Add new multiline_call_arguments rule (#6223)

Co-authored-by: Danny Mösch <danny.moesch@icloud.com>

.swiftlint.yml

@@ -32,6 +32,7 @@ disabled_rules:
   - missing_docs
   - multiline_arguments
   - multiline_arguments_brackets
+  - multiline_call_arguments
   - multiline_function_chains
   - multiline_parameters_brackets
   - no_extension_access_modifier

CHANGELOG.md

@@ -31,6 +31,10 @@
 * Add new `unneeded_escaping` rule that detects closure parameters marked with
   `@escaping` that are never stored or captured escapingly.  
   [SimplyDanny](https://github.com/SimplyDanny)
+  
+* Add `multiline_call_arguments` opt-in rule to enforce consistent multiline
+  formatting for function and method call arguments.  
+  [GandaLF2006](https://github.com/GandaLF2006)
 
 ### Bug Fixes
 

Source/SwiftLintBuiltInRules/Models/BuiltInRules.swift

@@ -118,6 +118,7 @@ public let builtInRules: [any Rule.Type] = [
     ModifierOrderRule.self,
     MultilineArgumentsBracketsRule.self,
     MultilineArgumentsRule.self,
+    MultilineCallArgumentsRule.self,
     MultilineFunctionChainsRule.self,
     MultilineLiteralBracketsRule.self,
     MultilineParametersBracketsRule.self,

Source/SwiftLintBuiltInRules/Rules/Lint/MultilineCallArgumentsRule.swift

@@ -0,0 +1,109 @@
+import SwiftLintCore
+import SwiftSyntax
+
+@SwiftSyntaxRule(optIn: true)
+struct MultilineCallArgumentsRule: Rule {
+    var configuration = MultilineCallArgumentsConfiguration()
+
+    static let description = RuleDescription(
+        identifier: "multiline_call_arguments",
+        name: "Multiline Call Arguments",
+        description: "Call should have each parameter on a separate line",
+        kind: .style,
+        nonTriggeringExamples: [
+            Example("""
+                foo(
+                param1: "param1",
+                    param2: false,
+                    param3: []
+                )
+                """,
+                configuration: ["max_number_of_single_line_parameters": 2]),
+            Example("""
+                foo(param1: 1,
+                    param2: false,
+                    param3: [])
+                """,
+                configuration: ["max_number_of_single_line_parameters": 1]),
+            Example(
+                "foo(param1: 1, param2: false)",
+                configuration: ["max_number_of_single_line_parameters": 2]),
+            Example(
+                "Enum.foo(param1: 1, param2: false)",
+                configuration: ["max_number_of_single_line_parameters": 2]),
+            Example("foo(param1: 1)", configuration: ["allows_single_line": false]),
+            Example("Enum.foo(param1: 1)", configuration: ["allows_single_line": false]),
+            Example(
+                "Enum.foo(param1: 1, param2: 2, param3: 3)",
+                configuration: ["allows_single_line": true]),
+            Example("""
+                foo(
+                    param1: 1,
+                    param2: 2,
+                    param3: 3
+                )
+                """,
+                configuration: ["allows_single_line": false]),
+        ],
+        triggeringExamples: [
+            Example(
+                "↓foo(param1: 1, param2: false, param3: [])",
+                configuration: ["max_number_of_single_line_parameters": 2]),
+            Example(
+                "↓Enum.foo(param1: 1, param2: false, param3: [])",
+                configuration: ["max_number_of_single_line_parameters": 2]),
+            Example("""
+                ↓foo(param1: 1, param2: false,
+                        param3: [])
+                """,
+                configuration: ["max_number_of_single_line_parameters": 3]),
+            Example("""
+                ↓Enum.foo(param1: 1, param2: false,
+                        param3: [])
+                """,
+                configuration: ["max_number_of_single_line_parameters": 3]),
+            Example("↓foo(param1: 1, param2: false)", configuration: ["allows_single_line": false]),
+            Example("↓Enum.foo(param1: 1, param2: false)", configuration: ["allows_single_line": false]),
+        ]
+    )
+}
+
+private extension MultilineCallArgumentsRule {
+    final class Visitor: ViolationsSyntaxVisitor<ConfigurationType> {
+        override func visitPost(_ node: FunctionCallExprSyntax) {
+            if containsViolation(parameterPositions: node.arguments.map(\.positionAfterSkippingLeadingTrivia)) {
+                violations.append(node.calledExpression.positionAfterSkippingLeadingTrivia)
+            }
+        }
+
+        private func containsViolation(parameterPositions: [AbsolutePosition]) -> Bool {
+            var numberOfParameters = 0
+            var linesWithParameters: Set<Int> = []
+            var hasMultipleParametersOnSameLine = false
+
+            for position in parameterPositions {
+                let line = locationConverter.location(for: position).line
+
+                if !linesWithParameters.insert(line).inserted {
+                    hasMultipleParametersOnSameLine = true
+                }
+
+                numberOfParameters += 1
+            }
+
+            if linesWithParameters.count == 1 {
+                guard configuration.allowsSingleLine else {
+                    return numberOfParameters > 1
+                }
+
+                if let maxNumberOfSingleLineParameters = configuration.maxNumberOfSingleLineParameters {
+                    return numberOfParameters > maxNumberOfSingleLineParameters
+                }
+
+                return false
+            }
+
+            return hasMultipleParametersOnSameLine
+        }
+    }
+}

