fix(sample): make sample 34 test resilient to external package changes

[mag123c]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Sample 34 E2E test fails with superjson 2.2.3 due to exact JSON string matching

expected '{"jsonString":"{"json":{"big":"10"},"meta":{"values":{"big":["bigint"]}}}"}'
got      '{"jsonString":"{"json":{"big":"10"},"meta":{"values":{"big":["bigint"]},"v":1}}"}'

Sample 34's purpose is to demonstrate ESM package import, not to validate superjson's serialization format.

superjson 2.2.3 was published to npm on Oct 22, 2025 (06:20 UTC), and CI tests started failing immediately after. The package added a "v": 1 field to the meta object for backward compatibility

Root Cause

• Test uses exact JSON string comparison
• superjson 2.2.3 added internal version field for backward compatibility (PR #311)
• Test breaks on external package's internal format changes

Issue Number: #15834

What is the new behavior?

Changed test from exact JSON string matching to object comparison

// Before
.expect(
  JSON.stringify({
    jsonString: '{"json":{"big":"10"},"meta":{"values":{"big":["bigint"]}}}',
  }),
);

// After
.expect((res) => {
  const result = JSON.parse(res.body.jsonString);
  expect(result.json.big).toBe('10');
  expect(result.meta.values.big).toEqual(['bigint']);
});

Does this PR introduce a breaking change?

• Yes
• No

Other information

Related

• superjson issue: Input mapping is buggy flightcontrolhq/superjson#310
• superjson PR: fix: input escape mapping flightcontrolhq/superjson#311

Alternatives considered

1. Object comparison (implemented) - most robust
2. Pin superjson to 2.2.2 - prevents testing with latest packages
3. Update expected output to include "v": 1 - still fragile to future changes

[coveralls]

Pull Request Test Coverage Report for Build c7b4757d-3677-4e99-bb30-19d42de316cb

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 88.888%

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Totals
Change from base Build 3a48f653-e287-441b-b2b2-c3e90f54cf30:	0.0%
Covered Lines:	7319
Relevant Lines:	8234

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💛 - Coveralls