1, 2, 3, 4, 5],
+    ],
+    [],
+  ],
+  [
+    "merges arrays with no overlap",
+    [
+      [1, 2, 3],
+      [4, 5, 6],
+      [7, 8, 9],
+    ],
+    [],
+  ],
+  [
+    "merges arrays with some overlap",
+    [
+      [1, 2, 3, 4, 5, 6],
+      [4, 5, 6, 7, 8, 9],
+      [6, 7, 8, 9, 10, 11, 12],
+    ],
+    [6],
+  ],
+  [
+    "does not support objects",
+    [
+      [{ key: "value" }, { key: "value2" }],
+      [{ key: "value" }, { key: "value3" }],
+      [{ key: "value" }, { key: "value4" }],
+    ],
+    [],
+  ],
+];
+
+describe("unionIntersect", () => {
+  tests.forEach(([desc, arrays, expected]) => {
+    it(desc, () => {
+      expect(unionIntersect(...arrays)).toStrictEqual(expected);
+    });
+  });
+});