plugin-common

@codegraph/plugin-common

Shared utilities for all CodeGraph language plugins. Eliminates duplicated AST traversal, ID generation, and grammar helper functions across 6+ language plugins.

API

Complexity Analysis

Language-agnostic complexity metrics computed via tree-sitter AST traversal. Covers TypeScript, Python, Java, Go, Rust, C#, PHP, and more through a unified node-type mapping.

• calculateComplexity(node) -- Returns all three metrics in a single AST walk:
  • cyclomatic: 1 + decision points + logical operators
  • cognitive: flow breaks + nesting-level penalties
  • nestingDepth: maximum nesting depth of control structures
• calculateCyclomatic(node) -- Cyclomatic complexity only.
• calculateCognitive(node) -- Cognitive complexity only.
• calculateNestingDepth(node) -- Max nesting depth only.
• classifyComplexity(metrics) -- Returns 'low' | 'medium' | 'high' | 'critical' based on thresholds.
• COMPLEXITY_THRESHOLDS -- Configurable thresholds (cyclomatic: 10/20/50, cognitive: 15/30, nesting: 4/6).

Decision points recognized: if, for, while, switch/match, catch/except, ternary, logical operators (&&, ||, ??, and, or), plus language-specific variants for Rust expressions, Go select/defer, Python elif/with, and Java/C# switch labels.

AST Helpers

• findNodesOfType(root, types) -- Recursively finds all AST nodes matching the given type names. Used by every language plugin for entity extraction.

Entity ID Generation

• generateEntityId(filePath, type, name, line) -- Deterministic entity ID in the format filePath:type:name:line.

Grammar Helpers

• createGrammarHelpers(extensionToGrammar) -- Creates grammar lookup helpers from an extension-to-grammar mapping. Returns:
  • getGrammarForExtension(ext) -- Lookup grammar by file extension.
  • getSupportedExtensions() -- List all supported extensions.
  • isSupported(ext) -- Check if an extension is supported.

Types

• ComplexityMetrics -- { cyclomatic: number; cognitive: number; nestingDepth: number }
• GrammarHelpers -- Return type of createGrammarHelpers

Usage

import {
  calculateComplexity,
  findNodesOfType,
  generateEntityId,
  createGrammarHelpers,
} from '@codegraph/plugin-common';