🎨 Add module level guard for string variables

Author: savannahostrowski

src/core/extractors.ts

@@ -65,16 +65,27 @@ function collectNodesByType(node: Node, type: string, results: Node[]): void {
  * Collects string variable assignments from the AST for path resolution.
  * Handles simple assignments like `WEBHOOK_PATH = "/webhook"`.
  *
+ * Only module-level assignments are collected — function/class-local variables
+ * are skipped to prevent shadowing module-level constants with the same name.
+ *
  * Examples:
  *   WEBHOOK_PATH = "/webhook"  -> Map { "WEBHOOK_PATH" => "/webhook" }
  *   BASE = "/api"              -> Map { "BASE" => "/api" }
  *   settings.PREFIX = "/api"   -> (skipped, not a simple identifier)
+ *   def f(): BASE = "/local"   -> (skipped, inside function)
  */
 export function collectStringVariables(rootNode: Node): Map<string, string> {
   const variables = new Map<string, string>()
   const assignmentNodes = findNodesByType(rootNode, "assignment")
 
   for (const assign of assignmentNodes) {
+    if (
+      hasAncestor(assign, "function_definition") ||
+      hasAncestor(assign, "class_definition")
+    ) {
+      continue
+    }
+
     const left = assign.childForFieldName("left")
     const right = assign.childForFieldName("right")
     if (

src/test/core/extractors.test.ts

@@ -1,6 +1,7 @@
 import * as assert from "node:assert"
 import {
   collectRecognizedNames,
+  collectStringVariables,
   decoratorExtractor,
   extractPathFromNode,
   extractStringValue,
@@ -863,6 +864,53 @@ router = f.APIRouter(prefix="/items")
     })
   })
 
+  suite("collectStringVariables", () => {
+    test("collects module-level string assignments", () => {
+      const code = `
+PREFIX = "/api"
+VERSION = "/v1"
+`
+      const tree = parse(code)
+      const vars = collectStringVariables(tree.rootNode)
+      assert.strictEqual(vars.get("PREFIX"), "/api")
+      assert.strictEqual(vars.get("VERSION"), "/v1")
+    })
+
+    test("ignores function-local variables", () => {
+      const code = `
+PREFIX = "/api"
+
+def handler():
+    PREFIX = "/local"
+`
+      const tree = parse(code)
+      const vars = collectStringVariables(tree.rootNode)
+      assert.strictEqual(vars.get("PREFIX"), "/api")
+    })
+
+    test("ignores class-level variables", () => {
+      const code = `
+PREFIX = "/api"
+
+class Config:
+    PREFIX = "/class-level"
+`
+      const tree = parse(code)
+      const vars = collectStringVariables(tree.rootNode)
+      assert.strictEqual(vars.get("PREFIX"), "/api")
+    })
+
+    test("ignores non-string assignments", () => {
+      const code = `
+COUNT = 42
+FLAG = True
+`
+      const tree = parse(code)
+      const vars = collectStringVariables(tree.rootNode)
+      assert.strictEqual(vars.size, 0)
+    })
+  })
+
   suite("extractStringValue", () => {
     test("returns null for non-string node", () => {
       const code = "x = 42"