[OPEN DEV] Add Swiftlint to BraintreeCore

.github/workflows/swiftlint.yml

@@ -0,0 +1,18 @@
+name: Lint
+on: [pull_request]
+concurrency:
+  group: lint-${{ github.event.number }}
+  cancel-in-progress: true
+jobs:
+  swiftlint:
+    name: SwiftLint
+    runs-on: macOS-14-xlarge
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v3
+      - name: Use Xcode 15.0.1
+        run: sudo xcode-select -switch /Applications/Xcode_15.0.1.app
+      - name: Install SwiftLint
+        run: brew install swiftlint
+      - name: Run SwiftLint
+        run: swiftlint --strict

.swiftlint.yml

@@ -0,0 +1,106 @@
+# Reference: https://github.com/realm/SwiftLint
+# Required Swiftlint Version
+# swiftlint_version: 0.39.2
+
+# Paths to include in lint
+included:
+  - Sources/BraintreeCore
+
+excluded:
+  - Sources/BraintreeCore/BTAPIPinnedCertificates.swift
+
+disabled_rules:
+  - todo
+  - type_name # tests will have the format <SUT>_Tests
+  - xctfail_message
+  - blanket_disable_command
+  - non_optional_string_data_conversion
+  - attributes
+  - multiline_function_chains
+
+opt_in_rules:
+  - array_init
+  - closure_end_indentation
+  - closure_spacing
+  - collection_alignment
+  - colon # promote to error
+  - convenience_type
+  - discouraged_object_literal
+  - empty_collection_literal
+  - empty_count
+  - empty_string
+  - enum_case_associated_values_count
+  - fatal_error_message
+  - first_where
+  - force_unwrapping
+  - implicitly_unwrapped_optional
+  - indentation_width
+  - last_where
+  - legacy_random
+  - literal_expression_end_indentation
+  - multiline_arguments
+  - multiline_function_chains
+  - multiline_literal_brackets
+  - multiline_parameters
+  - multiline_parameters_brackets
+  - operator_usage_whitespace
+  - overridden_super_call
+  - pattern_matching_keywords
+  - prefer_self_type_over_type_of_self
+  - redundant_nil_coalescing
+  - redundant_type_annotation
+  - strict_fileprivate
+  - toggle_bool
+  - trailing_closure
+  - unneeded_parentheses_in_closure_argument
+  - vertical_whitespace_closing_braces
+  - yoda_condition
+
+custom_rules:
+  array_constructor:
+    name: "Array/Dictionary initializer"
+    regex: '[let,var] .+ = (\[.+\]\(\))'
+    capture_group: 1
+    message: "Use explicit type annotation when initializing empty arrays and dictionaries"
+    severity: warning
+  space_after_main_type:
+    name: "No space after main type"
+    regex: '(class|struct|extension)((?-s)\s.*\{$\n)(?!^\s*$)' 
+    message: "Empty line required after main declarations"
+    severity: warning
+
+force_cast: warning
+force_try: warning
+function_body_length:
+    warning: 60
+
+legacy_hashing: error
+
+identifier_name:
+  excluded:
+    - i
+    - id
+    - x
+    - y
+    - z
+
+indentation_width:
+  indentation_width: 4
+
+line_length:
+  warning: 140
+  ignores_urls: true
+  ignores_comments: true
+
+multiline_arguments:
+  first_argument_location: next_line
+  only_enforce_after_first_closure_on_first_line: true
+
+private_over_fileprivate:
+  validate_extensions: true
+
+trailing_whitespace:
+  ignores_empty_lines: true
+
+vertical_whitespace:
+  max_empty_lines: 2 

