nodejs/test/parallel/test-stream-preprocess.js

61 lines
1.9 KiB
JavaScript

'use strict';
const common = require('../common');
const assert = require('assert');
const fs = require('fs');
const rl = require('readline');
const fixtures = require('../common/fixtures');
const BOM = '\uFEFF';
// Get the data using a non-stream way to compare with the streamed data.
const modelData = fixtures.readSync('file-to-read-without-bom.txt', 'utf8');
const modelDataFirstCharacter = modelData[0];
// Detect the number of forthcoming 'line' events for mustCall() 'expected' arg.
const lineCount = modelData.match(/\n/g).length;
// Ensure both without-bom and with-bom test files are textwise equal.
assert.strictEqual(fixtures.readSync('file-to-read-with-bom.txt', 'utf8'),
`${BOM}${modelData}`
);
// An unjustified BOM stripping with a non-BOM character unshifted to a stream.
const inputWithoutBOM =
fs.createReadStream(fixtures.path('file-to-read-without-bom.txt'), 'utf8');
inputWithoutBOM.once('readable', common.mustCall(() => {
const maybeBOM = inputWithoutBOM.read(1);
assert.strictEqual(maybeBOM, modelDataFirstCharacter);
assert.notStrictEqual(maybeBOM, BOM);
inputWithoutBOM.unshift(maybeBOM);
let streamedData = '';
rl.createInterface({
input: inputWithoutBOM,
}).on('line', common.mustCall((line) => {
streamedData += `${line}\n`;
}, lineCount)).on('close', common.mustCall(() => {
assert.strictEqual(streamedData, modelData);
}));
}));
// A justified BOM stripping.
const inputWithBOM =
fs.createReadStream(fixtures.path('file-to-read-with-bom.txt'), 'utf8');
inputWithBOM.once('readable', common.mustCall(() => {
const maybeBOM = inputWithBOM.read(1);
assert.strictEqual(maybeBOM, BOM);
let streamedData = '';
rl.createInterface({
input: inputWithBOM,
}).on('line', common.mustCall((line) => {
streamedData += `${line}\n`;
}, lineCount)).on('close', common.mustCall(() => {
assert.strictEqual(streamedData, modelData);
}));
}));