CodeGraph/docs
Section 4.3

Impact Analysis (Upstream)

Calculates the complete blast radius of modifying a file or symbol by walking incoming structural relationships backward.

Source: server/src/analytics/impact/ImpactAnalyzer.ts

Upstream Reachability Semantics

In CodeGraph, an edge A --[calls]--> B means A calls B. Therefore, if an engineer changes B, the entity directly affected is A.

The ImpactAnalyzer traverses the graph with direction: "incoming" across the 5 structural relationship kinds:

server/src/analytics/impact/ImpactAnalyzer.ts
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export class ImpactAnalyzer {
    constructor(private readonly traversal: GraphTraversal) {}

    analyze(sourceNodeId: string, options: ImpactAnalysisOptions = {}): ImpactAnalysisResult {
        const traversalResult = this.traversal.traverse(sourceNodeId, {
            direction: "incoming",
            relationshipKinds: [
                "calls",
                "imports",
                "extends",
                "implements",
                "instantiates",
            ],
            maxDepth: options.maxDepth,
        });

        return {
            sourceNodeId,
            impactedNodeIds: traversalResult.nodes,
            depthByNode: traversalResult.depthByNode,
        };
    }
}

Interpreting Hop Depth

  • Depth 1: Direct consumers (immediate callers, direct file importers, direct subclasses).
  • Depth 2: Transitive consumers (callers of callers).
  • Depth N: Distant upstream modules affected by transitive dependency chains.
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4.2 Graph Traversal Primitive
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4.4 Dependency Analysis (Downstream)