LibTest+Spreadsheet: Add some basic spreadsheet runtime behaviour tests

As there's a somewhat active development going on, let's keep the
expected behaviour under tests to make sure nothing blows up :^)

Userland/Applications/Spreadsheet/Tests/free-functions.js

@@ -0,0 +1,166 @@
+describe("Basic functions", () => {
+    const workbook = createWorkbook();
+    const sheet = createSheet(workbook, "Sheet 1");
+    sheet.makeCurrent();
+
+    sheet.setCell("A", 0, "0");
+    sheet.setCell("A", 1, "1");
+    sheet.setCell("A", 2, "2");
+
+    test("select", () => {
+        expect(select).toBeDefined();
+        expect(select(true, 1, 2)).toBe(1);
+        expect(select(false, 1, 2)).toBe(2);
+    });
+
+    test("choose", () => {
+        expect(choose).toBeDefined();
+        expect(choose(0, 1, 2, 3)).toBe(1);
+        expect(choose(1, 1, 2, 3)).toBe(2);
+        expect(choose(3, 1, 2, 3)).toBeUndefined();
+        expect(choose(-1, 1, 2, 3)).toBeUndefined();
+    });
+
+    test("now", () => {
+        expect(now).toBeDefined();
+        expect(now()).toBeInstanceOf(Date);
+    });
+
+    test("randRange", () => {
+        expect(randRange).toBeDefined();
+    });
+
+    test("integer", () => {
+        expect(integer).toBeDefined();
+        expect(integer("0")).toEqual(0);
+        expect(integer("32")).toEqual(32);
+    });
+
+    test("sheet", () => {
+        expect(globalThis.sheet).toBeDefined();
+        expect(globalThis.sheet("Sheet 1")).toBe(sheet);
+        expect(globalThis.sheet("Not a sheet")).toBeUndefined();
+    });
+
+    test("reduce", () => {
+        expect(reduce).toBeDefined();
+        expect(reduce(acc => acc + 1, 0, [1, 2, 3, 4])).toEqual(4);
+        expect(reduce(acc => acc + 1, 0, [])).toEqual(0);
+    });
+
+    test("numericReduce", () => {
+        expect(numericReduce).toBeDefined();
+        expect(numericReduce(acc => acc + 1, 0, [1, 2, 3, 4])).toEqual(4);
+        expect(numericReduce(acc => acc + 1, 0, [])).toEqual(0);
+    });
+
+    test("numericResolve", () => {
+        expect(numericResolve).toBeDefined();
+        expect(numericResolve(["A0", "A1", "A2"])).toEqual([0, 1, 2]);
+        expect(numericResolve([])).toEqual([]);
+    });
+
+    test("resolve", () => {
+        expect(resolve).toBeDefined();
+        expect(resolve(["A0", "A1", "A2"])).toEqual(["0", "1", "2"]);
+        expect(resolve([])).toEqual([]);
+    });
+});
+
+describe("Statistics", () => {
+    const workbook = createWorkbook();
+    const sheet = createSheet(workbook, "Sheet 1");
+    sheet.makeCurrent();
+
+    for (let i = 0; i < 10; ++i) sheet.setCell("A", i, `${i}`);
+
+    test("sum", () => {
+        expect(sum).toBeDefined();
+        expect(sum(R`A0:A9`)).toEqual(45);
+    });
+
+    test("sumIf", () => {
+        expect(sumIf).toBeDefined();
+        expect(sumIf(x => !Number.isNaN(x), R`A0:A10`)).toEqual(45);
+    });
+
+    test("count", () => {
+        expect(count).toBeDefined();
+        expect(count(R`A0:A9`)).toEqual(10);
+    });
+
+    test("countIf", () => {
+        expect(countIf).toBeDefined();
+        expect(countIf(x => x, R`A0:A10`)).toEqual(10);
+    });
+
+    test("average", () => {
+        expect(average).toBeDefined();
+        expect(average(R`A0:A9`)).toEqual(4.5);
+    });
+
+    test("averageIf", () => {
+        expect(averageIf).toBeDefined();
+        expect(averageIf(x => !Number.isNaN(x), R`A0:A10`)).toEqual(4.5);
+    });
+
+    test("median", () => {
+        expect(median).toBeDefined();
+        expect(median(R`A0:A9`)).toEqual(4.5);
+        expect(median(R`A0:A2`)).toEqual(1);
+    });
+
+    test("variance", () => {
+        expect(variance).toBeDefined();
+        expect(variance(R`A0:A0`)).toEqual(0);
+        expect(variance(R`A0:A9`)).toEqual(82.5);
+    });
+
+    test("mode", () => {
+        expect(mode).toBeDefined();
+        expect(mode(R`A0:A0`.union(R`A0:A0`).union(R`A1:A9`))).toEqual(0);
+    });
+
+    test("stddev", () => {
+        expect(stddev).toBeDefined();
+        expect(stddev(R`A0:A0`)).toEqual(0);
+        expect(stddev(R`A0:A9`)).toEqual(Math.sqrt(82.5));
+    });
+});
+
+describe("Lookup", () => {
+    const workbook = createWorkbook();
+    const sheet = createSheet(workbook, "Sheet 1");
+    sheet.makeCurrent();
+
+    for (let i = 0; i < 10; ++i) {
+        sheet.setCell("A", i, `${i}`);
+        sheet.setCell("B", i, `B${i}`);
+    }
+
+    sheet.focusCell("A", 0);
+
+    test("row", () => {
+        expect(row()).toEqual(0);
+    });
+
+    test("column", () => {
+        expect(column()).toEqual("A");
+    });
+
+    test("lookup", () => {
+        expect(lookup).toBeDefined();
+        // Note: String ordering.
+        expect(lookup("2", R`A0:A9`, R`B0:B9`)).toEqual("B2");
+        expect(lookup("20", R`A0:A9`, R`B0:B9`)).toBeUndefined();
+        expect(lookup("80", R`A0:A9`, R`B0:B9`, undefined, "nextlargest")).toEqual("B9");
+    });
+
+    test("reflookup", () => {
+        expect(reflookup).toBeDefined();
+        // Note: String ordering.
+        expect(reflookup("2", R`A0:A9`, R`B0:B9`).name).toEqual("B2");
+        expect(reflookup("20", R`A0:A9`, R`B0:B9`)).toEqual(here());
+        expect(reflookup("80", R`A0:A9`, R`B0:B9`, undefined, "nextlargest").name).toEqual("B9");
+    });
+});