Braintree.xcodeproj/project.pbxproj

@@ -2237,6 +2237,7 @@
 				570B9385285397520041BAFE /* Frameworks */,
 				570B9386285397520041BAFE /* Headers */,
 				570B93A8285397520041BAFE /* Resources */,
+				BE676C532C417B8F000A6579 /* Swiftlint */,
 			);
 			buildRules = (
 			);
@@ -3154,6 +3155,26 @@
 			shellScript = "diff \"${PODS_PODFILE_DIR_PATH}/Podfile.lock\" \"${PODS_ROOT}/Manifest.lock\" > /dev/null\nif [ $? != 0 ] ; then\n    # print error to STDERR\n    echo \"error: The sandbox is not in sync with the Podfile.lock. Run 'pod install' or update your CocoaPods installation.\" >&2\n    exit 1\nfi\n# This output is used by Xcode 'outputs' to avoid re-running this script phase.\necho \"SUCCESS\" > \"${SCRIPT_OUTPUT_FILE_0}\"\n";
 			showEnvVarsInLog = 0;
 		};
+		BE676C532C417B8F000A6579 /* Swiftlint */ = {
+			isa = PBXShellScriptBuildPhase;
+			alwaysOutOfDate = 1;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			inputFileListPaths = (
+			);
+			inputPaths = (
+			);
+			name = Swiftlint;
+			outputFileListPaths = (
+			);
+			outputPaths = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+			shellPath = /bin/sh;
+			shellScript = "#!/bin/sh\n\nif test -d \"/opt/homebrew/bin/\"; then\n  PATH=\"/opt/homebrew/bin/:${PATH}\"\nfi\n\nexport PATH\n\nif which swiftlint >/dev/null; then\n  swiftlint\nelse\n  echo \"warning: SwiftLint not installed, download from https://github.com/realm/SwiftLint\"\nfi\n";
+			showEnvVarsInLog = 0;
+		};
 		CDAB67F3BC5BE564FCFFD6BC /* [CP] Embed Pods Frameworks */ = {
 			isa = PBXShellScriptBuildPhase;
 			buildActionMask = 2147483647;

DEVELOPMENT.md

@@ -6,6 +6,16 @@ This document outlines development practices that we follow while developing thi
 
 The included demo app utilizes a [sandbox sample merchant server](https://braintree-sample-merchant.herokuapp.com) hosted on Heroku.
 
+## SwiftLint
+
+Ensure that you have [SwiftLint](https://github.com/realm/SwiftLint) installed as we utilize it within our project.
+
+To install via [Homebrew](https://brew.sh/) run:
+```
+brew install swiftlint
+```
+Our Xcode workspace has a `Run Phase` which integrates in `SwiftLint` so the only prerequisite is installing via `Homebrew`.
+
 ## Tests
 
 Each module has a corresponding unit test target. These can be run individually, or all at once via the `UnitTests` scheme.

README.md

@@ -84,11 +84,12 @@ Versions 4.9.6 and below use outdated SSL certificates and are unsupported.
 
 ## Demo
 
+1. Our Xcode project uses SwiftLint. To ensure you have it installed see [DEVELOPMENT.md](https://github.com/braintree/braintree_ios/blob/main/DEVELOPMENT.md#swiftlint)
 1. Run `pod install`
     * There is a known M1 mac issue with CocoaPods. See [this solution](https://github.com/CocoaPods/CocoaPods/issues/10220#issuecomment-730963835) to resolve `ffi` dependency issues.
-2. Resolve the Swift Package Manager packages if needed: `File` > `Packages` > `Resolve Package Versions` or by running `swift package resolve` in Terminal
-3. Open `Braintree.xcworkspace` in Xcode
-4. Select the `Demo` scheme, and then run
+1. Resolve the Swift Package Manager packages if needed: `File` > `Packages` > `Resolve Package Versions` or by running `swift package resolve` in Terminal
+1. Open `Braintree.xcworkspace` in Xcode
+1. Select the `Demo` scheme, and then run
 
 Xcode 15.0+ is required to run the demo app.
 

