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import {expect} from '@esm-bundle/chai';import {fakeHash, Hash} from '../hash';import {computeRefCountUpdates, GarbageCollectionDelegate} from './gc';
function createGraph(args: {  graph: Record<string, string[]>;  heads: string[];  allZeroRefCounts?: boolean;}) {  const {graph, heads, allZeroRefCounts} = args;  const hashes = Object.fromEntries(    Object.keys(graph).map(k => [k.toString(), fakeHash(k)]),  );  const refs = Object.fromEntries(    Object.entries(graph).map(([k, refs]) => [      hashes[k].toString(),      refs.map(v => hashes[v]),    ]),  );
  const refCounts = Object.fromEntries(    Object.keys(graph).map(k => [hashes[k].toString(), 0]),  );
  if (!allZeroRefCounts) {    const q = Array.from(new Set(heads));    for (const k of q) {      refCounts[hashes[k].toString()] = refCounts[hashes[k].toString()] + 1;      q.push(...graph[k]);    }  }
  const delegate: GarbageCollectionDelegate = {    getRefCount: async hash => refCounts[hash.toString()] || 0,    getRefs: async hash => refs[hash.toString()] || [],  };
  return {    hashes,    refCounts,    refs,    delegate,  };}
function expectRefCountUpdates(  actual: Map<Hash, number>,  expected: Record<string, number>,) {  const expectedAsMap = new Map(    Object.entries(expected).map(([k, v]) => [fakeHash(k), v]),  );  expect(actual).to.deep.equal(expectedAsMap);}
test('computeRefCountUpdates includes entry for every putChunk', async () => {  //   R    C  //  / \   |  // A   B  D  const {hashes, delegate} = createGraph({    graph: {      r: ['a', 'b'],      a: [],      b: [],      c: ['d'],      d: [],    },    heads: [],    allZeroRefCounts: true,  });
  const refCountUpdates = await computeRefCountUpdates(    [{old: undefined, new: hashes['r']}],    new Set(Object.values(hashes)),    delegate,  );  expectRefCountUpdates(refCountUpdates, {    r: 1,    a: 1,    b: 1,    c: 0,    d: 0,  });});
test('computeRefCountUpdates for basic diamond pattern', async () => {  // If we have a diamond structure we update the refcount for C twice.  //  //   R  //  / \  //  A  B  //  \ /  //   C
  const {hashes, delegate} = createGraph({    graph: {      r: ['a', 'b'],      a: ['c'],      b: ['c'],      c: [],    },    heads: ['r'],  });
  const eHash = fakeHash('e');  const refCountUpdates = await computeRefCountUpdates(    [{old: hashes['r'], new: eHash}],    new Set([eHash]),    delegate,  );  expectRefCountUpdates(refCountUpdates, {    r: 0,    a: 0,    b: 0,    c: 0,    e: 1,  });});
test('computeRefCountUpdates for a diamond pattern and a child', async () => {  // If we have a diamond structure we update the refcount for C twice.  //  //   R  //  / \  //  A  B  //  \ /  //   C  //   |  //   D
  const {hashes, delegate} = createGraph({    graph: {      r: ['a', 'b'],      a: ['c'],      b: ['c'],      c: ['d'],      d: [],    },    heads: ['r'],  });
  // Move test head from R to A  //  A  //  |  //  C  //  |  //  D  const refCountUpdates = await computeRefCountUpdates(    [{old: hashes['r'], new: hashes['a']}],    new Set(),    delegate,  );  expectRefCountUpdates(refCountUpdates, {    r: 0,    a: 1,    b: 0,    c: 1,  });});
test('computeRefCountUpdates for 3 incoming refs', async () => {  // If we have a diamond structure we update the refcount for D three times.  //  //    R  //  / | \  //  A B C  //  \ | /  //    D
  const {hashes, delegate} = createGraph({    graph: {      r: ['a', 'b', 'c'],      a: ['d'],      b: ['d'],      c: ['d'],      d: [],    },    heads: ['r'],  });
  const eHash = fakeHash('e');  const refCountUpdates = await computeRefCountUpdates(    [{old: hashes['r'], new: eHash}],    new Set([eHash]),    delegate,  );  expectRefCountUpdates(refCountUpdates, {    r: 0,    a: 0,    b: 0,    c: 0,    d: 0,    e: 1,  });});
test('computeRefCountUpdates for 3 incoming refs bypassing one level', async () => {  //    R  //  / | \  //  A B  |  //  \ | /  //    C
  const {hashes, delegate} = createGraph({    graph: {      r: ['a', 'b', 'c'],      a: ['c'],      b: ['c'],      c: [],    },    heads: ['r'],  });
  const eHash = fakeHash('e');  const refCountUpdates = await computeRefCountUpdates(    [{old: hashes['r'], new: eHash}],    new Set([eHash]),    delegate,  );  expectRefCountUpdates(refCountUpdates, {    r: 0,    a: 0,    b: 0,    c: 0,    e: 1,  });});