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Code Analysis with PHP Metrics

Code Analysis with PHP Metrics

Chris Gmyr

July 27, 2017

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  1. Code Analysis
    PHP Metrics

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  2. Presented by
    Chris Gmyr

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  3. Installation
    composer global require phpmetrics/phpmetrics

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  4. Generate Report
    phpmetrics --report-html=myreport /path/of/src

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  5. Laravel
    git clone [email protected]:laravel/laravel.git
    phpmetrics --report-html=laravel_metrics laravel

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  9. What Are We Going to Learn?
    4 Maintainability
    4 Violations
    4 Complexity
    4 Relationships

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  10. But First,
    Some Vocabulary!

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  11. Cyclomatic Complexity
    The cyclomatic complexity of a section of source code is the number of
    linearly independent paths within it.
    4 If the source code contained no control flow statements (conditionals
    or decision points), the complexity would be 1.
    4 One IF statement = two paths through the code, complexity would be 2.
    4 Two nested single-condition IFs, or one IF with two conditions, would
    produce a complexity of 3.

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  13. More Conditionals & Statements = More Complex

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  14. Lower Score is Better!

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  15. Halstead Complexity Measures
    Observation that metrics of the software should
    reflect the implementation or expression of algorithms
    in different languages, but be independent of their
    execution on a specific platform.

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  17. Lower Score is Better!

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  18. Maintainability Index
    Provides a score between 0 to 118. Halstead's metrics, LOC and
    Cyclomatic complexity number.
    General scores:
    4 <64: low maintainability. The project has probably technical debt.
    4 65-84: medium maintainability. The project has problems, but
    nothing really serious.
    4 >85: high maintainability. The project is probably good.

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  19. Higher Score is Better!

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  20. Let's Explore!

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  35. Violations

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  38. Size & Volume

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  40. Complexity & Defects

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  42. Object Oriented Metrics

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  44. Object Relations

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  46. Coupling

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  49. Takeaways
    1. More Classes
    2. Smaller Classes
    3. Simpler Classes
    4. Loosely Coupled Classes

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  50. Thank you!

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  51. Say "Hi"!

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