Add encryption compatibility tests

[RyanGarfinkel]

What does this PR do?

This PR adds additional compatibility tests for the encryption feature: insert, update, delete, find, null/missing values, plaintext type, incorrect type, oversized, and nested values. Originally, there was only one, basic smoke test which only covered basic functionality. The tests were then verified in a MongoDB environment. A fixture was also created to be used by each of the additional tests.

Why was this PR needed?

This PR Closes #537, which required adding additional test coverage to the encryption feature. Initially, this operator only had one smoke test, which tested basic functionality. This PR addresses the issue of missing a more extensive test suite to ensure the encryption feature properly handles CRUD operations, null/missing values, oversized values, nested, and incorrect types of values.

What are the relevant issue numbers?

Closes #537

Screenshots

Image of tests passing. Command: ```python -m pytest compatibility/tests/system/security/encryption --connection-string "mongodb://localhost:27018/?directConnection=true" --engine-name mongodb -v```

Does this PR meet the acceptance criteria?

• Tests added for new/changed behavior
• All tests passing
• Follows project style guide
• No breaking changes introduced

[Copilot]

Pull request overview

This PR expands the compatibility test suite for Queryable Encryption by introducing shared QE-collection fixtures and adding focused tests covering CRUD enforcement, query/aggregation behavior, and edge cases (nested paths, large plaintext values, multi-document inserts). This aligns with Issue #537’s requirement for comprehensive QE compatibility coverage beyond the existing smoke test.

Changes:

• Added reusable fixtures for creating/dropping Queryable Encryption collections with different encrypted-field shapes.
• Added CRUD-focused tests validating that plaintext writes to encrypted paths are rejected while missing fields remain acceptable.
• Added query/aggregation and edge-case tests to ensure raw queries execute normally and that nested/large/multi-doc cases behave consistently.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
documentdb_tests/compatibility/tests/system/security/encryption/utils/qe_collections.py	Adds shared fixtures to create QE collections with single, multi-field, and nested encrypted paths.
documentdb_tests/compatibility/tests/system/security/encryption/utils/init.py	Ensures the new utils directory is a Python package for imports/fixture re-exporting.
documentdb_tests/compatibility/tests/system/security/encryption/conftest.py	Re-exports QE fixtures so all tests in the directory can use them without per-file imports.
documentdb_tests/compatibility/tests/system/security/encryption/test_encryption_crud.py	Adds CRUD validation tests ensuring plaintext writes to encrypted paths fail and delete/missing-field behaviors succeed.
documentdb_tests/compatibility/tests/system/security/encryption/test_encryption_query.py	Adds tests ensuring raw find/aggregate expressions referencing encrypted fields execute without encryption-specific errors.
documentdb_tests/compatibility/tests/system/security/encryption/test_encryption_edge_cases.py	Adds edge-case tests for nested encrypted paths, large plaintext rejection, multi-doc inserts, and explain compatibility.

[documentdb-triage-tool]

🤖 Auto-triaged by documentdb-triage-tool.

Applied: compatibility test, enhancement
Project fields suggested: Component test-coverage · Priority P2 · Effort L · Status Needs Review
Confidence: 0.90 (mixed)

Reasoning

component from path globs (test-coverage); effort from diff stats (412+0 LOC, 6 files); LLM: Adds expanded compatibility test coverage for the encryption feature (CRUD, null/missing, oversized, nested, incorrect types), closing a tracked issue for insufficient test coverage.

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