Update the no-else-return rule

defaultrule/no-else-return-rule.go

@@ -14,9 +14,13 @@ type LintElseRule struct{}
 // Apply applies the rule to given file.
 func (r *LintElseRule) Apply(file *file.File, arguments rule.Arguments) []rule.Failure {
 	var failures []rule.Failure
-	ast.Walk(lintElse(func(failure rule.Failure) {
+
+	onFailure := func(failure rule.Failure) {
 		failures = append(failures, failure)
-	}), file.GetAST())
+	}
+
+	w := lintElse{make(map[*ast.IfStmt]bool), onFailure}
+	ast.Walk(w, file.GetAST())
 	return failures
 }
 
@@ -25,36 +29,47 @@ func (r *LintElseRule) Name() string {
 	return "no-else-return"
 }
 
-type lintElse func(rule.Failure)
+type lintElse struct {
+	ignore    map[*ast.IfStmt]bool
+	onFailure func(rule.Failure)
+}
 
-func (f lintElse) Visit(n ast.Node) ast.Visitor {
-	node, ok := n.(*ast.IfStmt)
-	if ok {
-		if node.Else == nil {
-			return f
-		}
-		if _, ok := node.Else.(*ast.BlockStmt); !ok {
-			// only care about elses without conditions
-			return f
-		}
-		if len(node.Body.List) == 0 {
-			return f
-		}
-		// shortDecl := false // does the if statement have a ":=" initialization statement?
-		if node.Init != nil {
-			if as, ok := node.Init.(*ast.AssignStmt); ok && as.Tok == token.DEFINE {
-				// shortDecl = true
-			}
-		}
-		lastStmt := node.Body.List[len(node.Body.List)-1]
-		if _, ok := lastStmt.(*ast.ReturnStmt); ok {
-			f(rule.Failure{
-				Failure: "if block ends with a return statement, so drop this else and outdent its block",
-				Type:    rule.FailureTypeWarning,
-				Node:    node.Else,
-			})
-			return f
+func (w lintElse) Visit(node ast.Node) ast.Visitor {
+	ifStmt, ok := node.(*ast.IfStmt)
+	if !ok || ifStmt.Else == nil {
+		return w
+	}
+	if w.ignore[ifStmt] {
+		return w
+	}
+	if elseif, ok := ifStmt.Else.(*ast.IfStmt); ok {
+		w.ignore[elseif] = true
+		return w
+	}
+	if _, ok := ifStmt.Else.(*ast.BlockStmt); !ok {
+		// only care about elses without conditions
+		return w
+	}
+	if len(ifStmt.Body.List) == 0 {
+		return w
+	}
+	shortDecl := false // does the if statement have a ":=" initialization statement?
+	if ifStmt.Init != nil {
+		if as, ok := ifStmt.Init.(*ast.AssignStmt); ok && as.Tok == token.DEFINE {
+			shortDecl = true
 		}
 	}
-	return f
+	lastStmt := ifStmt.Body.List[len(ifStmt.Body.List)-1]
+	if _, ok := lastStmt.(*ast.ReturnStmt); ok {
+		extra := ""
+		if shortDecl {
+			extra = " (move short variable declaration to its own line if necessary)"
+		}
+		w.onFailure(rule.Failure{
+			Failure: "if block ends with a return statement, so drop this else and outdent its block" + extra,
+			Type:    rule.FailureTypeWarning,
+			Node:    ifStmt.Else,
+		})
+	}
+	return w
 }