easysync_tests.js

/**
 * I found this tests in the old Etherpad and used it to test if the Changeset library can be run on node.js.
 * It has no use for ep-lite, but I thought I keep it cause it may help someone to understand the Changeset library
 * https://github.com/ether/pad/blob/master/infrastructure/ace/www/easysync2_tests.js
 */

/*
 * Copyright 2009 Google Inc., 2011 Peter 'Pita' Martischka (Primary Technology Ltd)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

var CommonCode = require('./utils/common_code');
var Changeset = CommonCode.require("/Changeset");
var AttributePoolFactory = CommonCode.require("/AttributePoolFactory");

function random() {
  this.nextInt = function (maxValue) {
    return Math.floor(Math.random() * maxValue);
  }

  this.nextDouble = function (maxValue) {
    return Math.random();
  }
}

function runTests() {

  function print(str) {
    console.log(str);
  }

  function assert(code, optMsg) {
    if (!eval(code)) throw new Error("FALSE: " + (optMsg || code));
  }

  function literal(v) {
    if ((typeof v) == "string") {
      return '"' + v.replace(/[\\\"]/g, '\\$1').replace(/\n/g, '\\n') + '"';
    } else
    return JSON.stringify(v);
  }

  function assertEqualArrays(a, b) {
    assert("JSON.stringify(" + literal(a) + ") == JSON.stringify(" + literal(b) + ")");
  }

  function assertEqualStrings(a, b) {
    assert(literal(a) + " == " + literal(b));
  }

  function throughIterator(opsStr) {
    var iter = Changeset.opIterator(opsStr);
    var assem = Changeset.opAssembler();
    while (iter.hasNext()) {
      assem.append(iter.next());
    }
    return assem.toString();
  }

  function throughSmartAssembler(opsStr) {
    var iter = Changeset.opIterator(opsStr);
    var assem = Changeset.smartOpAssembler();
    while (iter.hasNext()) {
      assem.append(iter.next());
    }
    assem.endDocument();
    return assem.toString();
  }

  (function () {
    print("> throughIterator");
    var x = '-c*3*4+6|3=az*asdf0*1*2*3+1=1-1+1*0+1=1-1+1|c=c-1';
    assert("throughIterator(" + literal(x) + ") == " + literal(x));
  })();

  (function () {
    print("> throughSmartAssembler");
    var x = '-c*3*4+6|3=az*asdf0*1*2*3+1=1-1+1*0+1=1-1+1|c=c-1';
    assert("throughSmartAssembler(" + literal(x) + ") == " + literal(x));
  })();

  function applyMutations(mu, arrayOfArrays) {
    arrayOfArrays.forEach(function (a) {
      var result = mu[a[0]].apply(mu, a.slice(1));
      if (a[0] == 'remove' && a[3]) {
        assertEqualStrings(a[3], result);
      }
    });
  }

  function mutationsToChangeset(oldLen, arrayOfArrays) {
    var assem = Changeset.smartOpAssembler();
    var op = Changeset.newOp();
    var bank = Changeset.stringAssembler();
    var oldPos = 0;
    var newLen = 0;
    arrayOfArrays.forEach(function (a) {
      if (a[0] == 'skip') {
        op.opcode = '=';
        op.chars = a[1];
        op.lines = (a[2] || 0);
        assem.append(op);
        oldPos += op.chars;
        newLen += op.chars;
      } else if (a[0] == 'remove') {
        op.opcode = '-';
        op.chars = a[1];
        op.lines = (a[2] || 0);
        assem.append(op);
        oldPos += op.chars;
      } else if (a[0] == 'insert') {
        op.opcode = '+';
        bank.append(a[1]);
        op.chars = a[1].length;
        op.lines = (a[2] || 0);
        assem.append(op);
        newLen += op.chars;
      }
    });
    newLen += oldLen - oldPos;
    assem.endDocument();
    return Changeset.pack(oldLen, newLen, assem.toString(), bank.toString());
  }

  function runMutationTest(testId, origLines, muts, correct) {
    print("> runMutationTest#" + testId);
    var lines = origLines.slice();
    var mu = Changeset.textLinesMutator(lines);
    applyMutations(mu, muts);
    mu.close();
    assertEqualArrays(correct, lines);

    var inText = origLines.join('');
    var cs = mutationsToChangeset(inText.length, muts);
    lines = origLines.slice();
    Changeset.mutateTextLines(cs, lines);
    assertEqualArrays(correct, lines);

    var correctText = correct.join('');
    //print(literal(cs));
    var outText = Changeset.applyToText(cs, inText);
    assertEqualStrings(correctText, outText);
  }

  runMutationTest(1, ["apple\n", "banana\n", "cabbage\n", "duffle\n", "eggplant\n"], [
    ['remove', 1, 0, "a"],
    ['insert', "tu"],
    ['remove', 1, 0, "p"],
    ['skip', 4, 1],
    ['skip', 7, 1],
    ['insert', "cream\npie\n", 2],
    ['skip', 2],
    ['insert', "bot"],
    ['insert', "\n", 1],
    ['insert', "bu"],
    ['skip', 3],
    ['remove', 3, 1, "ge\n"],
    ['remove', 6, 0, "duffle"]
  ], ["tuple\n", "banana\n", "cream\n", "pie\n", "cabot\n", "bubba\n", "eggplant\n"]);

