diff --git a/src/static/js/Changeset.ts b/src/static/js/Changeset.ts
index 079f82769..8d96e157b 100644
--- a/src/static/js/Changeset.ts
+++ b/src/static/js/Changeset.ts
@@ -1276,7 +1276,7 @@ export const subattribution = (astr: string, start: number, optEnd?: number) =>
   return assem.toString();
 };
 
-export const inverse = (cs: string, lines: string|RegExpMatchArray | null, alines: string[]|{
+export const inverse = (cs: string, lines: string|RegExpMatchArray|string[] | null, alines: string[]|{
   get: (idx: number) => string,
 }, pool: AttributePool) => {
   // lines and alines are what the exports is meant to apply to.
diff --git a/src/tests/backend/specs/admin_utils.ts b/src/tests/backend-new/specs/admin_utils.ts
similarity index 55%
rename from src/tests/backend/specs/admin_utils.ts
rename to src/tests/backend-new/specs/admin_utils.ts
index bd8690445..b115a38a6 100644
--- a/src/tests/backend/specs/admin_utils.ts
+++ b/src/tests/backend-new/specs/admin_utils.ts
@@ -2,37 +2,37 @@
 
 
 import {strict as assert} from "assert";
-import {cleanComments, minify} from "../../../../admin/src/utils/utils.js";
-
-const fs = require('fs');
+import {cleanComments, minify} from "admin/src/utils/utils";
+import {describe, it, expect, beforeAll} from "vitest";
+import fs from 'fs';
 const fsp = fs.promises;
 let template:string;
 
 describe(__filename, function () {
-  before(async function () {
+  beforeAll(async function () {
     template = await fsp.readFile('../settings.json.template', 'utf8')
   });
   describe('adminUtils', function () {
     it('cleanComments function empty', async function () {
-      assert.equal(cleanComments(""), "");
+      expect(cleanComments("")).to.equal("");
     });
     it('cleanComments function HelloWorld no comment', async function () {
-      assert.equal(cleanComments("HelloWorld"), "HelloWorld");
+      expect(cleanComments("HelloWorld")).to.equal("HelloWorld");
     });
     it('cleanComments function HelloWorld with comment', async function () {
-      assert.equal(cleanComments("Hello/*abc*/World/*def*/"), "HelloWorld");
+      expect(cleanComments("Hello/*abc*/World/*def*/")).to.equal("HelloWorld");
     });
     it('cleanComments function HelloWorld with comment and multiline', async function () {
-      assert.equal(cleanComments("Hello \n/*abc\nxyz*/World/*def*/"), "Hello\nWorld");
+      expect(cleanComments("Hello \n/*abc\nxyz*/World/*def*/")).to.equal("Hello\nWorld");
     });
     it('cleanComments function HelloWorld with multiple line breaks', async function () {
-      assert.equal(cleanComments("  \nHello \n  \n  \nWorld/*def*/"), "Hello\nWorld");
+      expect(cleanComments("  \nHello \n  \n  \nWorld/*def*/")).to.equal("Hello\nWorld");
     });
     it('cleanComments function same after minified', async function () {
-      assert.equal(minify(template), minify(cleanComments(template)!));
+      expect(minify(cleanComments(template)!)).to.equal(minify(template));
     });
     it('minified results are smaller', async function () {
-      assert.equal(minify(template).length < template.length, true);
+      expect(minify(template).length < template.length).to.equal(true);
     });
   });
 });
diff --git a/src/tests/frontend/specs/easysync-inverseRandom.js b/src/tests/backend-new/specs/easysync-inverseRandom.ts
similarity index 51%
rename from src/tests/frontend/specs/easysync-inverseRandom.js
rename to src/tests/backend-new/specs/easysync-inverseRandom.ts
index 41ef86d57..a9b743c76 100644
