node/test/parallel/test-stream2-set-encoding.js

'use strict';
const common = require('../common');
const assert = require('assert');
const R = require('_stream_readable');

class TestReader extends R {
  constructor(n, opts) {
    super(opts);
    this.pos = 0;
    this.len = n || 100;
  }

  _read(n) {
    setTimeout(() => {
      if (this.pos >= this.len) {
        // double push(null) to test eos handling
        this.push(null);
        return this.push(null);
      }

      n = Math.min(n, this.len - this.pos);
      if (n <= 0) {
        // double push(null) to test eos handling
        this.push(null);
        return this.push(null);
      }

      this.pos += n;
      const ret = Buffer.alloc(n, 'a');

      return this.push(ret);
    }, 1);
  }
}

{
  // Verify utf8 encoding
  const tr = new TestReader(100);
  tr.setEncoding('utf8');
  const out = [];
  const expect =
    [ 'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(10)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}


{
  // Verify hex encoding
  const tr = new TestReader(100);
  tr.setEncoding('hex');
  const out = [];
  const expect =
    [ '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(10)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}

{
  // Verify hex encoding with read(13)
  const tr = new TestReader(100);
  tr.setEncoding('hex');
  const out = [];
  const expect =
    [ '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '16161' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(13)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}

{
  // Verify base64 encoding
  const tr = new TestReader(100);
  tr.setEncoding('base64');
  const out = [];
  const expect =
    [ 'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYQ==' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(10)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}

{
  // Verify utf8 encoding
  const tr = new TestReader(100, { encoding: 'utf8' });
  const out = [];
  const expect =
    [ 'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa',
      'aaaaaaaaaa' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(10)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}


{
  // Verify hex encoding
  const tr = new TestReader(100, { encoding: 'hex' });
  const out = [];
  const expect =
    [ '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161',
      '6161616161' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(10)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}

{
  // Verify hex encoding with read(13)
  const tr = new TestReader(100, { encoding: 'hex' });
  const out = [];
  const expect =
    [ '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '1616161616161',
      '6161616161616',
      '16161' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(13)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}

{
  // Verify base64 encoding
  const tr = new TestReader(100, { encoding: 'base64' });
  const out = [];
  const expect =
    [ 'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYWFhYWFh',
      'YWFhYWFhYW',
      'FhYQ==' ];

  tr.on('readable', function flow() {
    let chunk;
    while (null !== (chunk = tr.read(10)))
      out.push(chunk);
  });

  tr.on('end', common.mustCall(function() {
    assert.deepStrictEqual(out, expect);
  }));
}

{
  // Verify chaining behavior
  const tr = new TestReader(100);
  assert.deepStrictEqual(tr.setEncoding('utf8'), tr);
}