feat: expose ancestor type chain in RuleContext (#197)

src/core/contracts/rule.ts

@@ -41,6 +41,8 @@ export interface RuleContext {
   componentDepth: number;
   maxDepth: number;
   path: string[];
+  /** Ancestor node types from root to parent (excludes current node). */
+  ancestorTypes: string[];
   siblings?: AnalysisNode[] | undefined;
   /** Per-analysis shared state. Created fresh for each analysis run, eliminating module-level mutable state. */
   analysisState: Map<string, unknown>;

src/core/engine/rule-engine.ts

@@ -187,6 +187,7 @@ export class RuleEngine {
       failedRules,
       0,
       [],
+      [],
       0,
       analysisState,
       undefined,
@@ -234,6 +235,7 @@ export class RuleEngine {
     failedRules: RuleFailure[],
     depth: number,
     path: string[],
+    ancestorTypes: string[],
     componentDepth: number,
     analysisState: Map<string, unknown>,
     parent?: AnalysisNode,
@@ -261,6 +263,7 @@ export class RuleEngine {
       componentDepth: currentComponentDepth,
       maxDepth,
       path: nodePath,
+      ancestorTypes,
       siblings,
       analysisState,
     };
@@ -308,6 +311,7 @@ export class RuleEngine {
 
     // Recurse into children
     if (node.children && node.children.length > 0) {
+      const childAncestorTypes = [...ancestorTypes, node.type];
       for (const child of node.children) {
         this.traverseAndCheck(
           child,
@@ -318,6 +322,7 @@ export class RuleEngine {
           failedRules,
           depth + 1,
           nodePath,
+          childAncestorTypes,
           currentComponentDepth + 1,
           analysisState,
           node,

src/core/rules/component/index.ts

@@ -77,14 +77,12 @@ function buildFingerprint(node: AnalysisNode, depth: number): string {
 
 /**
  * Check if the node is inside an INSTANCE subtree.
- * Currently checks immediate parent only — RuleContext does not expose the full
- * ancestor type chain (context.path contains names, not types).
- * TODO: When the engine exposes ancestor types, extend to full chain check.
+ * Walks the full ancestor type chain to detect INSTANCE at any level.
  */
 function isInsideInstance(context: {
-  parent?: AnalysisNode | undefined;
+  ancestorTypes: string[];
 }): boolean {
-  return context.parent?.type === "INSTANCE";
+  return context.ancestorTypes.includes("INSTANCE");
 }
 
 

src/core/rules/component/missing-component.test.ts

@@ -42,6 +42,7 @@ function makeContext(overrides?: Partial<RuleContext>): RuleContext {
     componentDepth: 0,
     maxDepth: 10,
     path: ["Page", "Section"],
+    ancestorTypes: [],
     analysisState,
     ...overrides,
   };
@@ -321,15 +322,16 @@ describe("missing-component — Stage 3: Structure-based repetition", () => {
     const frameB = makeNode({ id: "f:2", children: [childB] });
     const frameC = makeNode({ id: "f:3", children: [childC] });
 
-    const instanceParent: AnalysisNode = {
-      id: "inst:1",
-      name: "MyInstance",
-      type: "INSTANCE",
+    const nestedFrameParent: AnalysisNode = {
+      id: "frame:1",
+      name: "NestedFrame",
+      type: "FRAME",
       visible: true,
     };
 
     const ctx = makeContext({
-      parent: instanceParent,
+      parent: nestedFrameParent,
+      ancestorTypes: ["DOCUMENT", "INSTANCE", "FRAME"],
       siblings: [frameA, frameB, frameC],
     });
 

src/core/rules/rule-exceptions.test.ts

@@ -25,6 +25,7 @@ function makeContext(overrides: Partial<RuleContext> = {}): RuleContext {
     componentDepth: 0,
     maxDepth: 10,
     path: ["Root", "Test"],
+    ancestorTypes: [],
     analysisState: new Map(),
     ...overrides,
   };

src/core/rules/test-helpers.ts

@@ -25,6 +25,7 @@ export function makeContext(overrides?: Partial<RuleContext>): RuleContext {
     componentDepth: 0,
     maxDepth: 10,
     path: ["Page", "Section"],
+    ancestorTypes: [],
     analysisState: new Map(),
     ...overrides,
   };