From bbcdf2e06e0c69325cd02e7984f805e0087e4584 Mon Sep 17 00:00:00 2001
From: Marcelo Fabri <me@marcelofabri.com>
Date: Tue, 12 Oct 2021 01:02:20 -0700
Subject: [PATCH] Handle `get async` and `get throws` in `implicit_getter`

Fixes #3684
---
 CHANGELOG.md                                  |  4 ++
 .../Models/SwiftVersion.swift                 |  2 +
 .../Rules/Style/ImplicitGetterRule.swift      | 18 ++++++++-
 .../Style/ImplicitGetterRuleExamples.swift    | 39 +++++++++++++++----
 4 files changed, 54 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f08b598557..960fddb7f3e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,10 @@
   [Artem Garmash](https://github.com/agarmash)
   [#3651](https://github.com/realm/SwiftLint/issues/3651)
 
+* Handle `get async` and `get throws` in the `implicit_getter` rule.  
+  [Marcelo Fabri](https://github.com/marcelofabri)
+  [#3684](https://github.com/realm/SwiftLint/issues/3684)
+
 #### Bug Fixes
 
 * Fixes a bug with the `missing_docs` rule where `excludes_inherited_types` would not be set.
diff --git a/Source/SwiftLintFramework/Models/SwiftVersion.swift b/Source/SwiftLintFramework/Models/SwiftVersion.swift
index cce7b0a027e..f4cadf31af8 100644
--- a/Source/SwiftLintFramework/Models/SwiftVersion.swift
+++ b/Source/SwiftLintFramework/Models/SwiftVersion.swift
@@ -35,6 +35,8 @@ public extension SwiftVersion {
     static let fiveDotThree = SwiftVersion(rawValue: "5.3.0")
     /// Swift 5.4.x - https://swift.org/download/#swift-54
     static let fiveDotFour = SwiftVersion(rawValue: "5.4.0")
+    /// Swift 5.5.x - https://swift.org/download/#swift-55
+    static let fiveDotFive = SwiftVersion(rawValue: "5.5.0")
 
     /// The current detected Swift compiler version, based on the currently accessible SourceKit version.
     ///
diff --git a/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRule.swift b/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRule.swift
index 16097fb971a..11f0815de28 100644
--- a/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRule.swift
+++ b/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRule.swift
@@ -31,7 +31,7 @@ public struct ImplicitGetterRule: ConfigurationProviderRule, AutomaticTestableRu
                     return nil
                 }
             } else {
-                guard let range = dict.byteRange.map(file.stringView.byteRangeToNSRange) else {
+                guard let range = dict.byteRange.flatMap(file.stringView.byteRangeToNSRange) else {
                     return nil
                 }
 
@@ -51,6 +51,22 @@ public struct ImplicitGetterRule: ConfigurationProviderRule, AutomaticTestableRu
                 }
             }
 
+            // If there's another keyword after `get`, it's allowed (e.g. `get async`)
+            if SwiftVersion.current >= .fiveDotFive {
+                guard let byteRange = dict.byteRange else {
+                    return nil
+                }
+
+                let nextToken = file.syntaxMap.tokens(inByteRange: byteRange)
+                    .first { $0.offset > token.offset }
+
+                let allowedKeywords: Set = ["throws", "async"]
+                if let nextToken = nextToken,
+                   allowedKeywords.contains(file.contents(for: nextToken) ?? "") {
+                    return nil
+                }
+            }
+
             let kind = dict.declarationKind
             return (token.offset, kind)
         }
diff --git a/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRuleExamples.swift b/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRuleExamples.swift
index 7bfd31e4a86..a41f3cd5bf4 100644
--- a/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRuleExamples.swift
+++ b/Source/SwiftLintFramework/Rules/Style/ImplicitGetterRuleExamples.swift
@@ -138,14 +138,7 @@ struct ImplicitGetterRuleExamples {
                     }
                 }
             }
-            """)
-        ]
-
-        guard SwiftVersion.current >= .fourDotOne else {
-            return commonExamples
-        }
-
-        return commonExamples + [
+            """),
             Example("""
             class Foo {
                 subscript(i: Int) -> Int {
@@ -172,6 +165,36 @@ struct ImplicitGetterRuleExamples {
             }
             """)
         ]
+
+        guard SwiftVersion.current >= .fiveDotFive else {
+            return commonExamples
+        }
+
+        return commonExamples + [
+            Example("""
+            class DatabaseEntity {
+                var isSynced: Bool {
+                    get async {
+                        await database.isEntitySynced(self)
+                    }
+                }
+            }
+            """),
+            Example("""
+            struct Test {
+                subscript(value: Int) -> Int {
+                    get throws {
+                        if value == 0 {
+                            throw NSError()
+                        } else {
+                            return value
+                        }
+                    }
+                }
+            }
+            """)
+        ]
+
     }
 
     static var triggeringExamples: [Example] {