move core tests to tests/ folder

tests/utils.test.ts

@@ -0,0 +1,93 @@
+import {
+  escape,
+  htmlTrim,
+  idGenerator,
+  memoize,
+  debounce,
+  findInTree
+} from "../src/utils";
+
+describe("escape", () => {
+  test("normal strings", () => {
+    const text = "abc";
+    expect(escape(text)).toBe(text);
+  });
+
+  test("special symbols", () => {
+    const text = "<ok>";
+    expect(escape(text)).toBe("&lt;ok&gt;");
+  });
+});
+
+describe("htmlTrim", () => {
+  test("basic use", () => {
+    expect(htmlTrim("abc")).toBe("abc");
+    expect(htmlTrim("  abc")).toBe(" abc");
+    expect(htmlTrim("abc  ")).toBe("abc ");
+    expect(htmlTrim("   abc   ")).toBe(" abc ");
+    expect(htmlTrim("abc\n   ")).toBe("abc ");
+    expect(htmlTrim("\n ")).toBe(" ");
+    expect(htmlTrim(" \n ")).toBe(" ");
+    expect(htmlTrim("  ")).toBe(" ");
+    expect(htmlTrim("")).toBe("");
+  });
+});
+
+describe("idGenerator", () => {
+  test("basic use", () => {
+    let gen = idGenerator();
+    expect(gen()).toBe(1);
+    expect(gen()).toBe(2);
+    expect(gen()).toBe(3);
+  });
+});
+
+describe("memoize", () => {
+  test("return correct value", () => {
+    const f = memoize((a, b) => a + b);
+    expect(f(1, 3)).toBe(4);
+  });
+
+  test("does not recompute if not needed", () => {
+    let nCalls = 0;
+    function origFunction(a: number, b: number): number {
+      nCalls++;
+      return a + b;
+    }
+    const memoized = memoize(origFunction);
+
+    expect(memoized(1, 3)).toBe(4);
+    expect(memoized(1, 3)).toBe(4);
+    expect(nCalls).toBe(1);
+  });
+});
+
+describe("debounce", () => {
+  test("works as expected", () => {
+    jest.useFakeTimers();
+    let n = 0;
+    let f = debounce(() => n++, 100);
+    expect(n).toBe(0);
+    f();
+    expect(n).toBe(0);
+    f();
+    expect(n).toBe(0);
+    jest.advanceTimersByTime(90);
+    expect(n).toBe(0);
+    jest.advanceTimersByTime(20);
+    expect(n).toBe(1);
+  });
+});
+
+describe("findInTree", () => {
+  test("can find stuff in tree", () => {
+    let tree = {
+      id: 1,
+      children: [{ id: 2, children: [] }, { id: 3, key: "hello", children: [] }]
+    };
+    const match1 = findInTree(tree, t => t.id === 3);
+    expect((<any>match1).key).toBe("hello");
+    const match2 = findInTree(tree, t => t.id === 4);
+    expect(match2).toBe(null);
+  });
+});