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import {assert} from '@esm-bundle/chai';import * as dag from '../dag/mod';import * as db from '../db/mod';import * as utf8 from '../utf8';import {  BYTE_LENGTH,  Hash,  makeNewFakeHashFunction,  parse as parseHash,} from '../hash';import {BTreeWrite} from '../btree/write';import {ComputeHashTransformer} from './compute-hash-transformer';import {encode} from '../base32-encode';import type {ReadonlyJSONValue} from '../json';
test('fix hashes up of a single snapshot commit with empty btree', async () => {  const memdag = new dag.TestStore(    undefined,    makeNewFakeHashFunction('t/aaa'),    () => undefined,  );
  const [headChunk, treeChunk] = await memdag.withWrite(async dagWrite => {    const tree = new BTreeWrite(dagWrite);    const valueHash = await tree.flush();    const c = db.newSnapshot(      dagWrite.createChunk,      null,      0,      null,      valueHash,      [],    );    await dagWrite.putChunk(c.chunk);    await dagWrite.setHead('test', c.chunk.hash);    await dagWrite.commit();    return [c.chunk, await dagWrite.getChunk(valueHash)];  });
  const snapshot = memdag.kvStore.snapshot();  assert.deepEqual(snapshot, {    'c/t/aaa000000000000000000000000000/d': [0, []],    'c/t/aaa000000000000000000000000001/d': {      meta: {type: 3, basisHash: null, lastMutationID: 0, cookieJSON: null},      valueHash: 't/aaa000000000000000000000000000',      indexes: [],    },    'c/t/aaa000000000000000000000000001/m': [      't/aaa000000000000000000000000000',    ],    'h/test': 't/aaa000000000000000000000000001',    'c/t/aaa000000000000000000000000000/r': 1,    'c/t/aaa000000000000000000000000001/r': 1,  });
  if (!treeChunk) {    assert.fail();  }
  const gatheredChunk = new Map([    [headChunk.hash, headChunk],    [treeChunk.hash, treeChunk],  ]);
  const hashFunc = async (v: ReadonlyJSONValue): Promise<Hash> => {    const buf = await crypto.subtle.digest(      'SHA-512',      utf8.encode(JSON.stringify(v)),    );    const buf2 = new Uint8Array(buf, 0, BYTE_LENGTH);    return encode(buf2) as unknown as Hash;  };
  const transformer = new ComputeHashTransformer(gatheredChunk, hashFunc);  const newHeadHash = await transformer.transformCommit(headChunk.hash);  assert.equal(newHeadHash, parseHash('9lrb08p9b7jqo8oad3aef60muj4td8ke'));
  assert.deepEqual(Object.fromEntries(transformer.fixedChunks), {    'mdcncodijhl6jk2o8bb7m0hg15p3sf24': {      data: [0, []],      hash: 'mdcncodijhl6jk2o8bb7m0hg15p3sf24',      meta: [],    },    '9lrb08p9b7jqo8oad3aef60muj4td8ke': {      data: {        indexes: [],        meta: {          basisHash: null,          cookieJSON: null,          lastMutationID: 0,          type: 3,        },        valueHash: 'mdcncodijhl6jk2o8bb7m0hg15p3sf24',      },      hash: '9lrb08p9b7jqo8oad3aef60muj4td8ke',      meta: ['mdcncodijhl6jk2o8bb7m0hg15p3sf24'],    },  });
  {    // And again but only with the snapshot commit    memdag.kvStore.restoreSnapshot(snapshot);
    const gatheredChunk = new Map([[headChunk.hash, headChunk]]);
    const transformer = new ComputeHashTransformer(gatheredChunk, hashFunc);    const newHeadHash = await transformer.transformCommit(headChunk.hash);    assert.equal(newHeadHash, parseHash('1fgr18o8m8p503lt3e9oaoct8k9ch47b'));
    assert.deepEqual(Object.fromEntries(transformer.fixedChunks), {      '1fgr18o8m8p503lt3e9oaoct8k9ch47b': {        data: {          indexes: [],          meta: {            basisHash: null,            cookieJSON: null,            lastMutationID: 0,            type: 3,          },          valueHash: 't/aaa000000000000000000000000000',        },        hash: '1fgr18o8m8p503lt3e9oaoct8k9ch47b',        meta: ['t/aaa000000000000000000000000000'],      },    });  }});