Sources/BraintreeCore/Analytics/BTAnalyticsService.swift

@@ -4,8 +4,10 @@ class BTAnalyticsService: Equatable {
 
     // MARK: - Internal Properties
 
+    // swiftlint:disable force_unwrapping
     /// The FPTI URL to post all analytic events.
     static let url = URL(string: "https://api.paypal.com")!
+    // swiftlint:enable force_unwrapping
 
     /// The HTTP client for communication with the analytics service endpoint. Exposed for testing.
     var http: BTHTTP?
@@ -131,7 +133,11 @@ class BTAnalyticsService: Equatable {
         if await !BTAnalyticsService.events.isEmpty {
             do {
                 let configuration = try await apiClient.fetchConfiguration()
-                let postParameters = await createAnalyticsEvent(config: configuration, sessionID: apiClient.metadata.sessionID, events: Self.events.allValues)
+                let postParameters = await createAnalyticsEvent(
+                    config: configuration,
+                    sessionID: apiClient.metadata.sessionID,
+                    events: Self.events.allValues
+                )
                 http?.post("v1/tracking/batch/events", parameters: postParameters) { _, _, _ in }
                 await Self.events.removeAll()
             } catch {

Sources/BraintreeCore/Analytics/FPTIBatchData.swift

@@ -1,15 +1,18 @@
 import UIKit
 
+// swiftlint:disable nesting
 /// The POST body for a batch upload of FPTI events
 struct FPTIBatchData: Codable {
 
     let events: [EventsContainer] // Single-element "events" array required by FPTI formatting
 
     init(metadata: Metadata, events fptiEvents: [Event]?) {
-        self.events = [EventsContainer(
-            metadata: metadata,
-            fptiEvents: fptiEvents ?? []
-        )]
+        self.events = [
+            EventsContainer(
+                metadata: metadata,
+                fptiEvents: fptiEvents ?? []
+            )
+        ]
     }
 
     struct EventsContainer: Codable {

Sources/BraintreeCore/Authorization/BTClientToken.swift

@@ -3,7 +3,7 @@ import Foundation
 /// An authorization string used to initialize the Braintree SDK
 @_documentation(visibility: private)
 @objcMembers public class BTClientToken: NSObject, NSCoding, NSCopying, ClientAuthorization {
-    
+
     // NEXT_MAJOR_VERSION (v7): properties exposed for Objective-C interoperability + Drop-in access.
     // Once the entire SDK is in Swift, determine if we want public properties to be internal and
     // what we can make internal without breaking the Drop-in.
@@ -38,8 +38,7 @@ import Foundation
         // Client token must be decoded first because the other values are retrieved from it
         self.json = try Self.decodeClientToken(clientToken)
 
-        guard let authorizationFingerprint = json["authorizationFingerprint"].asString(),
-              !authorizationFingerprint.isEmpty else {
+        guard let authorizationFingerprint = json["authorizationFingerprint"].asString(), !authorizationFingerprint.isEmpty else {
             throw BTClientTokenError.invalidAuthorizationFingerprint
         }
 
@@ -113,8 +112,7 @@ import Foundation
     // MARK: - NSObject override
 
     public override func isEqual(_ object: Any?) -> Bool {
-        guard object is BTClientToken,
-              let otherToken = object as? BTClientToken else {
+        guard object is BTClientToken, let otherToken = object as? BTClientToken else {
             return false
         }
 

Sources/BraintreeCore/Authorization/BTClientTokenError.swift

@@ -37,6 +37,7 @@ public enum BTClientTokenError: Error, CustomNSError, LocalizedError, Equatable
         }
     }
 
+    // swiftlint:disable line_length
     public var errorDescription: String? {
         switch self {
         case .invalidAuthorizationFingerprint:
@@ -51,4 +52,5 @@ public enum BTClientTokenError: Error, CustomNSError, LocalizedError, Equatable
             return "Failed to decode client token. \(description)"
         }
     }
+    // swiftlint:enable line_length
 }

Sources/BraintreeCore/Authorization/TokenizationKey.swift

@@ -27,10 +27,10 @@ class TokenizationKey: ClientAuthorization {
         guard tokenizationKey.range(of: pattern, options: .regularExpression) != nil else { return nil }
 
         let tokenizationKeyParts = tokenizationKey.split(separator: "_", maxSplits: 3)
-        let environment: String = String(tokenizationKeyParts[0])
-        let merchantID: String = String(tokenizationKeyParts[2])
+        let environment = String(tokenizationKeyParts[0])
+        let merchantID = String(tokenizationKeyParts[2])
 