Source/SwiftLintBuiltInRules/Rules/RuleConfigurations/MultilineCallArgumentsConfiguration.swift

@@ -0,0 +1,35 @@
+import SwiftLintCore
+
+@AutoConfigParser
+struct MultilineCallArgumentsConfiguration: SeverityBasedRuleConfiguration {
+    typealias Parent = MultilineCallArgumentsRule
+
+    @ConfigurationElement(key: "severity")
+    private(set) var severityConfiguration = SeverityConfiguration<Parent>(.warning)
+    @ConfigurationElement(key: "allows_single_line")
+    private(set) var allowsSingleLine = true
+    @ConfigurationElement(key: "max_number_of_single_line_parameters")
+    private(set) var maxNumberOfSingleLineParameters: Int?
+
+    func validate() throws(Issue) {
+        guard let maxNumberOfSingleLineParameters else {
+            return
+        }
+        guard maxNumberOfSingleLineParameters >= 1 else {
+            throw Issue.inconsistentConfiguration(
+                ruleID: Parent.identifier,
+                message: "Option '\($maxNumberOfSingleLineParameters.key)' should be >= 1."
+            )
+        }
+
+        if maxNumberOfSingleLineParameters > 1, !allowsSingleLine {
+            throw Issue.inconsistentConfiguration(
+                ruleID: Parent.identifier,
+                message: """
+                         Option '\($maxNumberOfSingleLineParameters.key)' has no effect when \
+                         '\($allowsSingleLine.key)' is false.
+                         """
+            )
+        }
+    }
+}

Tests/GeneratedTests/GeneratedTests_05.swift

@@ -103,6 +103,12 @@ final class MultilineArgumentsRuleGeneratedTests: SwiftLintTestCase {
     }
 }
 
+final class MultilineCallArgumentsRuleGeneratedTests: SwiftLintTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(MultilineCallArgumentsRule.description)
+    }
+}
+
 final class MultilineFunctionChainsRuleGeneratedTests: SwiftLintTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(MultilineFunctionChainsRule.description)
@@ -150,9 +156,3 @@ final class NSNumberInitAsFunctionReferenceRuleGeneratedTests: SwiftLintTestCase
         verifyRule(NSNumberInitAsFunctionReferenceRule.description)
     }
 }
-
-final class NSObjectPreferIsEqualRuleGeneratedTests: SwiftLintTestCase {
-    func testWithDefaultConfiguration() {
-        verifyRule(NSObjectPreferIsEqualRule.description)
-    }
-}

