Merge pull request #54 from spotify/20200131-expose-lexer

Expose redactor

Author: ecamacho

Sources/XCLogParser/lexer/LexRedactor.swift

@@ -0,0 +1,50 @@
+// Copyright (c) 2020 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+
+public class LexRedactor: LogRedactor {
+    private static let redactedTemplate = "/Users/<redacted>/"
+    private lazy var userDirRegex: NSRegularExpression? = {
+        do {
+            return try NSRegularExpression(pattern: "\\/Users\\/(\\w*)\\/")
+        } catch {
+            return nil
+        }
+    }()
+    public var userDirToRedact: String?
+
+    public func redactUserDir(string: String) -> String {
+        guard let regex = userDirRegex else {
+            return string
+        }
+        if let userDirToRedact = userDirToRedact {
+            return string.replacingOccurrences(of: userDirToRedact, with: Self.redactedTemplate)
+        } else {
+            guard let firstMatch = regex.firstMatch(in: string,
+                                                    options: [],
+                                                    range: NSRange(location: 0, length: string.count)) else {
+                return string
+            }
+            let userDir = string.substring(firstMatch.range)
+            userDirToRedact = userDir
+            return string.replacingOccurrences(of: userDir, with: Self.redactedTemplate)
+        }
+    }
+}

Sources/XCLogParser/lexer/Lexer.swift

@@ -22,24 +22,24 @@ import Foundation
 public final class Lexer {
 
     static let SLFHeader = "SLF"
-    static let redactedTemplate = "/Users/<redacted>/"
 
     let typeDelimiters: CharacterSet
     let filePath: String
     var classNames = [String]()
-    var userDirToRedact: String?
-
-    lazy var userDirRegex: NSRegularExpression? = {
-        do {
-            return try NSRegularExpression(pattern: "\\/Users\\/(\\w*)\\/")
-        } catch {
-            return nil
+    var userDirToRedact: String? {
+        set {
+            redactor.userDirToRedact = newValue
+        }
+        get {
+            redactor.userDirToRedact
         }
-    }()
+    }
+    private var redactor: LogRedactor
 
     public init(filePath: String) {
         self.filePath = filePath
         self.typeDelimiters = CharacterSet(charactersIn: TokenType.all())
+        self.redactor = LexRedactor()
     }
 
     /// Tokenizes an xcactivitylog serialized in the `SLF` format
@@ -188,7 +188,7 @@ public final class Lexer {
         #endif
         scanner.scanLocation += value
         if redacted {
-            return redactUserDir(string: String(scanner.string[start..<end]))
+            return redactor.redactUserDir(string: String(scanner.string[start..<end]))
         }
         return String(scanner.string[start..<end])
     }
@@ -200,24 +200,6 @@ public final class Lexer {
         let result =  Double(bitPattern: beValue.byteSwapped)
         return result
     }
-
-    private func redactUserDir(string: String) -> String {
-        guard let regex = userDirRegex else {
-            return string
-        }
-        if let userDirToRedact = userDirToRedact {
-            return string.replacingOccurrences(of: userDirToRedact, with: Self.redactedTemplate)
-        } else {
-            guard let firstMatch = regex.firstMatch(in: string,
-                                                    options: [],
-                                                    range: NSRange(location: 0, length: string.count)) else {
-                return string
-            }
-            let userDir = string.substring(firstMatch.range)
-            userDirToRedact = userDir
-            return string.replacingOccurrences(of: userDir, with: Self.redactedTemplate)
-        }
-    }
 }
 
 extension Scanner {

Sources/XCLogParser/lexer/LogRedactor.swift

@@ -0,0 +1,29 @@
+// Copyright (c) 2020 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+public protocol LogRedactor {
+    /// Predefined (or inferrred during redation process) user home path.
+    /// Introduced for better performance.
+    var userDirToRedact: String? {get set}
+
+    /// Redacts a string by replacing sensitive username path with a template
+    /// - parameter string: The string to redact
+    /// - returns: Redacted text with
+    func redactUserDir(string: String) -> String
+}

Tests/XCLogParserTests/LexRedactorTests.swift

@@ -0,0 +1,62 @@
+// Copyright (c) 2020 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+import XCTest
+@testable import XCLogParser
+
+class LexRedactorTests: XCTestCase {
+    let redactor = LexRedactor()
+
+    func testRedacting() {
+
+        let redactedText = redactor.redactUserDir(string: "Some /Users/private/path")
+
+        XCTAssertEqual(redactedText, "Some /Users/<redacted>/path")
+    }
+
+    func testMultiplePathsRedacting() {
+
+        let redactedText = redactor.redactUserDir(string: "Some /Users/private/path and other /Users/private/path2")
+
+        XCTAssertEqual(redactedText, "Some /Users/<redacted>/path and other /Users/<redacted>/path2")
+    }
+
+    func testRedactingFillsUserDir() {
+        _ = redactor.redactUserDir(string: "Some /Users/private/path")
+
+        XCTAssertEqual(redactor.userDirToRedact, "/Users/private/")
+    }
+
+    func testPredefinedUserDirIsRedacted() {
+        redactor.userDirToRedact = "/Users/private/"
+
+        let redactedText = redactor.redactUserDir(string: "Some /Users/private/path")
+
+        XCTAssertEqual(redactedText, "Some /Users/<redacted>/path")
+    }
+
+    func testNotInPredefinedUserDirIsNotRedacted() {
+        redactor.userDirToRedact = "/Users/priv/"
+
+        let redactedText = redactor.redactUserDir(string: "Some /Users/private/path")
+
+        XCTAssertEqual(redactedText, "Some /Users/private/path")
+    }
+}