  runMutationTest(2, ["apple\n", "banana\n", "cabbage\n", "duffle\n", "eggplant\n"], [
    ['remove', 1, 0, "a"],
    ['remove', 1, 0, "p"],
    ['insert', "tu"],
    ['skip', 11, 2],
    ['insert', "cream\npie\n", 2],
    ['skip', 2],
    ['insert', "bot"],
    ['insert', "\n", 1],
    ['insert', "bu"],
    ['skip', 3],
    ['remove', 3, 1, "ge\n"],
    ['remove', 6, 0, "duffle"]
  ], ["tuple\n", "banana\n", "cream\n", "pie\n", "cabot\n", "bubba\n", "eggplant\n"]);

  runMutationTest(3, ["apple\n", "banana\n", "cabbage\n", "duffle\n", "eggplant\n"], [
    ['remove', 6, 1, "apple\n"],
    ['skip', 15, 2],
    ['skip', 6],
    ['remove', 1, 1, "\n"],
    ['remove', 8, 0, "eggplant"],
    ['skip', 1, 1]
  ], ["banana\n", "cabbage\n", "duffle\n"]);

  runMutationTest(4, ["15\n"], [
    ['skip', 1],
    ['insert', "\n2\n3\n4\n", 4],
    ['skip', 2, 1]
  ], ["1\n", "2\n", "3\n", "4\n", "5\n"]);

  runMutationTest(5, ["1\n", "2\n", "3\n", "4\n", "5\n"], [
    ['skip', 1],
    ['remove', 7, 4, "\n2\n3\n4\n"],
    ['skip', 2, 1]
  ], ["15\n"]);

  runMutationTest(6, ["123\n", "abc\n", "def\n", "ghi\n", "xyz\n"], [
    ['insert', "0"],
    ['skip', 4, 1],
    ['skip', 4, 1],
    ['remove', 8, 2, "def\nghi\n"],
    ['skip', 4, 1]
  ], ["0123\n", "abc\n", "xyz\n"]);

  runMutationTest(7, ["apple\n", "banana\n", "cabbage\n", "duffle\n", "eggplant\n"], [
    ['remove', 6, 1, "apple\n"],
    ['skip', 15, 2, true],
    ['skip', 6, 0, true],
    ['remove', 1, 1, "\n"],
    ['remove', 8, 0, "eggplant"],
    ['skip', 1, 1, true]
  ], ["banana\n", "cabbage\n", "duffle\n"]);

  function poolOrArray(attribs) {
    if (attribs.getAttrib) {
      return attribs; // it's already an attrib pool
    } else {
      // assume it's an array of attrib strings to be split and added
      var p = AttributePoolFactory.createAttributePool();
      attribs.forEach(function (kv) {
        p.putAttrib(kv.split(','));
      });
      return p;
    }
  }

  function runApplyToAttributionTest(testId, attribs, cs, inAttr, outCorrect) {
    print("> applyToAttribution#" + testId);
    var p = poolOrArray(attribs);
    var result = Changeset.applyToAttribution(
    Changeset.checkRep(cs), inAttr, p);
    assertEqualStrings(outCorrect, result);
  }

  // turn c<b>a</b>ctus\n into a<b>c</b>tusabcd\n
  runApplyToAttributionTest(1, ['bold,', 'bold,true'], "Z:7>3-1*0=1*1=1=3+4$abcd", "+1*1+1|1+5", "+1*1+1|1+8");

  // turn "david\ngreenspan\n" into "<b>david\ngreen</b>\n"
  runApplyToAttributionTest(2, ['bold,', 'bold,true'], "Z:g<4*1|1=6*1=5-4$", "|2+g", "*1|1+6*1+5|1+1");

  (function () {
    print("> mutatorHasMore");
    var lines = ["1\n", "2\n", "3\n", "4\n"];
    var mu;

    mu = Changeset.textLinesMutator(lines);
    assert(mu.hasMore() + ' == true');
    mu.skip(8, 4);
    assert(mu.hasMore() + ' == false');
    mu.close();
    assert(mu.hasMore() + ' == false');

    // still 1,2,3,4
    mu = Changeset.textLinesMutator(lines);
    assert(mu.hasMore() + ' == true');
    mu.remove(2, 1);
    assert(mu.hasMore() + ' == true');
    mu.skip(2, 1);
    assert(mu.hasMore() + ' == true');
    mu.skip(2, 1);
    assert(mu.hasMore() + ' == true');
    mu.skip(2, 1);
    assert(mu.hasMore() + ' == false');
    mu.insert("5\n", 1);
    assert(mu.hasMore() + ' == false');
    mu.close();
    assert(mu.hasMore() + ' == false');

    // 2,3,4,5 now
    mu = Changeset.textLinesMutator(lines);
    assert(mu.hasMore() + ' == true');
    mu.remove(6, 3);
    assert(mu.hasMore() + ' == true');
    mu.remove(2, 1);
    assert(mu.hasMore() + ' == false');
    mu.insert("hello\n", 1);
    assert(mu.hasMore() + ' == false');
    mu.close();
    assert(mu.hasMore() + ' == false');

