From 9c66c7865010cec45e7d49019aa344d0774ec7e8 Mon Sep 17 00:00:00 2001
From: Teddy Wing
Date: Thu, 18 May 2023 02:02:25 +0200
Subject: Ignore shadowed variables

In order to ignore shadowed variables, we first build a list of all
local assignments in the closure, and ignore any ident in that list.
---
 gocapturedrefrace.go | 89 ++++++++++++++++++++++++++++++----------------------
 1 file changed, 52 insertions(+), 37 deletions(-)

diff --git a/gocapturedrefrace.go b/gocapturedrefrace.go
index cdc6486..3f776e0 100644
--- a/gocapturedrefrace.go
+++ b/gocapturedrefrace.go
@@ -85,13 +85,12 @@ func checkClosure(pass *analysis.Pass, funcLit *ast.FuncLit) {
 	// Get the closure's scope.
 	funcScope := pass.TypesInfo.Scopes[funcLit.Type]
 
+	localAssignments := checkShadowing(pass, funcLit)
+	fmt.Printf("localAssignments: %#v\n", localAssignments)
+
 	ast.Inspect(
 		funcLit,
 		func(node ast.Node) bool {
-			if isShadowingDeclaration(pass, node, funcScope) {
-				return true
-			}
-
 			ident, ok := node.(*ast.Ident)
 			if !ok {
 				return true
@@ -101,6 +100,13 @@ func checkClosure(pass *analysis.Pass, funcLit *ast.FuncLit) {
 				return true
 			}
 
+			// Ignore shadowed variables.
+			for _, localAssignmentIdent := range localAssignments {
+				if ident == localAssignmentIdent {
+					return true
+				}
+			}
+
 			// Find out whether `ident` was defined in an outer scope.
 			scope, scopeObj := funcScope.LookupParent(ident.Name, ident.NamePos)
 
@@ -140,43 +146,52 @@ func checkClosure(pass *analysis.Pass, funcLit *ast.FuncLit) {
 }
 
 // TODO: doc
-func isShadowingDeclaration(
+func checkShadowing(
 	pass *analysis.Pass,
-	node ast.Node,
-	funcScope *types.Scope,
-) bool {
+	funcLit *ast.FuncLit,
+	// funcScope *types.Scope,
+) (localAssignments []*ast.Ident) {
 	// TODO: Plan: Change this function to checkShadowing. Call ast.Inspect and build a list of local assignments in the closure. Then in checkClosure, ignore objects in the local assignments list.
 
-	assignStmt, ok := node.(*ast.AssignStmt)
-	if !ok {
-		return false
-	}
+	localAssignments = []*ast.Ident{}
 
-	if assignStmt.Tok != token.DEFINE {
-		return false
-	}
+	ast.Inspect(
+		funcLit,
+		func(node ast.Node) bool {
+			assignStmt, ok := node.(*ast.AssignStmt)
+			if !ok {
+				return true
+			}
 
-	for _, lhs := range assignStmt.Lhs {
-		ident, ok := lhs.(*ast.Ident)
-		if !ok {
-			return false
-		}
-		fmt.Printf("assignStmt: %#v\n", ident)
-
-		if ident == nil {
-			return false
-		}
-
-		return true
-
-		// TODO: If ident is in parent, ignore it an move on.
-		// scope, scopeObj := funcScope.LookupParent(ident.Name, ident.NamePos)
-		//
-		// // Identifier is local to the closure.
-		// if scope == nil && scopeObj == nil {
-		// 	return
-		// }
-	}
+			if assignStmt.Tok != token.DEFINE {
+				return true
+			}
+
+			for _, lhs := range assignStmt.Lhs {
+				ident, ok := lhs.(*ast.Ident)
+				if !ok {
+					return true
+				}
+				fmt.Printf("assignStmt: %#v\n", ident)
+
+				if ident == nil {
+					return true
+				}
+
+				localAssignments = append(localAssignments, ident)
+
+				// TODO: If ident is in parent, ignore it an move on.
+				// scope, scopeObj := funcScope.LookupParent(ident.Name, ident.NamePos)
+				//
+				// // Identifier is local to the closure.
+				// if scope == nil && scopeObj == nil {
+				// 	return
+				// }
+			}
+
+			return true
+		},
+	)
 
-	return false
+	return localAssignments
 }
-- 
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