feat(zod-mock): pass path context to stringMap callbacks

[matt-halliday]

Problem

stringMap callbacks have no way to distinguish where in the schema a field was located. If the same field name (e.g. name) appeared under different parent objects, every instance received the same generated value, making it impossible to, say, produce an institution name vs. a person's name from a single name entry.

Limitation also highlighted in these issues, though this is arguably a more discrete solution than deep object stringMap support, or docblock/annotation parsing, and provides support for arrays and tuples if needed:
#141
#134

Proposed Solution

stringMap callbacks now receive a ctx argument with a path: (string | number)[] property, following the same convention used by Zod's own error objects, representing the full path to the current field.

const model = z.object({
  student:     z.object({ name: z.string() }),
  institution: z.object({ name: z.string() }),
});

generateMock(model, {
  stringMap: {
    name: ({ path }) =>
      path.includes('institution')
        ? faker.company.name()
        : faker.person.fullName(),
  },
});

Changes

• zod-mock.ts: parseObject now accumulates _path on options as it recurses, parseString passes { path } when invoking a stringMap generator.
• GenerateMockOptions: stringMap type updated from (...args: any[]) => string to ctx: StringMapContext) => string. _path added as an @internal field.
• StringMapContext: new exported interface

Backwards compatibility

Existing callbacks continue to work, the extra argument is silently ignored. All existing tests pass. One new test added.

The context is also an object so additions in future might be added without impacting any new consumers of this path implementation.

[nx-cloud]

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Command	Status	Duration	Result
nx affected:test --base=origin/main --codeCoverage	✅ Succeeded	5s	View ↗
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☁️ Nx Cloud last updated this comment at 2026-07-10 11:52:41 UTC