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Code Quality Analyzer

The code quality analyzer tracks complexity, Halstead metrics, comment quality, and cohesion across Git history. For each commit, it runs four static analyzers on UAST-parsed changed files and produces per-file quality metrics.

Quick Start

codefang run -a history/quality .

Requires UAST

The quality analyzer needs UAST support to parse source code. It is automatically enabled when the UAST pipeline is available.

Architecture

The quality analyzer follows the TC/Aggregator pattern:

  1. Consume phase: For each commit, Consume() runs four static analyzers (complexity, Halstead, comments, cohesion) on each changed file's UAST, returning per-file metrics as a TC{Data: *TickQuality}. The analyzer retains no per-commit state.
  2. Aggregation phase: A quality.Aggregator collects TCs, merges TickQuality data by time bucket (tick), and produces TICK results.
  3. Serialization phase: SerializeTICKs() converts aggregated TICKs into JSON, YAML, binary, or HTML plot output via ComputeAllMetrics().

This separation enables streaming output, budget-aware memory spilling, and decoupled aggregation.

What It Measures

Per-File Metrics

For each changed file in a commit, the analyzer computes:

Category Metrics
Complexity Cyclomatic complexity, cognitive complexity, max single-function complexity, function count
Halstead Volume, effort, delivered bugs
Comments Overall comment score, documentation coverage
Cohesion Cohesion score

Statistical Aggregation

Per-tick statistics are computed from per-file arrays:

  • Mean, median, P95, max for complexity and Halstead volume
  • Sum for delivered bugs and Halstead volume
  • Min for comment score and cohesion (worst-case tracking)
  • Total files analyzed and functions counted

Output Formats

Format Flag Description
JSON --format json ComputedMetrics with time_series and aggregate fields
YAML --format yaml Same structure as JSON
Plot --format plot HTML page with complexity and Halstead charts plus summary stats
Binary --format binary Compact binary envelope for programmatic consumption

Configuration

The quality analyzer has no configurable options. It uses the UAST pipeline's language detection and parsing configuration.