-        var components: URLComponents = URLComponents()
+        var components = URLComponents()
         components.scheme = environment == "development" ? "http" : "https"
 
         guard let host = host(for: environment) else { return nil }

Sources/BraintreeCore/Authorization/TokenizationKeyError.swift

@@ -21,4 +21,3 @@ public enum TokenizationKeyError: Int, Error, CustomNSError, LocalizedError, Equ
         }
     }
 }
-

Sources/BraintreeCore/BTAPIClient.swift

@@ -1,5 +1,6 @@
 import Foundation
 
+// swiftlint:disable type_body_length file_length
 /// This class acts as the entry point for accessing the Braintree APIs via common HTTP methods performed on API endpoints.
 /// - Note: It also manages authentication via tokenization key and provides access to a merchant's gateway configuration.
 @objcMembers public class BTAPIClient: NSObject, BTHTTPNetworkTiming {
@@ -46,7 +47,7 @@ import Foundation
         switch authorizationType {
         case .tokenizationKey:
             do {
-                self.authorization =  try TokenizationKey(authorization)
+                self.authorization = try TokenizationKey(authorization)
             } catch {
                 return nil
             }
@@ -68,7 +69,7 @@ import Foundation
         http?.networkTimingDelegate = self
 
         // Kickoff the background request to fetch the config
-        fetchOrReturnRemoteConfiguration { configuration, error in
+        fetchOrReturnRemoteConfiguration { _, _ in
             // No-op
         }
     }
@@ -148,7 +149,7 @@ import Foundation
             "session_id": metadata.sessionID
         ]
 
-        get("v1/payment_methods", parameters: parameters) { body, response, error in
+        get("v1/payment_methods", parameters: parameters) { body, _, error in
             if let error {
                 completion(nil, error)
                 return
@@ -158,7 +159,10 @@ import Foundation
 
             body?["paymentMethods"].asArray()?.forEach { paymentInfo in
                 let type: String? = paymentInfo["type"].asString()
-                let paymentMethodNonce: BTPaymentMethodNonce? = BTPaymentMethodNonceParser.shared.parseJSON(paymentInfo, withParsingBlockForType: type)
+                let paymentMethodNonce: BTPaymentMethodNonce? = BTPaymentMethodNonceParser.shared.parseJSON(
+                    paymentInfo,
+                    withParsingBlockForType: type
+                )
 
                 if let paymentMethodNonce {
                     paymentMethodNonces.append(paymentMethodNonce)
@@ -269,7 +273,13 @@ import Foundation
             }
 
             let postParameters = BTAPIRequest(requestBody: parameters, metadata: metadata, httpType: httpType)
-            http(for: httpType)?.post(path, configuration: configuration, parameters: postParameters, headers: headers, completion: completion)
+            http(for: httpType)?.post(
+                path,
+                configuration: configuration,
+                parameters: postParameters,
+                headers: headers,
+                completion: completion
+            )
         }
     }
 
@@ -339,7 +349,11 @@ import Foundation
         let pattern: String = "([a-zA-Z0-9]+)_[a-zA-Z0-9]+_([a-zA-Z0-9_]+)"
         guard let regularExpression = try? NSRegularExpression(pattern: pattern) else { return nil }
 
-        let tokenizationKeyMatch: NSTextCheckingResult? = regularExpression.firstMatch(in: authorization, options: [], range: NSRange(location: 0, length: authorization.count))
+        let tokenizationKeyMatch: NSTextCheckingResult? = regularExpression.firstMatch(
+            in: authorization,
+            options: [],
+            range: NSRange(location: 0, length: authorization.count)
+        )
 
         return tokenizationKeyMatch != nil ? .tokenizationKey : .clientToken
     }