  })();

  function runMutateAttributionTest(testId, attribs, cs, alines, outCorrect) {
    print("> runMutateAttributionTest#" + testId);
    var p = poolOrArray(attribs);
    var alines2 = Array.prototype.slice.call(alines);
    var result = Changeset.mutateAttributionLines(
    Changeset.checkRep(cs), alines2, p);
    assertEqualArrays(outCorrect, alines2);

    print("> runMutateAttributionTest#" + testId + ".applyToAttribution");

    function removeQuestionMarks(a) {
      return a.replace(/\?/g, '');
    }
    var inMerged = Changeset.joinAttributionLines(alines.map(removeQuestionMarks));
    var correctMerged = Changeset.joinAttributionLines(outCorrect.map(removeQuestionMarks));
    var mergedResult = Changeset.applyToAttribution(cs, inMerged, p);
    assertEqualStrings(correctMerged, mergedResult);
  }

  // turn 123\n 456\n 789\n into 123\n 4<b>5</b>6\n 789\n
  runMutateAttributionTest(1, ["bold,true"], "Z:c>0|1=4=1*0=1$", ["|1+4", "|1+4", "|1+4"], ["|1+4", "+1*0+1|1+2", "|1+4"]);

  // make a document bold
  runMutateAttributionTest(2, ["bold,true"], "Z:c>0*0|3=c$", ["|1+4", "|1+4", "|1+4"], ["*0|1+4", "*0|1+4", "*0|1+4"]);

  // clear bold on document
  runMutateAttributionTest(3, ["bold,", "bold,true"], "Z:c>0*0|3=c$", ["*1+1+1*1+1|1+1", "+1*1+1|1+2", "*1+1+1*1+1|1+1"], ["|1+4", "|1+4", "|1+4"]);

  // add a character on line 3 of a document with 5 blank lines, and make sure
  // the optimization that skips purely-kept lines is working; if any attribution string
  // with a '?' is parsed it will cause an error.
  runMutateAttributionTest(4, ['foo,bar', 'line,1', 'line,2', 'line,3', 'line,4', 'line,5'], "Z:5>1|2=2+1$x", ["?*1|1+1", "?*2|1+1", "*3|1+1", "?*4|1+1", "?*5|1+1"], ["?*1|1+1", "?*2|1+1", "+1*3|1+1", "?*4|1+1", "?*5|1+1"]);

  var testPoolWithChars = (function () {
    var p = AttributePoolFactory.createAttributePool();
    p.putAttrib(['char', 'newline']);
    for (var i = 1; i < 36; i++) {
      p.putAttrib(['char', Changeset.numToString(i)]);
    }
    p.putAttrib(['char', '']);
    return p;
  })();

  // based on runMutationTest#1
  runMutateAttributionTest(5, testPoolWithChars, "Z:11>7-2*t+1*u+1|2=b|2+a=2*b+1*o+1*t+1*0|1+1*b+1*u+1=3|1-3-6$" + "tucream\npie\nbot\nbu", ["*a+1*p+2*l+1*e+1*0|1+1", "*b+1*a+1*n+1*a+1*n+1*a+1*0|1+1", "*c+1*a+1*b+2*a+1*g+1*e+1*0|1+1", "*d+1*u+1*f+2*l+1*e+1*0|1+1", "*e+1*g+2*p+1*l+1*a+1*n+1*t+1*0|1+1"], ["*t+1*u+1*p+1*l+1*e+1*0|1+1", "*b+1*a+1*n+1*a+1*n+1*a+1*0|1+1", "|1+6", "|1+4", "*c+1*a+1*b+1*o+1*t+1*0|1+1", "*b+1*u+1*b+2*a+1*0|1+1", "*e+1*g+2*p+1*l+1*a+1*n+1*t+1*0|1+1"]);

  // based on runMutationTest#3
  runMutateAttributionTest(6, testPoolWithChars, "Z:11<f|1-6|2=f=6|1-1-8$", ["*a|1+6", "*b|1+7", "*c|1+8", "*d|1+7", "*e|1+9"], ["*b|1+7", "*c|1+8", "*d+6*e|1+1"]);

  // based on runMutationTest#4
  runMutateAttributionTest(7, testPoolWithChars, "Z:3>7=1|4+7$\n2\n3\n4\n", ["*1+1*5|1+2"], ["*1+1|1+1", "|1+2", "|1+2", "|1+2", "*5|1+2"]);

  // based on runMutationTest#5
  runMutateAttributionTest(8, testPoolWithChars, "Z:a<7=1|4-7$", ["*1|1+2", "*2|1+2", "*3|1+2", "*4|1+2", "*5|1+2"], ["*1+1*5|1+2"]);

