feat(canvas): 交互可读性 - 优化连线、字号与工作条

web/test/canvas-text-scale.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, test } from "bun:test";
+
+import { canvasTextFontSize } from "@/lib/canvas/canvas-text-scale";
+
+describe("canvas text font scaling", () => {
+    test("keeps the configured base size at the default node size", () => {
+        expect(canvasTextFontSize(340, 240, 14)).toBe(14);
+    });
+
+    test("scales proportionally when the node grows in both directions", () => {
+        expect(canvasTextFontSize(680, 480, 14)).toBeCloseTo(28);
+    });
+
+    test("responds when only one dimension changes", () => {
+        expect(canvasTextFontSize(680, 240, 14)).toBeCloseTo(14 * Math.sqrt(2));
+    });
+
+    test("uses metadata font size as the base and clamps extremes", () => {
+        expect(canvasTextFontSize(340, 240, 20)).toBe(20);
+        expect(canvasTextFontSize(1, 1, 2)).toBe(8);
+        expect(canvasTextFontSize(10_000, 10_000, 20)).toBe(72);
+    });
+});