multiline_parameters: check function call arguments (optional via check_calls)

CHANGELOG.md

@@ -101,6 +101,13 @@
 * Rewrite `quick_discouraged_call` rule with SwiftSyntax.  
   [SimplyDanny](https://github.com/SimplyDanny)
 
+* `multiline_parameters`: add optional checks for **function call arguments**.
+  When `check_calls` is enabled, the rule enforces that call arguments are either
+  all on one line (subject to `max_number_of_single_line_parameters`) or
+  one per line, mirroring the behavior for function/initializer declarations.
+  Trailing closures are ignored by default.
+  [GandaLF2006](https://github.com/GandaLF2006)
+
 ### Bug Fixes
 
 * Ensure that header matched against always end in a newline in `file_header` rule.  

Source/SwiftLintBuiltInRules/Rules/RuleConfigurations/MultilineParametersConfiguration.swift

@@ -10,8 +10,19 @@ struct MultilineParametersConfiguration: SeverityBasedRuleConfiguration {
     private(set) var allowsSingleLine = true
     @ConfigurationElement(key: "max_number_of_single_line_parameters")
     private(set) var maxNumberOfSingleLineParameters: Int?
+    @ConfigurationElement(key: "check_calls")
+    private(set) var checkCalls = false
 
     func validate() throws {
+        if checkCalls, maxNumberOfSingleLineParameters == nil {
+            Issue.inconsistentConfiguration(
+                ruleID: Parent.identifier,
+                message: """
+                         Option '\($checkCalls.key)' has no effect when \
+                         '\($maxNumberOfSingleLineParameters.key)' is nil.
+                         """
+            ).print()
+        }
         guard let maxNumberOfSingleLineParameters else {
             return
         }
@@ -32,5 +43,15 @@ struct MultilineParametersConfiguration: SeverityBasedRuleConfiguration {
                          """
             ).print()
         }
+
+        if checkCalls, !allowsSingleLine {
+            Issue.inconsistentConfiguration(
+                ruleID: Parent.identifier,
+                message: """
+                         Option '\($checkCalls.key)' has no effect when \
+                         '\($allowsSingleLine.key)' is false.
+                         """
+            ).print()
+        }
     }
 }

Source/SwiftLintBuiltInRules/Rules/Style/MultilineParametersRule.swift

@@ -7,7 +7,9 @@ struct MultilineParametersRule: Rule {
     static let description = RuleDescription(
         identifier: "multiline_parameters",
         name: "Multiline Parameters",
-        description: "Functions and methods parameters should be either on the same line, or one per line",
+        description: """
+            Functions, initializers, and function call arguments should be either on the same line, or one per line
+            """,
         kind: .style,
         nonTriggeringExamples: MultilineParametersRuleExamples.nonTriggeringExamples,
         triggeringExamples: MultilineParametersRuleExamples.triggeringExamples
@@ -28,8 +30,28 @@ private extension MultilineParametersRule {
             }
         }
 
+        override func visitPost(_ node: FunctionCallExprSyntax) {
+            guard node.arguments.isNotEmpty else { return }
+            guard configuration.checkCalls else { return }
+            guard node.trailingClosure == nil else { return }
+
+            if containsViolation(for: node.arguments) {
+                let anchor = node.calledExpression.positionAfterSkippingLeadingTrivia
+                violations.append(anchor)
+            }
+        }
+
         private func containsViolation(for signature: FunctionSignatureSyntax) -> Bool {
             let parameterPositions = signature.parameterClause.parameters.map(\.positionAfterSkippingLeadingTrivia)
+            return containsViolation(parameterPositions: parameterPositions)
+        }
+
+        private func containsViolation(for arguments: LabeledExprListSyntax) -> Bool {
+            let argumentPositions = arguments.map(\.positionAfterSkippingLeadingTrivia)
+            return containsViolation(parameterPositions: argumentPositions)
+        }
+
+        private func containsViolation(parameterPositions: [AbsolutePosition]) -> Bool {
             guard parameterPositions.isNotEmpty else {
                 return false
             }

Source/SwiftLintBuiltInRules/Rules/Style/MultilineParametersRuleExamples.swift

@@ -213,6 +213,20 @@ internal struct MultilineParametersRuleExamples {
             param3: [String]
         ) { }
         """, configuration: ["max_number_of_single_line_parameters": 2]),
+        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]),
     ]
 
     static let triggeringExamples: [Example] = [
@@ -360,6 +374,27 @@ internal struct MultilineParametersRuleExamples {
        """, configuration: ["max_number_of_single_line_parameters": 3]),
         Example("""
         func ↓foo(param1: Int, param2: Bool, param3: [String]) { }
-        """, configuration: ["max_number_of_single_line_parameters": 2]),
+        """, configuration: [
+            "max_number_of_single_line_parameters": 2,
+            "check_calls": true,
+        ]),
+        Example("↓foo(param1: 1, param2: false, param3: [])",
+                configuration: [
+                    "max_number_of_single_line_parameters": 2,
+                    "check_calls": true,
+                ]),
+        Example("""
+        func ↓foo(param1: Int,
+                  param2: Bool, param3: [String]) { }
+       """, configuration: [
+        "max_number_of_single_line_parameters": 3,
+        "check_calls": true,
+       ]),
+        Example("""
+        ↓foo(param1: Int, param2: Bool, param3: [String])
+        """, configuration: [
+            "max_number_of_single_line_parameters": 2,
+            "check_calls": true,
+        ]),
     ]
 }

Tests/IntegrationTests/default_rule_configurations.yml

@@ -684,6 +684,7 @@ multiline_literal_brackets:
 multiline_parameters:
   severity: warning
   allows_single_line: true
+  check_calls: false
   meta:
     opt-in: true
     correctable: false