  // based on runMutationTest#6
  runMutateAttributionTest(9, testPoolWithChars, "Z:k<7*0+1*10|2=8|2-8$0", ["*1+1*2+1*3+1|1+1", "*a+1*b+1*c+1|1+1", "*d+1*e+1*f+1|1+1", "*g+1*h+1*i+1|1+1", "?*x+1*y+1*z+1|1+1"], ["*0+1|1+4", "|1+4", "?*x+1*y+1*z+1|1+1"]);

  runMutateAttributionTest(10, testPoolWithChars, "Z:6>4=1+1=1+1|1=1+1=1*0+1$abcd", ["|1+3", "|1+3"], ["|1+5", "+2*0+1|1+2"]);


  runMutateAttributionTest(11, testPoolWithChars, "Z:s>1|1=4=6|1+1$\n", ["*0|1+4", "*0|1+8", "*0+5|1+1", "*0|1+1", "*0|1+5", "*0|1+1", "*0|1+1", "*0|1+1", "|1+1"], ["*0|1+4", "*0+6|1+1", "*0|1+2", "*0+5|1+1", "*0|1+1", "*0|1+5", "*0|1+1", "*0|1+1", "*0|1+1", "|1+1"]);

  function randomInlineString(len, rand) {
    var assem = Changeset.stringAssembler();
    for (var i = 0; i < len; i++) {
      assem.append(String.fromCharCode(rand.nextInt(26) + 97));
    }
    return assem.toString();
  }

  function randomMultiline(approxMaxLines, approxMaxCols, rand) {
    var numParts = rand.nextInt(approxMaxLines * 2) + 1;
    var txt = Changeset.stringAssembler();
    txt.append(rand.nextInt(2) ? '\n' : '');
    for (var i = 0; i < numParts; i++) {
      if ((i % 2) == 0) {
        if (rand.nextInt(10)) {
          txt.append(randomInlineString(rand.nextInt(approxMaxCols) + 1, rand));
        } else {
          txt.append('\n');
        }
      } else {
        txt.append('\n');
      }
    }
    return txt.toString();
  }

  function randomStringOperation(numCharsLeft, rand) {
    var result;
    switch (rand.nextInt(9)) {
    case 0:
      {
        // insert char
        result = {
          insert: randomInlineString(1, rand)
        };
        break;
      }
    case 1:
      {
        // delete char
        result = {
          remove: 1
        };
        break;
      }
    case 2:
      {
        // skip char
        result = {
          skip: 1
        };
        break;
      }
    case 3:
      {
        // insert small
        result = {
          insert: randomInlineString(rand.nextInt(4) + 1, rand)
        };
        break;
      }
    case 4:
      {
        // delete small
        result = {
          remove: rand.nextInt(4) + 1
        };
        break;
      }
    case 5:
      {
        // skip small
        result = {
          skip: rand.nextInt(4) + 1
        };
        break;
      }
    case 6:
      {
        // insert multiline;
        result = {
          insert: randomMultiline(5, 20, rand)
        };
        break;
      }
    case 7:
      {
        // delete multiline
        result = {
          remove: Math.round(numCharsLeft * rand.nextDouble() * rand.nextDouble())
        };
        break;
      }
    case 8:
      {
        // skip multiline
        result = {
          skip: Math.round(numCharsLeft * rand.nextDouble() * rand.nextDouble())
        };
        break;
      }
    case 9:
      {
        // delete to end
        result = {
          remove: numCharsLeft
        };
        break;
      }
    case 10:
      {
        // skip to end
        result = {
          skip: numCharsLeft
        };
        break;
      }
    }
    var maxOrig = numCharsLeft - 1;
    if ('remove' in result) {
      result.remove = Math.min(result.remove, maxOrig);
    } else if ('skip' in result) {
      result.skip = Math.min(result.skip, maxOrig);
    }
    return result;
  }

  function randomTwoPropAttribs(opcode, rand) {
    // assumes attrib pool like ['apple,','apple,true','banana,','banana,true']
    if (opcode == '-' || rand.nextInt(3)) {
      return '';
    } else if (rand.nextInt(3)) {
      if (opcode == '+' || rand.nextInt(2)) {
        return '*' + Changeset.numToString(rand.nextInt(2) * 2 + 1);
      } else {
        return '*' + Changeset.numToString(rand.nextInt(2) * 2);
      }
    } else {
      if (opcode == '+' || rand.nextInt(4) == 0) {
        return '*1*3';
      } else {
        return ['*0*2', '*0*3', '*1*2'][rand.nextInt(3)];
      }
    }
  }

  function randomTestChangeset(origText, rand, withAttribs) {
    var charBank = Changeset.stringAssembler();
    var textLeft = origText; // always keep final newline
    var outTextAssem = Changeset.stringAssembler();
    var opAssem = Changeset.smartOpAssembler();
    var oldLen = origText.length;

    var nextOp = Changeset.newOp();

    function appendMultilineOp(opcode, txt) {
      nextOp.opcode = opcode;
      if (withAttribs) {
        nextOp.attribs = randomTwoPropAttribs(opcode, rand);
      }
      txt.replace(/\n|[^\n]+/g, function (t) {
        if (t == '\n') {
          nextOp.chars = 1;
          nextOp.lines = 1;
          opAssem.append(nextOp);
        } else {
          nextOp.chars = t.length;
          nextOp.lines = 0;
          opAssem.append(nextOp);
        }
        return '';
      });
    }

