Add MQTT location response tests

[augard]

Summary

• add VehicleMQTTLocationResponseTests to cover merged timestamp decoding
• verify valid timestamp parsing yields expected UTC components even when location is null
• ensure invalid timestamp formats throw and round-trip formatter via MergedDateFormatter

Testing

• Not run (not requested)

[github-actions]

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[augmentcode]

🤖 Augment PR Summary

Summary: Adds test coverage for MQTT location responses and merged timestamp decoding.

Changes:

• Add VehicleMQTTLocationResponseTests to exercise latestUpdateTime parsing (yyyyMMddHHmmss) and Location: null decoding.
• Assert the parsed Date matches expected UTC components.
• Ensure invalid timestamp formats throw and validate MergedDateFormatter round-trip behavior.

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[augmentcode]

Review completed. 2 suggestions posted.

Comment augment review to trigger a new review at any time.

[augmentcode]

This XCTAssertThrowsError will pass for any decoding failure, not specifically an invalid merged timestamp. Consider also asserting the thrown error is DateValue<MergedDateFormatter>.ParsingError.invalidString (or that its codingPath points at latestUpdateTime) to ensure the test is actually covering timestamp parsing.

Severity: low

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[augmentcode]

XCTAssertNotNil(date) doesn’t stop execution, so the subsequent date! can crash the test and hide the real assertion failure. Consider using XCTUnwrap(date) (or guard let) to keep failures reported as test failures instead of a runtime crash.

Severity: low

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[Copilot]

Pull request overview

Adds a new XCTest suite to validate decoding of MQTT “merged” timestamp strings for VehicleMQTTLocationResponse, including behavior when the nested Location payload is null.

Changes:

• Add coverage for decoding a valid latestUpdateTime merged timestamp and asserting UTC date components.
• Add a negative test ensuring invalid merged timestamp strings fail decoding.
• Add a MergedDateFormatter round-trip test (string → date → string).

---

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[Copilot]

Avoid forcing unwrap on TimeZone(secondsFromGMT: 0) in tests; if it ever returns nil this will crash the test process instead of producing a clean failure. Prefer using TimeZone.gmt (if available) or guard let tz = TimeZone(secondsFromGMT: 0) else { XCTFail(...); return }.

Suggested change

	utc.timeZone = TimeZone(secondsFromGMT: 0)!
	utc.timeZone = .gmt

[Copilot]

This test force-unwraps date after XCTAssertNotNil(date), which can still produce a crash with a less-informative failure if the assertion is skipped/continues. Prefer guard let date else { XCTFail("..."); return } and then use the non-optional date for the round-trip assertion.

Suggested change

	let date = formatter.date(from: source)
	XCTAssertNotNil(date)
	XCTAssertEqual(formatter.string(from: date!), source)
	guard let date = formatter.date(from: source) else {
	XCTFail("Expected MergedDateFormatter to produce a date from valid source string")
	return
	}
	XCTAssertEqual(formatter.string(from: date), source)

[Copilot]

XCTAssertThrowsError here only verifies that decoding fails, but not that it fails for the expected reason (invalid merged timestamp). Consider asserting the thrown error is DateValue<MergedDateFormatter>.ParsingError.invalidString (or at least that it contains the offending string/codingPath) so the test won’t pass if decoding starts failing for an unrelated reason.

Suggested change

	XCTAssertThrowsError(try JSONDecoder().decode(VehicleMQTTLocationResponse.self, from: data))
	XCTAssertThrowsError(try JSONDecoder().decode(VehicleMQTTLocationResponse.self, from: data)) { error in
	// Ensure the error comes from the merged date parsing and relates to the invalid timestamp
	if let parsingError = error as? DateValue<MergedDateFormatter>.ParsingError {
	let description = String(describing: parsingError)
	XCTAssertTrue(
	description.contains("2025-09-01T14:27:33Z"),
	"Expected parsing error to reference invalid timestamp, got: \(description)"
	)
	} else {
	XCTFail("Expected DateValue<MergedDateFormatter>.ParsingError, got \(type(of: error)): \(error)")
	}
	}