signal-desktop/ts/test-electron/util/canvasToBlob_test.ts
2021-08-05 20:17:05 -04:00

46 lines
1.2 KiB
TypeScript

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import { assert } from 'chai';
import { IMAGE_JPEG, IMAGE_PNG } from '../../types/MIME';
import { sniffImageMimeType } from '../../util/sniffImageMimeType';
import { canvasToBlob } from '../../util/canvasToBlob';
describe('canvasToBlob', () => {
let canvas: HTMLCanvasElement;
beforeEach(() => {
canvas = document.createElement('canvas');
canvas.width = 100;
canvas.height = 200;
const context = canvas.getContext('2d');
if (!context) {
throw new Error('Test setup error: cannot get canvas rendering context');
}
context.fillStyle = '#ff9900';
context.fillRect(10, 10, 20, 20);
});
it('converts a canvas to an Blob, JPEG by default', async () => {
const result = await canvasToBlob(canvas);
assert.strictEqual(
sniffImageMimeType(await result.arrayBuffer()),
IMAGE_JPEG
);
// These are just smoke tests.
assert.instanceOf(result, Blob);
assert.isAtLeast(result.size, 50);
});
it('can convert a canvas to a PNG Blob', async () => {
const result = await canvasToBlob(canvas, IMAGE_PNG);
assert.strictEqual(
sniffImageMimeType(await result.arrayBuffer()),
IMAGE_PNG
);
});
});