    function doOp() {
      var o = randomStringOperation(textLeft.length, rand);
      if (o.insert) {
        var txt = o.insert;
        charBank.append(txt);
        outTextAssem.append(txt);
        appendMultilineOp('+', txt);
      } else if (o.skip) {
        var txt = textLeft.substring(0, o.skip);
        textLeft = textLeft.substring(o.skip);
        outTextAssem.append(txt);
        appendMultilineOp('=', txt);
      } else if (o.remove) {
        var txt = textLeft.substring(0, o.remove);
        textLeft = textLeft.substring(o.remove);
        appendMultilineOp('-', txt);
      }
    }

    while (textLeft.length > 1) doOp();
    for (var i = 0; i < 5; i++) doOp(); // do some more (only insertions will happen)
    var outText = outTextAssem.toString() + '\n';
    opAssem.endDocument();
    var cs = Changeset.pack(oldLen, outText.length, opAssem.toString(), charBank.toString());
    Changeset.checkRep(cs);
    return [cs, outText];
  }

  function testCompose(randomSeed) {
    var rand = new random();
    print("> testCompose#" + randomSeed);

    var p = AttributePoolFactory.createAttributePool();

    var startText = randomMultiline(10, 20, rand) + '\n';

    var x1 = randomTestChangeset(startText, rand);
    var change1 = x1[0];
    var text1 = x1[1];

    var x2 = randomTestChangeset(text1, rand);
    var change2 = x2[0];
    var text2 = x2[1];

    var x3 = randomTestChangeset(text2, rand);
    var change3 = x3[0];
    var text3 = x3[1];

    //print(literal(Changeset.toBaseTen(startText)));
    //print(literal(Changeset.toBaseTen(change1)));
    //print(literal(Changeset.toBaseTen(change2)));
    var change12 = Changeset.checkRep(Changeset.compose(change1, change2, p));
    var change23 = Changeset.checkRep(Changeset.compose(change2, change3, p));
    var change123 = Changeset.checkRep(Changeset.compose(change12, change3, p));
    var change123a = Changeset.checkRep(Changeset.compose(change1, change23, p));
    assertEqualStrings(change123, change123a);

    assertEqualStrings(text2, Changeset.applyToText(change12, startText));
    assertEqualStrings(text3, Changeset.applyToText(change23, text1));
    assertEqualStrings(text3, Changeset.applyToText(change123, startText));
  }

  for (var i = 0; i < 30; i++) testCompose(i);

  (function simpleComposeAttributesTest() {
    print("> simpleComposeAttributesTest");
    var p = AttributePoolFactory.createAttributePool();
    p.putAttrib(['bold', '']);
    p.putAttrib(['bold', 'true']);
    var cs1 = Changeset.checkRep("Z:2>1*1+1*1=1$x");
    var cs2 = Changeset.checkRep("Z:3>0*0|1=3$");
    var cs12 = Changeset.checkRep(Changeset.compose(cs1, cs2, p));
    assertEqualStrings("Z:2>1+1*0|1=2$x", cs12);
  })();

  (function followAttributesTest() {
    var p = AttributePoolFactory.createAttributePool();
    p.putAttrib(['x', '']);
    p.putAttrib(['x', 'abc']);
    p.putAttrib(['x', 'def']);
    p.putAttrib(['y', '']);
    p.putAttrib(['y', 'abc']);
    p.putAttrib(['y', 'def']);

    function testFollow(a, b, afb, bfa, merge) {
      assertEqualStrings(afb, Changeset.followAttributes(a, b, p));
      assertEqualStrings(bfa, Changeset.followAttributes(b, a, p));
      assertEqualStrings(merge, Changeset.composeAttributes(a, afb, true, p));
      assertEqualStrings(merge, Changeset.composeAttributes(b, bfa, true, p));
    }

    testFollow('', '', '', '', '');
    testFollow('*0', '', '', '*0', '*0');
    testFollow('*0', '*0', '', '', '*0');
    testFollow('*0', '*1', '', '*0', '*0');
    testFollow('*1', '*2', '', '*1', '*1');
    testFollow('*0*1', '', '', '*0*1', '*0*1');
    testFollow('*0*4', '*2*3', '*3', '*0', '*0*3');
    testFollow('*0*4', '*2', '', '*0*4', '*0*4');
  })();

  function testFollow(randomSeed) {
    var rand = new random();
    print("> testFollow#" + randomSeed);

    var p = AttributePoolFactory.createAttributePool();

    var startText = randomMultiline(10, 20, rand) + '\n';

    var cs1 = randomTestChangeset(startText, rand)[0];
    var cs2 = randomTestChangeset(startText, rand)[0];

    var afb = Changeset.checkRep(Changeset.follow(cs1, cs2, false, p));
    var bfa = Changeset.checkRep(Changeset.follow(cs2, cs1, true, p));

    var merge1 = Changeset.checkRep(Changeset.compose(cs1, afb));
    var merge2 = Changeset.checkRep(Changeset.compose(cs2, bfa));

    assertEqualStrings(merge1, merge2);
  }

  for (var i = 0; i < 30; i++) testFollow(i);

