Fix redundant public accessibility analysis for types used in closure signatures. Closes #522 (#542)

Author: ileitch

CHANGELOG.md

@@ -14,6 +14,7 @@
 - Fix unused parameter analysis for shorthand if-let syntax.
 - Workaround Swift shorthand if-let syntax bug (https://github.com/apple/swift/issues/61509). Global properties are not handled by this workaround.
 - Fix retaining inferred associated types.
+- Fix redundant public accessibility analysis for types used in closure signatures.
 
 ## 2.10.0 (2022-10-10)
 

Sources/PeripheryKit/Syntax/DeclarationVisitor.swift

@@ -171,11 +171,15 @@ final class DeclarationVisitor: PeripherySyntaxVisitor {
     func visitPost(_ node: VariableDeclSyntax) {
         for binding in node.bindings {
             if binding.pattern.is(IdentifierPatternSyntax.self) {
+                let closureSignature = binding.initializer?.value.as(ClosureExprSyntax.self)?.signature
+                let closureParameters = closureSignature?.input?.as(ParameterClauseSyntax.self)
                 parse(
                     modifiers: node.modifiers,
                     attributes: node.attributes,
                     trivia: node.leadingTrivia,
                     variableType: binding.typeAnnotation?.type,
+                    parameterClause: closureParameters,
+                    returnClause: closureSignature?.output,
                     at: binding.positionAfterSkippingLeadingTrivia
                 )
             } else if let tuplePatternSyntax = binding.pattern.as(TuplePatternSyntax.self) {

Tests/AccessibilityTests/AccessibilityProject/Sources/MainTarget/main.swift

@@ -54,3 +54,6 @@ _ = InternalClassAdoptingPublicProtocolRetainer()
 let _: PublicProtocolRefiningPublicProtocol? = nil
 _ = InternalProtocolRefiningPublicProtocolRetainer()
 
+// Closure
+let _ = PublicTypeUsedInPublicClosureRetainer().closure
+

Tests/AccessibilityTests/AccessibilityProject/Sources/TargetA/PublicTypeUsedInPublicClosure.swift

@@ -0,0 +1,11 @@
+import Foundation
+
+public class PublicTypeUsedInPublicClosureReturnType {}
+public class PublicTypeUsedInPublicClosureInputType {}
+
+public class PublicTypeUsedInPublicClosureRetainer {
+    public var closure = { (a: PublicTypeUsedInPublicClosureInputType) -> PublicTypeUsedInPublicClosureReturnType in
+        PublicTypeUsedInPublicClosureReturnType()
+    }
+    public init() {}
+}

Tests/AccessibilityTests/RedundantPublicAccessibilityTest.swift

@@ -148,4 +148,9 @@ class RedundantPublicAccessibilityTest: SourceGraphTestCase {
         assertNotRedundantPublicAccessibility(.typealias("PublicTypealiasWithClosureType"))
         assertNotRedundantPublicAccessibility(.struct("PublicTypealiasStruct"))
     }
+
+    func testPublicTypeUsedInPublicClosure() {
+        assertNotRedundantPublicAccessibility(.class("PublicTypeUsedInPublicClosureReturnType"))
+        assertNotRedundantPublicAccessibility(.class("PublicTypeUsedInPublicClosureInputType"))
+    }
 }