--- a/src/tests/frontend/specs/easysync-inverseRandom.js
+++ b/src/tests/backend-new/specs/easysync-inverseRandom.ts
@@ -1,34 +1,36 @@
 'use strict';
 
-const Changeset = require('../../../static/js/Changeset');
-const {randomMultiline, randomTestChangeset, poolOrArray} = require('../easysync-helper.js');
+import AttributePool from '../../../static/js/AttributePool';
+import {checkRep, inverse, makeAttribution, mutateAttributionLines, mutateTextLines, splitAttributionLines} from '../../../static/js/Changeset';
+import {randomMultiline, randomTestChangeset, poolOrArray} from '../easysync-helper.js';
+import {expect, describe, it} from 'vitest'
 
 describe('easysync-inverseRandom', function () {
   describe('inverse random', function () {
-    const testInverseRandom = (randomSeed) => {
+    const testInverseRandom = (randomSeed: number) => {
       it(`testInverseRandom#${randomSeed}`, async function () {
         const p = poolOrArray(['apple,', 'apple,true', 'banana,', 'banana,true']);
 
         const startText = `${randomMultiline(10, 20)}\n`;
         const alines =
-            Changeset.splitAttributionLines(Changeset.makeAttribution(startText), startText);
+          splitAttributionLines(makeAttribution(startText), startText);
         const lines = startText.slice(0, -1).split('\n').map((s) => `${s}\n`);
 
         const stylifier = randomTestChangeset(startText, true)[0];
 
-        Changeset.mutateAttributionLines(stylifier, alines, p);
-        Changeset.mutateTextLines(stylifier, lines);
+        mutateAttributionLines(stylifier, alines, p);
+        mutateTextLines(stylifier, lines);
 
         const changeset = randomTestChangeset(lines.join(''), true)[0];
-        const inverseChangeset = Changeset.inverse(changeset, lines, alines, p);
+        const inverseChangeset = inverse(changeset, lines, alines, p);
 
         const origLines = lines.slice();
         const origALines = alines.slice();
 
-        Changeset.mutateTextLines(changeset, lines);
-        Changeset.mutateAttributionLines(changeset, alines, p);
-        Changeset.mutateTextLines(inverseChangeset, lines);
-        Changeset.mutateAttributionLines(inverseChangeset, alines, p);
+        mutateTextLines(changeset, lines);
+        mutateAttributionLines(changeset, alines, p);
+        mutateTextLines(inverseChangeset, lines);
+        mutateAttributionLines(inverseChangeset, alines, p);
         expect(lines).to.eql(origLines);
         expect(alines).to.eql(origALines);
       });
@@ -38,10 +40,10 @@ describe('easysync-inverseRandom', function () {
   });
 
   describe('inverse', function () {
-    const testInverse = (testId, cs, lines, alines, pool, correctOutput) => {
+    const testInverse = (testId: number, cs: string, lines: string | RegExpMatchArray | null, alines: string[] | { get: (idx: number) => string; }, pool: string[] | AttributePool, correctOutput: string) => {
       it(`testInverse#${testId}`, async function () {
         pool = poolOrArray(pool);
-        const str = Changeset.inverse(Changeset.checkRep(cs), lines, alines, pool);
+        const str = inverse(checkRep(cs), lines, alines, pool as AttributePool);
         expect(str).to.equal(correctOutput);
       });
     };
diff --git a/src/tests/frontend/specs/easysync-assembler.spec.mjs b/src/tests/frontend/specs/easysync-assembler.spec.mjs
deleted file mode 100644
index ffccfc7e3..000000000
--- a/src/tests/frontend/specs/easysync-assembler.spec.mjs
+++ /dev/null
@@ -1,219 +0,0 @@
-'use strict';