  function testSplitJoinAttributionLines(randomSeed) {
    var rand = new random();
    print("> testSplitJoinAttributionLines#" + randomSeed);

    var doc = randomMultiline(10, 20, rand) + '\n';

    function stringToOps(str) {
      var assem = Changeset.mergingOpAssembler();
      var o = Changeset.newOp('+');
      o.chars = 1;
      for (var i = 0; i < str.length; i++) {
        var c = str.charAt(i);
        o.lines = (c == '\n' ? 1 : 0);
        o.attribs = (c == 'a' || c == 'b' ? '*' + c : '');
        assem.append(o);
      }
      return assem.toString();
    }

    var theJoined = stringToOps(doc);
    var theSplit = doc.match(/[^\n]*\n/g).map(stringToOps);

    assertEqualArrays(theSplit, Changeset.splitAttributionLines(theJoined, doc));
    assertEqualStrings(theJoined, Changeset.joinAttributionLines(theSplit));
  }

  for (var i = 0; i < 10; i++) testSplitJoinAttributionLines(i);

  (function testMoveOpsToNewPool() {
    print("> testMoveOpsToNewPool");

    var pool1 = AttributePoolFactory.createAttributePool();
    var pool2 = AttributePoolFactory.createAttributePool();

    pool1.putAttrib(['baz', 'qux']);
    pool1.putAttrib(['foo', 'bar']);

    pool2.putAttrib(['foo', 'bar']);

    assertEqualStrings(Changeset.moveOpsToNewPool('Z:1>2*1+1*0+1$ab', pool1, pool2), 'Z:1>2*0+1*1+1$ab');
    assertEqualStrings(Changeset.moveOpsToNewPool('*1+1*0+1', pool1, pool2), '*0+1*1+1');
  })();


  (function testMakeSplice() {
    print("> testMakeSplice");

    var t = "a\nb\nc\n";
    var t2 = Changeset.applyToText(Changeset.makeSplice(t, 5, 0, "def"), t);
    assertEqualStrings("a\nb\ncdef\n", t2);

  })();

  (function testToSplices() {
    print("> testToSplices");

    var cs = Changeset.checkRep('Z:z>9*0=1=4-3+9=1|1-4-4+1*0+a$123456789abcdefghijk');
    var correctSplices = [
      [5, 8, "123456789"],
      [9, 17, "abcdefghijk"]
    ];
    assertEqualArrays(correctSplices, Changeset.toSplices(cs));
  })();

  function testCharacterRangeFollow(testId, cs, oldRange, insertionsAfter, correctNewRange) {
    print("> testCharacterRangeFollow#" + testId);

    var cs = Changeset.checkRep(cs);
    assertEqualArrays(correctNewRange, Changeset.characterRangeFollow(cs, oldRange[0], oldRange[1], insertionsAfter));

  }

  testCharacterRangeFollow(1, 'Z:z>9*0=1=4-3+9=1|1-4-4+1*0+a$123456789abcdefghijk', [7, 10], false, [14, 15]);
  testCharacterRangeFollow(2, "Z:bc<6|x=b4|2-6$", [400, 407], false, [400, 401]);
  testCharacterRangeFollow(3, "Z:4>0-3+3$abc", [0, 3], false, [3, 3]);
  testCharacterRangeFollow(4, "Z:4>0-3+3$abc", [0, 3], true, [0, 0]);
  testCharacterRangeFollow(5, "Z:5>1+1=1-3+3$abcd", [1, 4], false, [5, 5]);
  testCharacterRangeFollow(6, "Z:5>1+1=1-3+3$abcd", [1, 4], true, [2, 2]);
  testCharacterRangeFollow(7, "Z:5>1+1=1-3+3$abcd", [0, 6], false, [1, 7]);
  testCharacterRangeFollow(8, "Z:5>1+1=1-3+3$abcd", [0, 3], false, [1, 2]);
  testCharacterRangeFollow(9, "Z:5>1+1=1-3+3$abcd", [2, 5], false, [5, 6]);
  testCharacterRangeFollow(10, "Z:2>1+1$a", [0, 0], false, [1, 1]);
  testCharacterRangeFollow(11, "Z:2>1+1$a", [0, 0], true, [0, 0]);

  (function testOpAttributeValue() {
    print("> testOpAttributeValue");

    var p = AttributePoolFactory.createAttributePool();
    p.putAttrib(['name', 'david']);
    p.putAttrib(['color', 'green']);

    assertEqualStrings("david", Changeset.opAttributeValue(Changeset.stringOp('*0*1+1'), 'name', p));
    assertEqualStrings("david", Changeset.opAttributeValue(Changeset.stringOp('*0+1'), 'name', p));
    assertEqualStrings("", Changeset.opAttributeValue(Changeset.stringOp('*1+1'), 'name', p));
    assertEqualStrings("", Changeset.opAttributeValue(Changeset.stringOp('+1'), 'name', p));
    assertEqualStrings("green", Changeset.opAttributeValue(Changeset.stringOp('*0*1+1'), 'color', p));
    assertEqualStrings("green", Changeset.opAttributeValue(Changeset.stringOp('*1+1'), 'color', p));
    assertEqualStrings("", Changeset.opAttributeValue(Changeset.stringOp('*0+1'), 'color', p));
    assertEqualStrings("", Changeset.opAttributeValue(Changeset.stringOp('+1'), 'color', p));
  })();

