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b36237ddcb
Uses the recommended rules apart from complexity/useArrowFunction, which would affect about 1700 lines of code with little benefit right now. This is something that can be addressed over time.
114 lines
3.4 KiB
JavaScript
114 lines
3.4 KiB
JavaScript
// Copyright 2013 Lovell Fuller and others.
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// SPDX-License-Identifier: Apache-2.0
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const assert = require('node:assert');
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const sharp = require('../../');
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const fixtures = require('../fixtures');
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describe('Image channel extraction', function () {
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it('Red channel', function (done) {
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sharp(fixtures.inputJpg)
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.extractChannel('red')
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.resize(320, 240)
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.toBuffer(function (err, data, info) {
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if (err) throw err;
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assert.strictEqual(320, info.width);
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assert.strictEqual(240, info.height);
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fixtures.assertSimilar(fixtures.expected('extract-red.jpg'), data, done);
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});
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});
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it('Green channel', function (done) {
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sharp(fixtures.inputJpg)
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.extractChannel('green')
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.resize(320, 240)
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.toBuffer(function (err, data, info) {
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if (err) throw err;
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assert.strictEqual(320, info.width);
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assert.strictEqual(240, info.height);
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fixtures.assertSimilar(fixtures.expected('extract-green.jpg'), data, done);
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});
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});
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it('Blue channel', function (done) {
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sharp(fixtures.inputJpg)
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.extractChannel('blue')
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.resize(320, 240)
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.toBuffer(function (err, data, info) {
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if (err) throw err;
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assert.strictEqual(320, info.width);
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assert.strictEqual(240, info.height);
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fixtures.assertSimilar(fixtures.expected('extract-blue.jpg'), data, done);
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});
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});
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it('Blue channel by number', function (done) {
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sharp(fixtures.inputJpg)
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.extractChannel(2)
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.resize(320, 240)
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.toBuffer(function (err, data, info) {
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if (err) throw err;
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assert.strictEqual(320, info.width);
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assert.strictEqual(240, info.height);
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fixtures.assertSimilar(fixtures.expected('extract-blue.jpg'), data, done);
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});
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});
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it('With colorspace conversion', async () => {
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const [chroma] = await sharp({ create: { width: 1, height: 1, channels: 3, background: 'red' } })
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.toColourspace('lch')
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.extractChannel(1)
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.toBuffer();
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assert.strictEqual(chroma, 104);
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});
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it('Alpha from 16-bit PNG', function (done) {
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const output = fixtures.path('output.extract-alpha-16bit.png');
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sharp(fixtures.inputPngWithTransparency16bit)
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.resize(16)
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.extractChannel(3)
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.toFile(output, function (err) {
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if (err) throw err;
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fixtures.assertMaxColourDistance(output, fixtures.expected('extract-alpha-16bit.png'));
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done();
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});
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});
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it('Alpha from 2-channel input', function (done) {
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const output = fixtures.path('output.extract-alpha-2-channel.png');
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sharp(fixtures.inputPngWithGreyAlpha)
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.extractChannel('alpha')
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.toFile(output, function (err, info) {
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if (err) throw err;
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assert.strictEqual(1, info.channels);
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fixtures.assertMaxColourDistance(output, fixtures.expected('extract-alpha-2-channel.png'));
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done();
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});
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});
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it('Invalid channel number', function () {
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assert.throws(function () {
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sharp(fixtures.inputJpg)
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.extractChannel(-1);
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});
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});
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it('No arguments', function () {
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assert.throws(function () {
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sharp(fixtures.inputJpg)
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.extractChannel();
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});
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});
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it('Non-existent channel', async () =>
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await assert.rejects(
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() => sharp({ create: { width: 1, height: 1, channels: 3, background: 'red' } })
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.extractChannel(3)
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.toBuffer(),
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/Cannot extract channel 3 from image with channels 0-2/
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)
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);
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});
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