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Complexity analyzer reference

The complexity analyzer measures three dimensions of code complexity from source code: cyclomatic complexity, cognitive complexity, and nesting depth. It operates on the UAST representation of your source files.

For the conceptual model — what each metric means and how cyclomatic and cognitive complexity differ — see Understanding complexity metrics. To run it, see the Quick start.

Configuration options

The complexity analyzer uses the UAST directly and has no analyzer-specific configuration options. Language support is determined by the UAST parser.

Option Type Default Description
(none) -- -- Uses UAST; no analyzer-specific config

Example output

{
  "function_complexity": [
    {
      "name": "processFile",
      "source_file": "cmd/server/main.go",
      "language": "go",
      "directory": "cmd/server",
      "cyclomatic_complexity": 8,
      "cognitive_complexity": 12,
      "nesting_depth": 3,
      "lines_of_code": 45,
      "complexity_density": 0.178,
      "risk_level": "LOW"
    },
    {
      "name": "validate",
      "source_file": "cmd/server/main.go",
      "language": "go",
      "directory": "cmd/server",
      "cyclomatic_complexity": 15,
      "cognitive_complexity": 22,
      "nesting_depth": 5,
      "lines_of_code": 80,
      "complexity_density": 0.188,
      "risk_level": "MEDIUM"
    }
  ],
  "high_risk_functions": [
    {
      "name": "validate",
      "source_file": "cmd/server/main.go",
      "language": "go",
      "directory": "cmd/server",
      "cyclomatic_complexity": 15,
      "cognitive_complexity": 22,
      "risk_level": "MEDIUM",
      "issues": ["High cyclomatic complexity", "Deep nesting"]
    }
  ],
  "distribution": {
    "simple": 180,
    "moderate": 25,
    "complex": 7
  },
  "aggregate": {
    "total_functions": 212,
    "average_complexity": 3.2,
    "max_complexity": 15,
    "health_score": 78.5,
    "message": "Fair complexity - some functions could be simplified"
  }
}

Each function record includes source_file, language, and directory for file-level joins and DWH aggregation.

Complexity Analysis
  processFile  (main.go:42)   cyclomatic=8   cognitive=12  nesting=3
  validate     (main.go:105)  cyclomatic=15  cognitive=22  nesting=5

Summary: 2 functions, avg cyclomatic=11.5, max nesting=5

Terminal output (readable risk triage)

Top issue rows include all core complexity dimensions in one compact value:

  • CC=<cyclomatic> | Cog=<cognitive> | Nest=<nesting>

Example:

BoolChain      CC=5 | Cog=3 | Nest=1
NestedIf       CC=4 | Cog=6 | Nest=3

Issues are sorted numerically by cyclomatic complexity (then cognitive, then nesting) so the highest-risk functions consistently appear first.

Plot output (fast visual scanning)

The plot output emphasizes fast interpretation for code-review and planning:

  • Scatter view includes explicit cyclomatic/cognitive warning guide lines.
  • Bubble size maps to nesting depth to preserve one-glance hotspot detection.
  • Bar and pie views keep the same threshold semantics as terminal output.

See also