  function testAppendATextToAssembler(testId, atext, correctOps) {
    print("> testAppendATextToAssembler#" + testId);

    var assem = Changeset.smartOpAssembler();
    Changeset.appendATextToAssembler(atext, assem);
    assertEqualStrings(correctOps, assem.toString());
  }

  testAppendATextToAssembler(1, {
    text: "\n",
    attribs: "|1+1"
  }, "");
  testAppendATextToAssembler(2, {
    text: "\n\n",
    attribs: "|2+2"
  }, "|1+1");
  testAppendATextToAssembler(3, {
    text: "\n\n",
    attribs: "*x|2+2"
  }, "*x|1+1");
  testAppendATextToAssembler(4, {
    text: "\n\n",
    attribs: "*x|1+1|1+1"
  }, "*x|1+1");
  testAppendATextToAssembler(5, {
    text: "foo\n",
    attribs: "|1+4"
  }, "+3");
  testAppendATextToAssembler(6, {
    text: "\nfoo\n",
    attribs: "|2+5"
  }, "|1+1+3");
  testAppendATextToAssembler(7, {
    text: "\nfoo\n",
    attribs: "*x|2+5"
  }, "*x|1+1*x+3");
  testAppendATextToAssembler(8, {
    text: "\n\n\nfoo\n",
    attribs: "|2+2*x|2+5"
  }, "|2+2*x|1+1*x+3");

  function testMakeAttribsString(testId, pool, opcode, attribs, correctString) {
    print("> testMakeAttribsString#" + testId);

    var p = poolOrArray(pool);
    var str = Changeset.makeAttribsString(opcode, attribs, p);
    assertEqualStrings(correctString, str);
  }

  testMakeAttribsString(1, ['bold,'], '+', [
    ['bold', '']
  ], '');
  testMakeAttribsString(2, ['abc,def', 'bold,'], '=', [
    ['bold', '']
  ], '*1');
  testMakeAttribsString(3, ['abc,def', 'bold,true'], '+', [
    ['abc', 'def'],
    ['bold', 'true']
  ], '*0*1');
  testMakeAttribsString(4, ['abc,def', 'bold,true'], '+', [
    ['bold', 'true'],
    ['abc', 'def']
  ], '*0*1');

  function testSubattribution(testId, astr, start, end, correctOutput) {
    print("> testSubattribution#" + testId);

    var str = Changeset.subattribution(astr, start, end);
    assertEqualStrings(correctOutput, str);
  }

  testSubattribution(1, "+1", 0, 0, "");
  testSubattribution(2, "+1", 0, 1, "+1");
  testSubattribution(3, "+1", 0, undefined, "+1");
  testSubattribution(4, "|1+1", 0, 0, "");
  testSubattribution(5, "|1+1", 0, 1, "|1+1");
  testSubattribution(6, "|1+1", 0, undefined, "|1+1");
  testSubattribution(7, "*0+1", 0, 0, "");
  testSubattribution(8, "*0+1", 0, 1, "*0+1");
  testSubattribution(9, "*0+1", 0, undefined, "*0+1");
  testSubattribution(10, "*0|1+1", 0, 0, "");
  testSubattribution(11, "*0|1+1", 0, 1, "*0|1+1");
  testSubattribution(12, "*0|1+1", 0, undefined, "*0|1+1");
  testSubattribution(13, "*0+2+1*1+3", 0, 1, "*0+1");
  testSubattribution(14, "*0+2+1*1+3", 0, 2, "*0+2");
  testSubattribution(15, "*0+2+1*1+3", 0, 3, "*0+2+1");
  testSubattribution(16, "*0+2+1*1+3", 0, 4, "*0+2+1*1+1");
  testSubattribution(17, "*0+2+1*1+3", 0, 5, "*0+2+1*1+2");
  testSubattribution(18, "*0+2+1*1+3", 0, 6, "*0+2+1*1+3");
  testSubattribution(19, "*0+2+1*1+3", 0, 7, "*0+2+1*1+3");
  testSubattribution(20, "*0+2+1*1+3", 0, undefined, "*0+2+1*1+3");
  testSubattribution(21, "*0+2+1*1+3", 1, undefined, "*0+1+1*1+3");
  testSubattribution(22, "*0+2+1*1+3", 2, undefined, "+1*1+3");
  testSubattribution(23, "*0+2+1*1+3", 3, undefined, "*1+3");
  testSubattribution(24, "*0+2+1*1+3", 4, undefined, "*1+2");
  testSubattribution(25, "*0+2+1*1+3", 5, undefined, "*1+1");
  testSubattribution(26, "*0+2+1*1+3", 6, undefined, "");
  testSubattribution(27, "*0+2+1*1|1+3", 0, 1, "*0+1");
  testSubattribution(28, "*0+2+1*1|1+3", 0, 2, "*0+2");
  testSubattribution(29, "*0+2+1*1|1+3", 0, 3, "*0+2+1");
  testSubattribution(30, "*0+2+1*1|1+3", 0, 4, "*0+2+1*1+1");
  testSubattribution(31, "*0+2+1*1|1+3", 0, 5, "*0+2+1*1+2");
  testSubattribution(32, "*0+2+1*1|1+3", 0, 6, "*0+2+1*1|1+3");
  testSubattribution(33, "*0+2+1*1|1+3", 0, 7, "*0+2+1*1|1+3");
  testSubattribution(34, "*0+2+1*1|1+3", 0, undefined, "*0+2+1*1|1+3");
  testSubattribution(35, "*0+2+1*1|1+3", 1, undefined, "*0+1+1*1|1+3");
  testSubattribution(36, "*0+2+1*1|1+3", 2, undefined, "+1*1|1+3");
  testSubattribution(37, "*0+2+1*1|1+3", 3, undefined, "*1|1+3");
  testSubattribution(38, "*0+2+1*1|1+3", 4, undefined, "*1|1+2");
  testSubattribution(39, "*0+2+1*1|1+3", 5, undefined, "*1|1+1");
  testSubattribution(40, "*0+2+1*1|1+3", 1, 5, "*0+1+1*1+2");
  testSubattribution(41, "*0+2+1*1|1+3", 2, 6, "+1*1|1+3");
  testSubattribution(42, "*0+2+1*1+3", 2, 6, "+1*1+3");

