Increase mail module test coverage to 70%+ with focused unit tests

[Copilot]

• Review latest new PR comments and identify actionable changes
• Check recent CI/workflow failures for relevance
• Run baseline mail tests before changes
• Restore non-requested mock.MatchedBy usages in mail tests
• Keep only the requested AnythingOfType simplification for bind callback matcher
• Run targeted mail tests and gofmt
• Run automated code review and security scan
• Reply to new actionable comments with commit hash

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Task 1.3: Mail Module - Increase test coverage from 42.26% to 70%</issue_title>
<issue_description>Parent Issue: goravel/goravel#43
Priority: 1
Current Coverage: 42.26% (393/930 lines covered, 499 missed)
Target Coverage: 70%
Estimated Impact: +2.5% overall coverage

Focus Areas

• Email sending with different drivers
• Attachment handling
• Template rendering
• Queue integration

Implementation Repository

goravel/framework - mail module</issue_description>

Comments on the Issue (you are @copilot in this section)

@hwbrzzl Closing - creating as sub-tasks in goravel/goravel#43 instead

• Fixes Task 1.3: Mail Module - Increase test coverage from 42.26% to 70% goravel#886

---

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.18%. Comparing base (29a6104) to head (6fab0aa).
⚠️ Report is 5 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1386      +/-   ##
==========================================
+ Coverage   69.40%   71.18%   +1.78%     
==========================================
  Files         292      292              
  Lines       19563    19564       +1     
==========================================
+ Hits        13578    13927     +349     
+ Misses       5403     5054     -349     
- Partials      582      583       +1     

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[hwbrzzl]

Thanks for improving test coverage! I've added some suggestions for optimization and best practices.

[hwbrzzl]

Optimization: Consider using t.Parallel() for these subtests since they're independent. This would speed up test execution:

t.Run("valid key lengths", func(t *testing.T) {
    t.Parallel()
    // ...

[hwbrzzl]

Best Practice: Consider using more descriptive test data or constants. For example:

const (
    testKeyAES128 = "1234567890123456" // 16 bytes
    testKeyAES192 = "123456789012345678901234" // 24 bytes
    testKeyAES256 = "12345678901234567890123456789012" // 32 bytes
)

This makes the test more readable and the key lengths more obvious.

[hwbrzzl]

Code Quality: The RuntimeMode manipulation pattern could be extracted into a test helper if used elsewhere. Consider:

func setRuntimeMode(t *testing.T, mode int) {
    original := support.RuntimeMode
    support.RuntimeMode = mode
    t.Cleanup(func() { support.RuntimeMode = original })
}

Then use: setRuntimeMode(t, support.RuntimeArtisan)

[hwbrzzl]

Potential Issue: This test creates an AES instance with an invalid key but doesn't verify the specific error. The actual error from aes.NewCipher() could be more specific. Consider asserting the error message contains expected text to ensure proper error propagation.

[hwbrzzl]

Code Duplication: The 32-byte key []byte("11111111111111111111111111111111") is repeated multiple times. Consider extracting this into a package-level constant or test helper:

var testValidKey32 = []byte("11111111111111111111111111111111")

func newTestAES(t *testing.T) *AES {
    return &AES{
        json: json.New(),
        key:  testValidKey32,
    }
}

[hwbrzzl]

Test Coverage: This test uses "e30=" (base64 for {}), which is clever but limited. Consider adding more comprehensive error path tests:

• Invalid base64 input (should fail in DecodeString)
• Valid base64 but malformed JSON (should fail in Unmarshal)
• Valid JSON but missing iv or value keys (already covered in source but not tested here)

These edge cases would provide better coverage of DecryptString error handling.

[hwbrzzl]

Test Quality: Consider also testing:

• Empty string encryption/decryption
• Very large strings (performance/buffer handling)
• Strings with special characters, unicode, emojis
• Binary data edge cases

This would ensure the encryption/decryption is robust for real-world use cases.

[hwbrzzl]

Performance optimization: The assertion assert.Same(t, instance, chained) is good, but consider adding a comment explaining that builder methods return the same instance for method chaining (fluent interface pattern). This makes the design decision explicit for future maintainers.

[Copilot]

Updated in 42bfe07: added a clarifying comment at the fluent-chain assertion to document that builder methods should return the same cloned instance.

[hwbrzzl]

Potential issue: The test verifies specific arguments at indices 0, 1, 3, 5, 8, and 9, but does not validate args[0][2], args[0][4], args[0][6], and args[0][7]. Consider adding assertions for all 10 arguments to ensure complete test coverage, or document why certain indices are skipped.

