fix: perch scan stopped on a function inside a constructor that uses this

[jbrown9513]

perch scan stopped with function is not iterable (cannot read property Symbol(Symbol.iterator)) on a file like this:

export class Tenant extends Store {
  constructor() {
    super();
    const columns = table => this.sql.exec(table);
    columns('usage');
  }
}

To find where this.sql is assigned, the graph looks up the bases of the class around the caller. For columns, it takes the name of the method around it, constructor, as that class. A file's record keeps each class's bases in a plain object, so bases['constructor'] returned Object's own constructor, a function, and iterating it threw. A method named toString, valueOf or any other name on Object did the same. It needs a class with a base in the file, so the record has bases at all. 0.4.2 has the bug.

All six lookups of a class's bases in src/graph.js now go through basesOf, which reads only the record's own keys. Building the object without a prototype would not be enough: records parsed in a child process come back through JSON.

A new test in test/bindings.test.js covers the constructor and the toString cases. It fails with the TypeError without the change. npm run check passes: lint, typecheck and 671 tests.

Users don't need to change anything.

Closes #358

🤖 Generated with Claude Code

[perchcode-bot]

Perch Scan: no issues in 88 methods at 1677472.

See the scan