  function testFilterAttribNumbers(testId, cs, filter, correctOutput) {
    print("> testFilterAttribNumbers#" + testId);

    var str = Changeset.filterAttribNumbers(cs, filter);
    assertEqualStrings(correctOutput, str);
  }

  testFilterAttribNumbers(1, "*0*1+1+2+3*1+4*2+5*0*2*1*b*c+6", function (n) {
    return (n % 2) == 0;
  }, "*0+1+2+3+4*2+5*0*2*c+6");
  testFilterAttribNumbers(2, "*0*1+1+2+3*1+4*2+5*0*2*1*b*c+6", function (n) {
    return (n % 2) == 1;
  }, "*1+1+2+3*1+4+5*1*b+6");

  function testInverse(testId, cs, lines, alines, pool, correctOutput) {
    print("> testInverse#" + testId);

    pool = poolOrArray(pool);
    var str = Changeset.inverse(Changeset.checkRep(cs), lines, alines, pool);
    assertEqualStrings(correctOutput, str);
  }

  // take "FFFFTTTTT" and apply "-FT--FFTT", the inverse of which is "--F--TT--"
  testInverse(1, "Z:9>0=1*0=1*1=1=2*0=2*1|1=2$", null, ["+4*1+5"], ['bold,', 'bold,true'], "Z:9>0=2*0=1=2*1=2$");

  function testMutateTextLines(testId, cs, lines, correctLines) {
    print("> testMutateTextLines#" + testId);

    var a = lines.slice();
    Changeset.mutateTextLines(cs, a);
    assertEqualArrays(correctLines, a);
  }

  testMutateTextLines(1, "Z:4<1|1-2-1|1+1+1$\nc", ["a\n", "b\n"], ["\n", "c\n"]);
  testMutateTextLines(2, "Z:4>0|1-2-1|2+3$\nc\n", ["a\n", "b\n"], ["\n", "c\n", "\n"]);

  function testInverseRandom(randomSeed) {
    var rand = new random();
    print("> testInverseRandom#" + randomSeed);

    var p = poolOrArray(['apple,', 'apple,true', 'banana,', 'banana,true']);

    var startText = randomMultiline(10, 20, rand) + '\n';
    var alines = Changeset.splitAttributionLines(Changeset.makeAttribution(startText), startText);
    var lines = startText.slice(0, -1).split('\n').map(function (s) {
      return s + '\n';
    });

    var stylifier = randomTestChangeset(startText, rand, true)[0];

    //print(alines.join('\n'));
    Changeset.mutateAttributionLines(stylifier, alines, p);
    //print(stylifier);
    //print(alines.join('\n'));
    Changeset.mutateTextLines(stylifier, lines);

    var changeset = randomTestChangeset(lines.join(''), rand, true)[0];
    var inverseChangeset = Changeset.inverse(changeset, lines, alines, p);

    var origLines = lines.slice();
    var origALines = alines.slice();

    Changeset.mutateTextLines(changeset, lines);
    Changeset.mutateAttributionLines(changeset, alines, p);
    //print(origALines.join('\n'));
    //print(changeset);
    //print(inverseChangeset);
    //print(origLines.map(function(s) { return '1: '+s.slice(0,-1); }).join('\n'));
    //print(lines.map(function(s) { return '2: '+s.slice(0,-1); }).join('\n'));
    //print(alines.join('\n'));
    Changeset.mutateTextLines(inverseChangeset, lines);
    Changeset.mutateAttributionLines(inverseChangeset, alines, p);
    //print(lines.map(function(s) { return '3: '+s.slice(0,-1); }).join('\n'));
    assertEqualArrays(origLines, lines);
    assertEqualArrays(origALines, alines);
  }

  for (var i = 0; i < 30; i++) testInverseRandom(i);
}

runTests();