Add the notes dock

app/src/store/dockWidth.test.ts

@@ -0,0 +1,31 @@
+import { describe, it, expect } from "vitest";
+import {
+  clampDockWidth,
+  NOTES_DOCK_MIN_WIDTH,
+  NOTES_DOCK_MAX_WIDTH,
+  NOTES_DOCK_DEFAULT_WIDTH,
+} from "./appState";
+
+describe("clampDockWidth", () => {
+  it("keeps a sensible width", () => {
+    expect(clampDockWidth(400)).toBe(400);
+  });
+
+  it("refuses to squeeze the dock into uselessness", () => {
+    expect(clampDockWidth(10)).toBe(NOTES_DOCK_MIN_WIDTH);
+  });
+
+  it("refuses to squeeze the terminal into uselessness", () => {
+    expect(clampDockWidth(5000)).toBe(NOTES_DOCK_MAX_WIDTH);
+  });
+
+  it("falls back for a stored value that is not a number", () => {
+    // localStorage holds strings and can carry anything a previous version,
+    // a hand edit, or a different screen left behind.
+    expect(clampDockWidth(Number("banana"))).toBe(NOTES_DOCK_DEFAULT_WIDTH);
+  });
+
+  it("rounds, because a fractional px width blurs the border", () => {
+    expect(clampDockWidth(400.6)).toBe(401);
+  });
+});