[Copilot]

Updated in 42bfe07: the queue argument test now validates all 10 packed arguments, including indices 2, 4, 6, and 7.

[hwbrzzl]

Code quality: Consider using assert.ErrorContains(t, err, "unsupported") or a more specific error check instead of just assert.Error(t, err). This makes the test more robust and clearly documents what error is expected.

[Copilot]

Updated in 42bfe07: the unsupported-driver branch now uses assert.ErrorContains(..., "not supported") for a more specific expectation.

[hwbrzzl]

Best practice: This test could be more specific about the expected error. Consider using assert.ErrorContains(t, err, "attachment") or checking for a file-not-found error to make the test intention clearer and easier to debug if it fails.

[Copilot]

Updated in 42bfe07: the attachment error test now checks assert.ErrorIs(err, os.ErrNotExist) to make the failure expectation explicit.

[hwbrzzl]

Code quality & readability: The nested callback testing could be refactored for better maintainability. Consider extracting each scenario (withoutConfig, withoutQueue, withAll) into separate subtests using t.Run(). This would improve readability, make test failures easier to identify, and allow running specific scenarios in isolation.

[Copilot]

Updated in 42bfe07: refactored the nested Register callback scenarios into t.Run(...) subtests (without config, without queue, with config and queue) for readability and isolation.

[hwbrzzl]

Test completeness: Consider adding edge case tests for better coverage: 1) calling OnConnection() or OnQueue() multiple times to verify the last value wins, 2) calling methods with empty strings, and 3) verifying idempotency. This would ensure the Queue builder behaves correctly in all scenarios.

[Copilot]

Updated in 42bfe07: expanded TestQueueMail with edge-case subtests for repeated setters (last value wins) and empty-string inputs.

[hwbrzzl]

@copilot There are some comments, but they may not all be correct. Check and fix them if needed.

[Copilot]

@copilot There are some comments, but they may not all be correct. Check and fix them if needed.

Reviewed the actionable comments and applied the relevant mail-test fixes in 42bfe07. I also re-ran go test ./mail, then code review and CodeQL checks (no findings).

[hwbrzzl]

@copilot Fix the comments below.

[hwbrzzl]

Merge this file into mail/application_test.go.

[Copilot]

Done in 3c5f2ba: merged the unit coverage tests into mail/application_test.go and removed mail/application_unit_test.go. No UI changes (test-only update).

[hwbrzzl]

Use mock.AnythingOfType instead of mock.Anything.

[Copilot]

Updated in 0bd319d: replaced mock.Anything with typed mock.MatchedBy(...) matchers for template render arguments. No UI changes (test-only update).

[hwbrzzl]

Don't use mock.Anything

[Copilot]

Updated in 0bd319d: removed mock.Anything in the queue job expectation and switched to typed matchers that also validate the expected job signature. No UI changes (test-only update).

[Copilot]

@copilot Fix the comments below.

Applied the requested fixes in 3c5f2ba and 0bd319d, then re-ran go test ./mail, code review, and CodeQL successfully. No UI changes (test-only update).

[hwbrzzl]

@copilot

[hwbrzzl]

Use mock.AnythingOfType instead of mock.MatchedBy, use any instead of interface{}, optimize other code as well.

[Copilot]

Updated in d865689 (plus e3db6f2/54bc410): switched the requested matcher sites to mock.AnythingOfType, replaced touched callback signatures with any, and aligned related expectations in mail/application_test.go. No UI changes (test-only), so no screenshot is applicable.

[Copilot]

@copilot

Addressed the latest requested test updates in d865689/e3db6f2/54bc410 and re-ran go test ./mail, code review, and CodeQL successfully. No UI changes (test-only), so no screenshot is applicable.

[hwbrzzl]

@copilot I mean the code below is unnecessary,

mock.MatchedBy(func(callback interface{}) bool {
			_, ok := callback.(func(contractsfoundation.Application) (interface{}, error))
			return ok
		}),

not others like:

mock.MatchedBy(matchWithID)

mock.MatchedBy(func(job contractsqueue.Job) bool { return job != nil && job.Signature() == "goravel_send_mail_job" }),
		mock.MatchedBy(func(args []contractsqueue.Arg) bool { return len(args) == 10 }),
	).

[Copilot]

Updated in 6fab0aa: restored the mock.MatchedBy(matchWithID) and queue mock.MatchedBy(...) matchers, and kept only the bind-callback simplification. No UI changes (test-only), so there is no screenshot to provide.