dbx/packages/app-tests/imagePreviewViewer.test.ts

49 lines
1.3 KiB
TypeScript

import { strict as assert } from "node:assert";
import test from "node:test";
import {
imagePreviewFitScale,
clampImagePreviewScale,
imagePreviewTransform,
nextImagePreviewScale,
} from "../../apps/desktop/src/lib/imagePreviewViewer.ts";
test("clamps image preview zoom to usable bounds", () => {
assert.equal(clampImagePreviewScale(0.1), 0.2);
assert.equal(clampImagePreviewScale(1.25), 1.25);
assert.equal(clampImagePreviewScale(12), 8);
});
test("zooms in fixed steps from wheel direction", () => {
assert.equal(nextImagePreviewScale(1, "in"), 1.2);
assert.equal(nextImagePreviewScale(1, "out"), 0.8);
assert.equal(nextImagePreviewScale(7.95, "in"), 8);
});
test("builds a stable CSS transform for image previews", () => {
assert.equal(
imagePreviewTransform({ scale: 1.5, offsetX: 12, offsetY: -8 }),
"translate(12px, -8px) scale(1.5)",
);
});
test("calculates fit scale from image and viewport dimensions", () => {
assert.equal(
imagePreviewFitScale({
imageWidth: 2000,
imageHeight: 1000,
viewportWidth: 1000,
viewportHeight: 800,
}),
0.45,
);
assert.equal(
imagePreviewFitScale({
imageWidth: 200,
imageHeight: 100,
viewportWidth: 1000,
viewportHeight: 800,
}),
1,
);
});