refactor(javascript): share Babel child traversal

src/domain/javascript/javascriptSemanticReturns.ts

@@ -26,7 +26,10 @@ import {
 import { evaluateSemanticExpression } from "./javascriptSemanticValues.js";
 import { range } from "./javascriptStaticAnalysisHelpers.js";
 import { semanticReturnCoverage } from "./javascriptSemanticCoverage.js";
-import { traverseJavaScriptAst } from "./javascriptSemanticTraversal.js";
+import {
+  childNodes,
+  traverseJavaScriptAst,
+} from "./javascriptSemanticTraversal.js";
 
 interface ReturnExpression {
   readonly node: t.Node | null;
@@ -145,15 +148,6 @@ const directReturnExpressions = (callable: t.Node): ReturnExpression[] => {
   return output;
 };
 
-const childNodes = (node: t.Node): t.Node[] =>
-  (t.VISITOR_KEYS[node.type] ?? []).flatMap((key) => {
-    const value: unknown = Reflect.get(node, key);
-    if (t.isNode(value)) return [value];
-    return Array.isArray(value)
-      ? value.filter((item): item is t.Node => t.isNode(item))
-      : [];
-  });
-
 const callableIdsForBinding = (
   binding: JavaScriptSemanticBindingState,
   state: JavaScriptSemanticAnalysisState,

src/domain/javascript/javascriptSemanticTraversal.ts

@@ -50,7 +50,8 @@ interface TraversalFrame {
   nextIndex: number;
 }
 
-const childNodes = (node: t.Node): t.Node[] => {
+/** Return child Babel nodes in visitor-key order. */
+export const childNodes = (node: t.Node): t.Node[] => {
   const keys = t.VISITOR_KEYS[node.type];
   if (keys === undefined) return [];
   const children: t.Node[] = [];

src/domain/referenceSourceImportParsing.ts

@@ -6,6 +6,7 @@ import type {
   Node,
   StringLiteral,
 } from "@babel/types";
+import { traverseJavaScriptAst } from "./javascript/javascriptSemanticTraversal.js";
 import {
   isCallExpression,
   isExportAllDeclaration,
@@ -15,7 +16,6 @@ import {
   isImportDeclaration,
   isImportExpression,
   isMemberExpression,
-  isNode,
   isStringLiteral,
   isTSExternalModuleReference,
   isTSImportEqualsDeclaration,
@@ -201,39 +201,6 @@ const isRequireCallee = (callee: Node | null | undefined): boolean => {
   return false;
 };
 
-const collectModuleExpressions = (
-  node: unknown,
-  targets: Array<CallExpression | ImportExpression>,
-): void => {
-  if (node === null || node === undefined) return;
-  if (typeof node !== "object") return;
-  if (Array.isArray(node)) {
-    for (const item of node) collectModuleExpressions(item, targets);
-    return;
-  }
-  if (!isNode(node)) return;
-  if (isCallExpression(node) || isImportExpression(node)) {
-    targets.push(node);
-  }
-  for (const value of Object.values(node)) {
-    if (
-      value !== null &&
-      value !== undefined &&
-      typeof value === "object" &&
-      !isSourceLocation(value)
-    ) {
-      collectModuleExpressions(value, targets);
-    }
-  }
-};
-
-const isSourceLocation = (value: unknown): boolean =>
-  typeof value === "object" &&
-  value !== null &&
-  "start" in value &&
-  "end" in value &&
-  !("type" in value);
-
 const extractRequireAndDynamicImports = (
   body: readonly Node[],
   from_path: string,
@@ -241,7 +208,12 @@ const extractRequireAndDynamicImports = (
 ): void => {
   const expressions: Array<CallExpression | ImportExpression> = [];
   for (const statement of body)
-    collectModuleExpressions(statement, expressions);
+    traverseJavaScriptAst(statement, {
+      enter: (node) => {
+        if (isCallExpression(node) || isImportExpression(node))
+          expressions.push(node);
+      },
+    });
 
   for (const call of expressions) {
     if (isImportExpression(call)) {