test: improve coverage for builtin/hasher.mbt

[rami3l]

Disclaimer: This PR was generated by an LLM agent as part of an experiment.

Summary

coverage of `builtin/hasher.mbt`: 69.4% -> 75.0%

[peter-jerry-ye-code-review]

‼️ This code review is generated by a bot. Please verify the content before trusting it.

Looking at the git diff, here are the potential issues I notice:

1. Inconsistent assertion style: The code uses both inspect!() and assert_eq!() macros for testing equality. In "combine_unit" test, it uses inspect!() while in "combine_bool" test, it uses assert_eq!(). For consistency and maintainability, it would be better to stick to one assertion style throughout the test file.

2. Variable naming: In the "combine_bool" test, the variables are named hash1, hash2, hash3, hash4, which are not very descriptive. More meaningful names like true_hash, one_hash, false_hash, zero_hash would better convey their purpose and make the test more readable.

3. Test organization: The new tests are added at the end of the file with a gap (empty line) between the existing tests. For better organization and readability, it might be better to group related tests together without unnecessary spacing.

These aren't critical issues that would cause bugs, but addressing them would improve code quality and maintainability.

[coveralls]

Pull Request Test Coverage Report for Build 5024

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.03%) to 85.04%

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Totals
Change from base Build 5019:	0.03%
Covered Lines:	5224
Relevant Lines:	6143

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💛 - Coveralls