-
-const Changeset = require('../../../static/js/Changeset');
-const {padutils} = require('../../../static/js/pad_utils');
-const {poolOrArray} = require('../easysync-helper.js');
-
-import {describe, it, expect} from 'vitest'
-
-
-describe('easysync-assembler', function () {
-  it('opAssembler', async function () {
-    const x = '-c*3*4+6|3=az*asdf0*1*2*3+1=1-1+1*0+1=1-1+1|c=c-1';
-    const assem = Changeset.opAssembler();
-    var opLength = 0
-    for (const op of Changeset.deserializeOps(x)){
-      console.log(op)
-      assem.append(op);
-      opLength++
-    }
-    expect(assem.toString()).to.equal(x);
-  });
-
-  it('smartOpAssembler', async function () {
-    const x = '-c*3*4+6|3=az*asdf0*1*2*3+1=1-1+1*0+1=1-1+1|c=c-1';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal(x);
-  });
-
-  it('smartOpAssembler ignore additional pure keeps (no attributes)', async function () {
-    const x = '-c*3*4+6|1+1=5';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-c*3*4+6|1+1');
-  });
-
-  it('smartOpAssembler merge consecutive + ops without multiline', async function () {
-    const x = '-c*3*4+6*3*4+1*3*4+9=5';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-c*3*4+g');
-  });
-
-  it('smartOpAssembler merge consecutive + ops with multiline', async function () {
-    const x = '-c*3*4+6*3*4|1+1*3*4|9+f*3*4+k=5';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-c*3*4|a+m*3*4+k');
-  });
-
-  it('smartOpAssembler merge consecutive - ops without multiline', async function () {
-    const x = '-c-6-1-9=5';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-s');
-  });
-
-  it('smartOpAssembler merge consecutive - ops with multiline', async function () {
-    const x = '-c-6|1-1|9-f-k=5';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('|a-y-k');
-  });
-
-  it('smartOpAssembler merge consecutive = ops without multiline', async function () {
-    const x = '-c*3*4=6*2*4=1*3*4=f*3*4=2*3*4=a=k=5';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-c*3*4=6*2*4=1*3*4=r');
-  });
-
-  it('smartOpAssembler merge consecutive = ops with multiline', async function () {
-    const x = '-c*3*4=6*2*4|1=1*3*4|9=f*3*4|2=2*3*4=a*3*4=1=k=5';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-c*3*4=6*2*4|1=1*3*4|b=h*3*4=b');
-  });
-
-  it('smartOpAssembler ignore + ops with ops.chars === 0', async function () {
-    const x = '-c*3*4+6*3*4+0*3*4+1+0*3*4+1';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-c*3*4+8');
-  });
-
-  it('smartOpAssembler ignore - ops with ops.chars === 0', async function () {
-    const x = '-c-6-0-1-0-1';
-    const assem = Changeset.smartOpAssembler();
-    for (const op of Changeset.deserializeOps(x)) assem.append(op);
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-k');
-  });
-
-  it('smartOpAssembler append + op with text', async function () {
-    const assem = Changeset.smartOpAssembler();
-    const pool = poolOrArray([
-      'attr1,1',
-      'attr2,2',
-      'attr3,3',
-      'attr4,4',
-      'attr5,5',
-    ]);
-
-    padutils.warnDeprecated.disabledForTestingOnly = true;
-    try {
-      assem.appendOpWithText('+', 'test', '*3*4*5', pool);
-      assem.appendOpWithText('+', 'test', '*3*4*5', pool);
-      assem.appendOpWithText('+', 'test', '*1*4*5', pool);
-    } finally {
-      delete padutils.warnDeprecated.disabledForTestingOnly;
-    }
-    assem.endDocument();
-    expect(assem.toString()).to.equal('*3*4*5+8*1*4*5+4');
-  });
-