Tests/GeneratedTests/GeneratedTests_06.swift

@@ -7,6 +7,12 @@
 @testable import SwiftLintCore
 import TestHelpers
 
+final class NSObjectPreferIsEqualRuleGeneratedTests: SwiftLintTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(NSObjectPreferIsEqualRule.description)
+    }
+}
+
 final class NestingRuleGeneratedTests: SwiftLintTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(NestingRule.description)
@@ -150,9 +156,3 @@ final class PreferAssetSymbolsRuleGeneratedTests: SwiftLintTestCase {
         verifyRule(PreferAssetSymbolsRule.description)
     }
 }
-
-final class PreferConditionListRuleGeneratedTests: SwiftLintTestCase {
-    func testWithDefaultConfiguration() {
-        verifyRule(PreferConditionListRule.description)
-    }
-}

Tests/GeneratedTests/GeneratedTests_07.swift

@@ -7,6 +7,12 @@
 @testable import SwiftLintCore
 import TestHelpers
 
+final class PreferConditionListRuleGeneratedTests: SwiftLintTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(PreferConditionListRule.description)
+    }
+}
+
 final class PreferKeyPathRuleGeneratedTests: SwiftLintTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(PreferKeyPathRule.description)
@@ -150,9 +156,3 @@ final class RedundantNilCoalescingRuleGeneratedTests: SwiftLintTestCase {
         verifyRule(RedundantNilCoalescingRule.description)
     }
 }
-
-final class RedundantObjcAttributeRuleGeneratedTests: SwiftLintTestCase {
-    func testWithDefaultConfiguration() {
-        verifyRule(RedundantObjcAttributeRule.description)
-    }
-}

Tests/GeneratedTests/GeneratedTests_08.swift

@@ -7,6 +7,12 @@
 @testable import SwiftLintCore
 import TestHelpers
 
+final class RedundantObjcAttributeRuleGeneratedTests: SwiftLintTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(RedundantObjcAttributeRule.description)
+    }
+}
+
 final class RedundantSelfInClosureRuleGeneratedTests: SwiftLintTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(RedundantSelfInClosureRule.description)
@@ -150,9 +156,3 @@ final class StrongIBOutletRuleGeneratedTests: SwiftLintTestCase {
         verifyRule(StrongIBOutletRule.description)
     }
 }
-
-final class SuperfluousElseRuleGeneratedTests: SwiftLintTestCase {
-    func testWithDefaultConfiguration() {
-        verifyRule(SuperfluousElseRule.description)
-    }
-}

Tests/GeneratedTests/GeneratedTests_09.swift

@@ -7,6 +7,12 @@
 @testable import SwiftLintCore
 import TestHelpers
 
+final class SuperfluousElseRuleGeneratedTests: SwiftLintTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(SuperfluousElseRule.description)
+    }
+}
+
 final class SwitchCaseAlignmentRuleGeneratedTests: SwiftLintTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(SwitchCaseAlignmentRule.description)
@@ -150,9 +156,3 @@ final class UnneededThrowsRuleGeneratedTests: SwiftLintTestCase {
         verifyRule(UnneededThrowsRule.description)
     }
 }
-
-final class UnownedVariableCaptureRuleGeneratedTests: SwiftLintTestCase {
-    func testWithDefaultConfiguration() {
-        verifyRule(UnownedVariableCaptureRule.description)
-    }
-}

Tests/GeneratedTests/GeneratedTests_10.swift

@@ -7,6 +7,12 @@
 @testable import SwiftLintCore
 import TestHelpers
 
+final class UnownedVariableCaptureRuleGeneratedTests: SwiftLintTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(UnownedVariableCaptureRule.description)
+    }
+}
+
 final class UntypedErrorInCatchRuleGeneratedTests: SwiftLintTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(UntypedErrorInCatchRule.description)

Tests/IntegrationTests/default_rule_configurations.yml

@@ -678,6 +678,12 @@ multiline_arguments_brackets:
   meta:
     opt-in: true
     correctable: false
+multiline_call_arguments:
+  severity: warning
+  allows_single_line: true
+  meta:
+    opt-in: true
+    correctable: false
 multiline_function_chains:
   severity: warning
   meta: