Cache folded syntax tree (#4744)

Source/SwiftLintFramework/Extensions/SourceFileSyntax+SwiftSyntax.swift

@@ -1,10 +0,0 @@
-import SwiftOperators
-import SwiftSyntax
-
-extension SourceFileSyntax {
-    func folded() -> SourceFileSyntax? {
-        OperatorTable.standardOperators
-            .foldAll(self) { _ in }
-            .as(SourceFileSyntax.self)
-    }
-}

Source/SwiftLintFramework/Extensions/SwiftLintFile+Cache.swift

@@ -4,6 +4,7 @@ import Darwin
 import Foundation
 import IDEUtils
 import SourceKittenFramework
+import SwiftOperators
 import SwiftParser
 import SwiftParserDiagnostics
 import SwiftSyntax
@@ -25,6 +26,11 @@ private let structureDictionaryCache = Cache { file in
 private let syntaxTreeCache = Cache { file -> SourceFileSyntax in
     return Parser.parse(source: file.contents)
 }
+private let foldedSyntaxTreeCache = Cache { file -> SourceFileSyntax? in
+    return OperatorTable.standardOperators
+        .foldAll(file.syntaxTree) { _ in }
+        .as(SourceFileSyntax.self)
+}
 private let locationConverterCache = Cache { file -> SourceLocationConverter in
     return SourceLocationConverter(file: file.path ?? "<nopath>", tree: file.syntaxTree)
 }
@@ -155,6 +161,8 @@ extension SwiftLintFile {
 
     internal var syntaxTree: SourceFileSyntax { syntaxTreeCache.get(self) }
 
+    internal var foldedSyntaxTree: SourceFileSyntax? { foldedSyntaxTreeCache.get(self) }
+
     internal var locationConverter: SourceLocationConverter { locationConverterCache.get(self) }
 
     internal var commands: [Command] { commandsCache.get(self) }
@@ -192,6 +200,7 @@ extension SwiftLintFile {
         syntaxTokensByLinesCache.invalidate(self)
         syntaxKindsByLinesCache.invalidate(self)
         syntaxTreeCache.invalidate(self)
+        foldedSyntaxTreeCache.invalidate(self)
         locationConverterCache.invalidate(self)
         commandsCache.invalidate(self)
         linesWithTokensCache.invalidate(self)
@@ -207,6 +216,7 @@ extension SwiftLintFile {
         syntaxTokensByLinesCache.clear()
         syntaxKindsByLinesCache.clear()
         syntaxTreeCache.clear()
+        foldedSyntaxTreeCache.clear()
         locationConverterCache.clear()
         commandsCache.clear()
         linesWithTokensCache.clear()

Source/SwiftLintFramework/Protocols/SwiftSyntaxRule.swift

@@ -24,7 +24,7 @@ public protocol SwiftSyntaxRule: SourceKitFreeRule {
     /// - parameter syntaxTree: The syntax tree to run pre-processing on
     ///
     /// - returns: The tree that will be used to check for violations. If `nil`, this rule will return no violations.
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax?
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax?
 }
 
 public extension SwiftSyntaxRule where Self: ConfigurationProviderRule,
@@ -53,7 +53,7 @@ public extension SwiftSyntaxRule {
     }
 
     func validate(file: SwiftLintFile) -> [StyleViolation] {
-        guard let syntaxTree = preprocess(syntaxTree: file.syntaxTree) else {
+        guard let syntaxTree = preprocess(file: file) else {
             return []
         }
 
@@ -79,8 +79,8 @@ public extension SwiftSyntaxRule {
         )
     }
 
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax? {
-        syntaxTree
+        file.syntaxTree
     }
 }
 

Source/SwiftLintFramework/Rules/Idiomatic/LegacyMultipleRule.swift

@@ -39,8 +39,8 @@ struct LegacyMultipleRule: OptInRule, ConfigurationProviderRule, SwiftSyntaxRule
         ]
     )
 
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax? {
-        syntaxTree.folded()
+        file.foldedSyntaxTree
     }
 
     func makeVisitor(file: SwiftLintFile) -> ViolationsSyntaxVisitor {

Source/SwiftLintFramework/Rules/Lint/IdenticalOperandsRule.swift

@@ -72,8 +72,8 @@ struct IdenticalOperandsRule: ConfigurationProviderRule, SwiftSyntaxRule, OptInR
         ]
     )
 
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax? {
-        syntaxTree.folded()
+        file.foldedSyntaxTree
     }
 
     func makeVisitor(file: SwiftLintFile) -> ViolationsSyntaxVisitor {

Source/SwiftLintFramework/Rules/Performance/ContainsOverFirstNotNilRule.swift

@@ -34,8 +34,8 @@ struct ContainsOverFirstNotNilRule: SwiftSyntaxRule, OptInRule, ConfigurationPro
         Visitor(viewMode: .sourceAccurate)
     }
 
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax? {
-        syntaxTree.folded()
+        file.foldedSyntaxTree
     }
 }
 

Source/SwiftLintFramework/Rules/Performance/ContainsOverRangeNilComparisonRule.swift

@@ -23,8 +23,8 @@ struct ContainsOverRangeNilComparisonRule: SwiftSyntaxRule, OptInRule, Configura
         }
     )
 
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax? {
-        syntaxTree.folded()
+        file.foldedSyntaxTree
     }
 
     func makeVisitor(file: SwiftLintFile) -> ViolationsSyntaxVisitor {

Source/SwiftLintFramework/Rules/Performance/EmptyCountRule.swift

@@ -35,8 +35,8 @@ struct EmptyCountRule: ConfigurationProviderRule, OptInRule, SwiftSyntaxRule {
         ]
     )
 
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax? {
-        syntaxTree.folded()
+        file.foldedSyntaxTree
     }
 
     func makeVisitor(file: SwiftLintFile) -> ViolationsSyntaxVisitor {

Source/SwiftLintFramework/Rules/Style/ShorthandOperatorRule.swift

@@ -47,8 +47,8 @@ struct ShorthandOperatorRule: ConfigurationProviderRule, SwiftSyntaxRule {
 
     fileprivate static let allOperators = ["-", "/", "+", "*"]
 
-    func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
+    func preprocess(file: SwiftLintFile) -> SourceFileSyntax? {
-        syntaxTree.folded()
+        file.foldedSyntaxTree
     }
 
     func makeVisitor(file: SwiftLintFile) -> ViolationsSyntaxVisitor {