-  it('smartOpAssembler append + op with multiline text', async function () {
-    const assem = Changeset.smartOpAssembler();
-    const pool = poolOrArray([
-      'attr1,1',
-      'attr2,2',
-      'attr3,3',
-      'attr4,4',
-      'attr5,5',
-    ]);
-
-    padutils.warnDeprecated.disabledForTestingOnly = true;
-    try {
-      assem.appendOpWithText('+', 'test\ntest', '*3*4*5', pool);
-      assem.appendOpWithText('+', '\ntest\n', '*3*4*5', pool);
-      assem.appendOpWithText('+', '\ntest', '*1*4*5', pool);
-    } finally {
-      delete padutils.warnDeprecated.disabledForTestingOnly;
-    }
-    assem.endDocument();
-    expect(assem.toString()).to.equal('*3*4*5|3+f*1*4*5|1+1*1*4*5+4');
-  });
-
-  it('smartOpAssembler clear should empty internal assemblers', async function () {
-    const x = '-c*3*4+6|3=az*asdf0*1*2*3+1=1-1+1*0+1=1-1+1|c=c-1';
-    const ops = Changeset.deserializeOps(x);
-    const iter = {
-      _n: ops.next(),
-      hasNext() { return !this._n.done; },
-      next() { const v = this._n.value; this._n = ops.next(); return v; },
-    };
-    const assem = Changeset.smartOpAssembler();
-    var iter1 = iter.next()
-    assem.append(iter1);
-    var iter2 = iter.next()
-    assem.append(iter2);
-    var iter3 = iter.next()
-    assem.append(iter3);
-    console.log(assem.toString());
-    assem.clear();
-    assem.append(iter.next());
-    assem.append(iter.next());
-    console.log(assem.toString());
-    assem.clear();
-    let counter = 0;
-    while (iter.hasNext()) {
-      console.log(counter++)
-      assem.append(iter.next());
-    }
-    assem.endDocument();
-    expect(assem.toString()).to.equal('-1+1*0+1=1-1+1|c=c-1');
-  });
-
-  describe('append atext to assembler', function () {
-    const testAppendATextToAssembler = (testId, atext, correctOps) => {
-      it(`testAppendATextToAssembler#${testId}`, async function () {
-        const assem = Changeset.smartOpAssembler();
-        for (const op of Changeset.opsFromAText(atext)) assem.append(op);
-        expect(assem.toString()).to.equal(correctOps);
-      });
-    };
-
-    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');
-  });
-});
diff --git a/src/tests/frontend/specs/easysync-compose.js b/src/tests/frontend/specs/easysync-compose.js
deleted file mode 100644
index 69757763c..000000000
--- a/src/tests/frontend/specs/easysync-compose.js
+++ /dev/null
@@ -1,53 +0,0 @@
-'use strict';
-
-const Changeset = require('../../../static/js/Changeset');
-const AttributePool = require('../../../static/js/AttributePool');
-const {randomMultiline, randomTestChangeset} = require('../easysync-helper.js');
-
-describe('easysync-compose', function () {
-  describe('compose', function () {
-    const testCompose = (randomSeed) => {
-      it(`testCompose#${randomSeed}`, async function () {
-        const p = new AttributePool();
-
-        const startText = `${randomMultiline(10, 20)}\n`;
-
-        const x1 = randomTestChangeset(startText);
-        const change1 = x1[0];
-        const text1 = x1[1];
-
-        const x2 = randomTestChangeset(text1);
-        const change2 = x2[0];
-        const text2 = x2[1];
-
-        const x3 = randomTestChangeset(text2);
-        const change3 = x3[0];
-        const text3 = x3[1];
-
-        const change12 = Changeset.checkRep(Changeset.compose(change1, change2, p));
-        const change23 = Changeset.checkRep(Changeset.compose(change2, change3, p));
-        const change123 = Changeset.checkRep(Changeset.compose(change12, change3, p));
-        const change123a = Changeset.checkRep(Changeset.compose(change1, change23, p));
-        expect(change123a).to.equal(change123);
-
-        expect(Changeset.applyToText(change12, startText)).to.equal(text2);
-        expect(Changeset.applyToText(change23, text1)).to.equal(text3);
-        expect(Changeset.applyToText(change123, startText)).to.equal(text3);
-      });
-    };
-
-    for (let i = 0; i < 30; i++) testCompose(i);
-  });
-
-  describe('compose attributes', function () {
-    it('simpleComposeAttributesTest', async function () {
-      const p = new AttributePool();
-      p.putAttrib(['bold', '']);
-      p.putAttrib(['bold', 'true']);
-      const cs1 = Changeset.checkRep('Z:2>1*1+1*1=1$x');
-      const cs2 = Changeset.checkRep('Z:3>0*0|1=3$');
-      const cs12 = Changeset.checkRep(Changeset.compose(cs1, cs2, p));
-      expect(cs12).to.equal('Z:2>1+1*0|1=2$x');
-    });
-  });
-});
diff --git a/src/tests/frontend/specs/easysync-mutations.js b/src/tests/frontend/specs/easysync-mutations.js
deleted file mode 100644
index c10d34519..000000000
--- a/src/tests/frontend/specs/easysync-mutations.js
+++ /dev/null
@@ -1,313 +0,0 @@
-'use strict';
-
-const Changeset = require('../../../static/js/Changeset');
-const AttributePool = require('../../../static/js/AttributePool');
-const {poolOrArray} = require('../easysync-helper.js');
-
-describe('easysync-mutations', function () {
-  const applyMutations = (mu, arrayOfArrays) => {
-    arrayOfArrays.forEach((a) => {
-      const result = mu[a[0]](...a.slice(1));
-      if (a[0] === 'remove' && a[3]) {
-        expect(result).to.equal(a[3]);
-      }
-    });
-  };
-
-  const mutationsToChangeset = (oldLen, arrayOfArrays) => {
-    const assem = Changeset.smartOpAssembler();
-    const op = new Changeset.Op();
-    const bank = Changeset.stringAssembler();
-    let oldPos = 0;
-    let newLen = 0;
-    arrayOfArrays.forEach((a) => {
-      if (a[0] === 'skip') {
-        op.opcode = '=';
-        op.chars = a[1];
-        op.lines = (a[2] || 0);
-        assem.append(op);
-        oldPos += op.chars;
-        newLen += op.chars;
-      } else if (a[0] === 'remove') {
-        op.opcode = '-';
-        op.chars = a[1];
-        op.lines = (a[2] || 0);
-        assem.append(op);
-        oldPos += op.chars;
-      } else if (a[0] === 'insert') {
-        op.opcode = '+';
-        bank.append(a[1]);
-        op.chars = a[1].length;
-        op.lines = (a[2] || 0);
-        assem.append(op);
-        newLen += op.chars;
-      }
-    });
-    newLen += oldLen - oldPos;
-    assem.endDocument();
-    return Changeset.pack(oldLen, newLen, assem.toString(), bank.toString());
-  };
-
-  const runMutationTest = (testId, origLines, muts, correct) => {
-    it(`runMutationTest#${testId}`, async function () {
-      let lines = origLines.slice();
-      const mu = new Changeset.exportedForTestingOnly.TextLinesMutator(lines);
-      applyMutations(mu, muts);
-      mu.close();
-      expect(lines).to.eql(correct);
-
-      const inText = origLines.join('');
-      const cs = mutationsToChangeset(inText.length, muts);
-      lines = origLines.slice();
-      Changeset.mutateTextLines(cs, lines);
-      expect(lines).to.eql(correct);
-
-      const correctText = correct.join('');
-      const outText = Changeset.applyToText(cs, inText);
-      expect(outText).to.equal(correctText);
-    });
-  };
-
-  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']);
-
-  it('mutatorHasMore', async function () {
