Function validateByRetainingPathFromNodes

test/common/heap.js:241–297

* A alternative heap snapshot validator that can be used to verify cppgc-managed nodes. * Modified from * https://chromium.googlesource.com/v8/v8/+/b00e995fb212737802810384ba2b868d0d92f7e5/test/unittests/heap/cppgc-js/unified-heap-snapshot-unittest.cc#134 * @param {object[]} nodes Snapshot nodes

(nodes, rootName, retainingPath, allowEmpty = false)

 *   assertion error.
 */
function validateByRetainingPathFromNodes(nodes, rootName, retainingPath, allowEmpty = false) {
  let haystack = nodes.filter((n) => n.name === rootName && n.type !== 'string');

  for (let i = 0; i < retainingPath.length; ++i) {
    const expected = retainingPath[i];
    const newHaystack = [];

    for (const parent of haystack) {
      for (let j = 0; j < parent.outgoingEdges.length; j++) {
        const edge = parent.outgoingEdges[j];
        // The strings are represented as { type: 'string', name: '<string content>' } in the snapshot.
        // Ignore them or we'll poke into strings that are just referenced as names of real nodes,
        // unless the caller is specifically looking for string nodes via `node_type`.
        let match = (edge.to.type !== 'string');
        if (expected.node_type) {
          match = (edge.to.type === expected.node_type);
        }
        if (expected.node_name && edge.to.name !== expected.node_name) {
          match = false;
        }
        if (expected.edge_name && edge.name !== expected.edge_name) {
          match = false;
        }
        if (expected.edge_type && edge.type !== expected.type) {
          match = false;
        }
        if (match) {
          newHaystack.push(edge.to);
        }
      }
    }

    if (newHaystack.length === 0) {
      if (allowEmpty) {
        return [];
      }
      const format = (val) => util.inspect(val, { breakLength: 128, depth: 3 });
      console.error('#');
      console.error('# Retaining path to search for:');
      for (let j = 0; j < retainingPath.length; ++j) {
        console.error(`# - '${format(retainingPath[j])}'${i === j ? '\t<--- not found' : ''}`);
      }
      console.error('#\n');
      console.error('# Nodes found in the last step include:');
      for (let j = 0; j < haystack.length; ++j) {
        console.error(`# - '${format(haystack[j])}`);
      }

      assert.fail(`Could not find target edge ${format(expected)} in the heap snapshot.`);

    }

    haystack = newHaystack;
  }

  return haystack;
}