fix: use-default-on-jsonpath-import

[Zaimwa9]

• Jsonpath library only exports a default object in ESM mode, meaning import * as jsonpath couldn't access submethods like jsonpath.query
• All the jsonpath evaluation would throw a silent error and not evaluate
• This wasn't caught by the tests as they are running in a commonJS context => automatically handles it

---

Details of the difference between the two systems:

⏺ CommonJS (CJS) - Node.js original module system:
  // Exporting
  module.exports = { query: function() {} }

  // Importing
  const jsonpath = require('jsonpath')
  jsonpath.query()  // ✓ works

  ES Modules (ESM) - Modern JavaScript standard:
  // Exporting
  export default { query: function() {} }
  export const query = function() {}

  // Importing
  import jsonpath from 'jsonpath'      // gets default export
  import * as jsonpath from 'jsonpath' // gets namespace object

  The problem: When a CJS library (like jsonpath) is imported in ESM:
  - import * as jsonpath creates a namespace object where the CJS module.exports becomes jsonpath.default
  - So jsonpath.query is undefined, but jsonpath.default.query works

[khvn26]

Approving, but I strongly suggest adding a test run in ESM mode to CI, if possible.

[Zaimwa9]

@khvn26 https://github.com/Flagsmith/flagsmith-nodejs-client/actions/runs/19830086799/job/56813609828?pr=231

New step Run npm run test:esm-build that works on esm

      - run: npm run test:esm-build
        env:
          CI: true

Tests relying on mocks have been skipped due to incompatibilities with vi.mock. (Mostly the percentage_split, version one).

The previous tests are still running so this step is mostly to catch similar issues (that would have been caught)

FAIL  tests/engine/unit/engine.test.ts > test_get_evaluation_result_with_identity_override_and_no_segment_override
AssertionError: expected false to be true // Object.is equality

- Expected
+ Received

- true
+ false

 ❯ tests/engine/unit/engine.test.ts:57:30
     55|         const expected = flag.name === 'overridden_feature' ? true : environmentFeat…
     56| 
     57|         expect(flag.enabled).toBe(expected);
       |                              ^
     58|         expect(flag.reason).toBe(
     59|             flag.name === 'overridden_feature'

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 FAIL  tests/engine/unit/engine.test.ts > evaluateSegments handles segments with identity identifier matching
AssertionError: expected [] to have a length of 2 but got +0

- Expected
+ Received

- 2
+ 0

 ❯ tests/engine/unit/engine.test.ts:195:29
    193|     const result = evaluateSegments(context as any);
    194| 
    195|     expect(result.segments).toHaveLength(2);
       |                             ^
    196|     expect(result.segments).toEqual(
    197|         expect.arrayContaining([

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 FAIL  tests/engine/unit/engine.test.ts > evaluateSegments handles priority conflicts correctly
AssertionError: expected [] to have a length of 2 but got +0

- Expected
+ Received

- 2
+ 0

 ❯ tests/engine/unit/engine.test.ts:282:29
    280|     const result = evaluateSegments(context as any);
    281| 
    282|     expect(result.segments).toHaveLength(2);
       |                             ^
    283| 
    284|     expect(result.segmentOverrides.feature1.segmentName).toBe('high_priority_segment…

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 FAIL  tests/engine/unit/segments/segment_evaluators.test.ts > IN operator > evaluates IN condition {"property":"undefined","operator":"IN","value":["test","john-doe"]} to true
 FAIL  tests/engine/unit/segments/segment_evaluators.test.ts > IN operator > evaluates IN condition {"property":"undefined","operator":"IN","value":"[\"test\", \"john-doe\"]"} to true
 FAIL  tests/engine/unit/segments/segment_evaluators.test.ts > IN operator > evaluates IN condition {"property":"undefined","operator":"IN","value":"test,john-doe"} to true
AssertionError: expected false to be true // Object.is equality

- Expected
+ Received

- true
+ false

 ❯ tests/engine/unit/segments/segment_evaluators.test.ts:244:28
    242|         (condition: SegmentCondition | InSegmentCondition, expected: boolean) => {
    243|             const result = traitsMatchSegmentCondition(condition, 'segment', mockCon…
    244|             expect(result).toBe(expected);
       |                            ^
    245|         }
    246|     );

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 FAIL  tests/engine/unit/segments/segment_evaluators.test.ts > getIdentitySegments single segment evaluation > returns segment when all rules match
AssertionError: expected [] to have a length of 1 but got +0

- Expected
+ Received

- 1
+ 0

 ❯ tests/engine/unit/segments/segment_evaluators.test.ts:310:24
    308| 
    309|         const result = getIdentitySegments(context);
    310|         expect(result).toHaveLength(1);
       |                        ^
    311|         expect(result[0].name).toBe('matching_segment');
    312|     });

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 FAIL  tests/engine/unit/segments/segment_evaluators.test.ts > getContextValue > returns correct value for path $.identity.identifier
AssertionError: expected undefined to be 'user@example.com' // Object.is equality

- Expected: 
"user@example.com"

+ Received: 
undefined

 ❯ tests/engine/unit/segments/segment_evaluators.test.ts:369:24
    367|     ])('returns correct value for path %s', (jsonPath, expected) => {
    368|         const result = getContextValue(jsonPath, mockContext);
    369|         expect(result).toBe(expected);
       |                        ^
    370|     });
    371| 

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 FAIL  tests/engine/unit/segments/segment_evaluators.test.ts > getContextValue > returns correct value for path $.environment.name
AssertionError: expected undefined to be 'Test Environment' // Object.is equality

- Expected: 
"Test Environment"

+ Received: 
undefined

 ❯ tests/engine/unit/segments/segment_evaluators.test.ts:369:24
    367|     ])('returns correct value for path %s', (jsonPath, expected) => {
    368|         const result = getContextValue(jsonPath, mockContext);
    369|         expect(result).toBe(expected);
       |                        ^
    370|     });
    371| 

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 FAIL  tests/engine/unit/segments/segment_evaluators.test.ts > getContextValue > returns correct value for path $.environment.key
AssertionError: expected undefined to be 'test-env-key' // Object.is equality

- Expected: 
"test-env-key"

+ Received: 
undefined

 ❯ tests/engine/unit/segments/segment_evaluators.test.ts:369:24
    367|     ])('returns correct value for path %s', (jsonPath, expected) => {
    368|         const result = getContextValue(jsonPath, mockContext);
    369|         expect(result).toBe(expected);
       |                        ^
    370|     });
    371| 

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[khvn26]

Looks solid to me — will appreciate having an issue, or multiple issues, to fix the newly found problematic tests later.