-    const lines = ['1\n', '2\n', '3\n', '4\n'];
-    let mu;
-
-    mu = new Changeset.exportedForTestingOnly.TextLinesMutator(lines);
-    expect(mu.hasMore()).to.be(true);
-    mu.skip(8, 4);
-    expect(mu.hasMore()).to.be(false);
-    mu.close();
-    expect(mu.hasMore()).to.be(false);
-
-    // still 1,2,3,4
-    mu = new Changeset.exportedForTestingOnly.TextLinesMutator(lines);
-    expect(mu.hasMore()).to.be(true);
-    mu.remove(2, 1);
-    expect(mu.hasMore()).to.be(true);
-    mu.skip(2, 1);
-    expect(mu.hasMore()).to.be(true);
-    mu.skip(2, 1);
-    expect(mu.hasMore()).to.be(true);
-    mu.skip(2, 1);
-    expect(mu.hasMore()).to.be(false);
-    mu.insert('5\n', 1);
-    expect(mu.hasMore()).to.be(false);
-    mu.close();
-    expect(mu.hasMore()).to.be(false);
-
-    // 2,3,4,5 now
-    mu = new Changeset.exportedForTestingOnly.TextLinesMutator(lines);
-    expect(mu.hasMore()).to.be(true);
-    mu.remove(6, 3);
-    expect(mu.hasMore()).to.be(true);
-    mu.remove(2, 1);
-    expect(mu.hasMore()).to.be(false);
-    mu.insert('hello\n', 1);
-    expect(mu.hasMore()).to.be(false);
-    mu.close();
-    expect(mu.hasMore()).to.be(false);
-  });
-
-  describe('mutateTextLines', function () {
-    const testMutateTextLines = (testId, cs, lines, correctLines) => {
-      it(`testMutateTextLines#${testId}`, async function () {
-        const a = lines.slice();
-        Changeset.mutateTextLines(cs, a);
-        expect(a).to.eql(correctLines);
-      });
-    };
-
-    testMutateTextLines(1, 'Z:4<1|1-2-1|1+1+1$\nc', ['a\n', 'b\n'], ['\n', 'c\n']);
-    testMutateTextLines(2, 'Z:4>0|1-2-1|2+3$\nc\n', ['a\n', 'b\n'], ['\n', 'c\n', '\n']);
-
-    it('mutate keep only lines', async function () {
-      const lines = ['1\n', '2\n', '3\n', '4\n'];
-      const result = lines.slice();
-      const cs = 'Z:8>0*0|1=2|2=2';
-
-      Changeset.mutateTextLines(cs, lines);
-      expect(result).to.eql(lines);
-    });
-  });
-
-  describe('mutate attributions', function () {
-    const testPoolWithChars = (() => {
-      const p = new AttributePool();
-      p.putAttrib(['char', 'newline']);
-      for (let i = 1; i < 36; i++) {
-        p.putAttrib(['char', Changeset.numToString(i)]);
-      }
-      p.putAttrib(['char', '']);
-      return p;
-    })();
-
-    const runMutateAttributionTest = (testId, attribs, cs, alines, outCorrect) => {
-      it(`runMutateAttributionTest#${testId}`, async function () {
-        const p = poolOrArray(attribs);
-        const alines2 = Array.prototype.slice.call(alines);
-        Changeset.mutateAttributionLines(Changeset.checkRep(cs), alines2, p);
-        expect(alines2).to.eql(outCorrect);
-
-        const removeQuestionMarks = (a) => a.replace(/\?/g, '');
-        const inMerged = Changeset.joinAttributionLines(alines.map(removeQuestionMarks));
-        const correctMerged = Changeset.joinAttributionLines(outCorrect.map(removeQuestionMarks));
-        const mergedResult = Changeset.applyToAttribution(cs, inMerged, p);
-        expect(mergedResult).to.equal(correctMerged);
-      });
-    };
-
-    // 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']);
-
-    // 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$\n',
-        ['*0|1+4', '*0|1+8', '*0+5|1+1', '*0|1+1', '*0|1+5', '*0|1+1', '*0|1+1', '*0|1+1', '|1+1'],
-        [
-          '*0|1+4',
-          '*0+6|1+1',
-          '*0|1+2',
-          '*0+5|1+1',
-          '*0|1+1',
-          '*0|1+5',
-          '*0|1+1',
-          '*0|1+1',
