Code Metrics analysis

[powercode]

Hi!

Would having a set of rules for code complexity be a good idea?

Like the number of lines in a method, the number of blocks, the depth of block nesting, etc?

[bergmeister]

I guess so. But from usability concept I guess most people would expect output like a report.
For PSScriptAnalyzer the output of a rule is a diagnosticrecord so I guess a user would have to define a limit before a diagnosticrecord is emitted.

[SamErde]

I like the idea of measuring code complexity. Is this something that can be reasonably baked into PSScriptAnalyzer with a truly objective set of rules? (For example, the Halstead Volume as described by Codacy.)

[powercode]

We can establish sensible defaults, with two thresholds per metric (e.g., WarningThreshold and ErrorThreshold).

The analysis would then result in one or more DiagnosticRecord, and we could have settings for changing the default thresholds.

Halstead Volume is a candidate, but I think we should strive for
Maintainability Index = 171 - 5.2 * ln(Halstead Volume) - 0.23 * (Cyclomatic Complexity) - 16.2 * ln(Lines of Code)

The constants here are tuned for the C programming language, and are unlikely to be good for PowerShell.

[powercode]

Whatever algorithm we choose, we need to empirically calibrate it, adjusting the weights, to ensure that the result accurately reflects its maintainability.