-          '*0|1+1',
-          '|1+1',
-        ]);
-  });
-});
diff --git a/src/tests/frontend/specs/easysync-other.test.mjs b/src/tests/frontend/specs/easysync-other.test.mjs
deleted file mode 100644
index 3c0bdff7c..000000000
--- a/src/tests/frontend/specs/easysync-other.test.mjs
+++ /dev/null
@@ -1,161 +0,0 @@
-'use strict';
-
-const Changeset = require('../../../static/js/Changeset');
-const AttributePool = require('../../../static/js/AttributePool');
-const {randomMultiline, poolOrArray} = require('../easysync-helper.js');
-const {padutils} = require('../../../static/js/pad_utils');
-import {describe, it, expect} from 'vitest'
-
-
-describe('easysync-other', function () {
-  describe('filter attribute numbers', function () {
-    const testFilterAttribNumbers = (testId, cs, filter, correctOutput) => {
-      it(`testFilterAttribNumbers#${testId}`, async function () {
-        const str = Changeset.filterAttribNumbers(cs, filter);
-        expect(str).to.equal(correctOutput);
-      });
-    };
-
-    testFilterAttribNumbers(1, '*0*1+1+2+3*1+4*2+5*0*2*1*b*c+6',
-        (n) => (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',
-        (n) => (n % 2) === 1, '*1+1+2+3*1+4+5*1*b+6');
-  });
-
-  describe('make attribs string', function () {
-    const testMakeAttribsString = (testId, pool, opcode, attribs, correctString) => {
-      it(`testMakeAttribsString#${testId}`, async function () {
-        const p = poolOrArray(pool);
-        padutils.warnDeprecated.disabledForTestingOnly = true;
-        try {
-          expect(Changeset.makeAttribsString(opcode, attribs, p)).to.equal(correctString);
-        } finally {
-          delete padutils.warnDeprecated.disabledForTestingOnly;
-        }
-      });
-    };
-
-    testMakeAttribsString(1, ['bold,'], '+', [
-      ['bold', ''],
-    ], '');
-    testMakeAttribsString(2, ['abc,def', 'bold,'], '=', [
-      ['bold', ''],
-    ], '*1');
-    testMakeAttribsString(3, ['abc,def', 'bold,true'], '+', [
-      ['abc', 'def'],
-      ['bold', 'true'],
-    ], '*0*1');
-    testMakeAttribsString(4, ['abc,def', 'bold,true'], '+', [
-      ['bold', 'true'],
-      ['abc', 'def'],
-    ], '*0*1');
-  });
-
-  describe('other', function () {
-    it('testMoveOpsToNewPool', async function () {
-      const pool1 = new AttributePool();
-      const pool2 = new AttributePool();
-
-      pool1.putAttrib(['baz', 'qux']);
-      pool1.putAttrib(['foo', 'bar']);
-
-      pool2.putAttrib(['foo', 'bar']);
-
-      expect(Changeset.moveOpsToNewPool('Z:1>2*1+1*0+1$ab', pool1, pool2))
-          .to.equal('Z:1>2*0+1*1+1$ab');
-      expect(Changeset.moveOpsToNewPool('*1+1*0+1', pool1, pool2)).to.equal('*0+1*1+1');
-    });
-
-    it('testMakeSplice', async function () {
-      const t = 'a\nb\nc\n';
-      let splice = Changeset.makeSplice(t, 5, 0, 'def')
-      const t2 = Changeset.applyToText(splice, t);
-      expect(t2).to.equal('a\nb\ncdef\n');
-    });
-
-    it('makeSplice at the end', async function () {
-      const orig = '123';
-      const ins = '456';
-      expect(Changeset.applyToText(Changeset.makeSplice(orig, orig.length, 0, ins), orig))
-          .to.equal(`${orig}${ins}`);
-    });
-
-    it('testToSplices', async function () {
-      const cs = Changeset.checkRep('Z:z>9*0=1=4-3+9=1|1-4-4+1*0+a$123456789abcdefghijk');
-      const correctSplices = [
-        [5, 8, '123456789'],
-        [9, 17, 'abcdefghijk'],
-      ];
-      expect(Changeset.exportedForTestingOnly.toSplices(cs)).to.eql(correctSplices);
-    });
-
-    it('opAttributeValue', async function () {
-      const p = new AttributePool();
-      p.putAttrib(['name', 'david']);
-      p.putAttrib(['color', 'green']);
-
-      const stringOp = (str) => Changeset.deserializeOps(str).next().value;
-
-      padutils.warnDeprecated.disabledForTestingOnly = true;
-      try {
-        expect(Changeset.opAttributeValue(stringOp('*0*1+1'), 'name', p)).to.equal('david');
-        expect(Changeset.opAttributeValue(stringOp('*0+1'), 'name', p)).to.equal('david');
-        expect(Changeset.opAttributeValue(stringOp('*1+1'), 'name', p)).to.equal('');
-        expect(Changeset.opAttributeValue(stringOp('+1'), 'name', p)).to.equal('');
-        expect(Changeset.opAttributeValue(stringOp('*0*1+1'), 'color', p)).to.equal('green');
-        expect(Changeset.opAttributeValue(stringOp('*1+1'), 'color', p)).to.equal('green');
-        expect(Changeset.opAttributeValue(stringOp('*0+1'), 'color', p)).to.equal('');
-        expect(Changeset.opAttributeValue(stringOp('+1'), 'color', p)).to.equal('');
-      } finally {
-        delete padutils.warnDeprecated.disabledForTestingOnly;
-      }
-    });
-
-    describe('applyToAttribution', function () {
-      const runApplyToAttributionTest = (testId, attribs, cs, inAttr, outCorrect) => {
-        it(`applyToAttribution#${testId}`, async function () {
-          const p = poolOrArray(attribs);
-          const result = Changeset.applyToAttribution(Changeset.checkRep(cs), inAttr, p);
-          expect(result).to.equal(outCorrect);
-        });
-      };
-
-      // 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');
-    });
-
-    describe('split/join attribution lines', function () {
-      const testSplitJoinAttributionLines = (randomSeed) => {
-        const stringToOps = (str) => {
-          const assem = Changeset.mergingOpAssembler();
-          const o = new Changeset.Op('+');
-          o.chars = 1;
-          for (let i = 0; i < str.length; i++) {
-            const c = str.charAt(i);
-            o.lines = (c === '\n' ? 1 : 0);
-            o.attribs = (c === 'a' || c === 'b' ? `*${c}` : '');
-            assem.append(o);
-          }
-          return assem.toString();
-        };
-
-        it(`testSplitJoinAttributionLines#${randomSeed}`, async function () {
-          const doc = `${randomMultiline(10, 20)}\n`;
-
-          const theJoined = stringToOps(doc);
-          const theSplit = doc.match(/[^\n]*\n/g).map(stringToOps);
-
-          expect(Changeset.splitAttributionLines(theJoined, doc)).to.eql(theSplit);
-          expect(Changeset.joinAttributionLines(theSplit)).to.equal(theJoined);
-        });
-      };
-
-      for (let i = 0; i < 10; i++) testSplitJoinAttributionLines(i);
-    });
-  });
-});
diff --git a/src/tests/frontend/specs/easysync-subAttribution.js b/src/tests/frontend/specs/easysync-subAttribution.js
deleted file mode 100644
index 0cb4e8f7c..000000000
--- a/src/tests/frontend/specs/easysync-subAttribution.js
+++ /dev/null
@@ -1,55 +0,0 @@
-'use strict';
-
-const Changeset = require('../../../static/js/Changeset');
-
-describe('easysync-subAttribution', function () {
-  const testSubattribution = (testId, astr, start, end, correctOutput) => {
-    it(`subattribution#${testId}`, async function () {
-      const str = Changeset.subattribution(astr, start, end);
-      expect(str).to.equal(correctOutput);
-    });
-  };
-
-  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');
-});