Add line number tracking for unused dependencies in Package.swift

Enhanced PackageParser to capture exact line numbers where dependencies are declared and updated output formatters to include line numbers for unused dependency warnings.

Author: tonyarnold

CHANGELOG.md

@@ -20,14 +20,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Fixed incomplete line number capture in Xcode and GitHub Actions output formats
   - Now reports all occurrences of missing dependencies across all source files with correct line numbers
   - Removed premature loop termination that was causing missing line number information
+  - Added line number tracking for unused dependencies in Package.swift files
+  - Enhanced dependency parsing to capture exact line numbers where dependencies are declared
 
 ### Technical Details
 - Enhanced `ImportInfo` model with line number tracking
+- Added `DependencyInfo` model to track dependency line numbers in Package.swift
 - Added `XcodeOutput` module for Xcode-compatible format (`file:line: error: message`)
 - Added `GitHubActionsOutput` module for GitHub Actions format (`::error file=path,line=N::message`)
 - Updated `ImportScanner` to capture line numbers during regex matching
+- Enhanced `PackageParser` with `parseDependencyListWithLineNumbers()` and `findDependencyLineNumber()` methods
 - Extended `DependencyAnalyzer` with `generateXcodeReport()` and `generateGitHubActionsReport()` methods
 - Fixed loop logic in `generateXcodeReport()` and `generateGitHubActionsReport()` to report all import occurrences
+- Updated `Target` model to include `dependencyInfo` array with line number tracking
 - All existing functionality preserved with backward compatibility
 
 ## [1.0.0] - 2025-07-16

Sources/SwiftDependencyAuditLib/DependencyAnalyzer.swift

@@ -231,9 +231,11 @@ public actor DependencyAnalyzer {
             // Generate warnings for unused dependencies
             for unusedDep in result.unusedDependencies.sorted() {
                 let packageFile = URL(fileURLWithPath: packagePath).appendingPathComponent("Package.swift").path
+                let lineNumber = result.target.dependencyInfo.first { $0.name == unusedDep }?.lineNumber
                 let message = XcodeOutput.unusedDependencyWarning(
                     dependency: unusedDep,
-                    packageFile: packageFile
+                    packageFile: packageFile,
+                    line: lineNumber
                 )
                 output.append(message)
             }
@@ -266,9 +268,11 @@ public actor DependencyAnalyzer {
             // Generate warnings for unused dependencies
             for unusedDep in result.unusedDependencies.sorted() {
                 let packageFile = URL(fileURLWithPath: packagePath).appendingPathComponent("Package.swift").path
+                let lineNumber = result.target.dependencyInfo.first { $0.name == unusedDep }?.lineNumber
                 let message = GitHubActionsOutput.unusedDependencyWarning(
                     dependency: unusedDep,
-                    packageFile: packageFile
+                    packageFile: packageFile,
+                    line: lineNumber
                 )
                 output.append(message)
             }

Sources/SwiftDependencyAuditLib/GitHubActionsOutput.swift

@@ -34,9 +34,10 @@ public struct GitHubActionsOutput {
         )
     }
 
-    public static func unusedDependencyWarning(dependency: String, packageFile: String) -> String {
+    public static func unusedDependencyWarning(dependency: String, packageFile: String, line: Int? = nil) -> String {
         return warning(
             file: packageFile,
+            line: line,
             message: "Unused dependency '\(dependency)' is declared but never imported"
         )
     }

Sources/SwiftDependencyAuditLib/Models.swift

@@ -1,15 +1,35 @@
 import Foundation
 
+public struct DependencyInfo: Sendable {
+    public let name: String
+    public let lineNumber: Int?
+    
+    public init(name: String, lineNumber: Int? = nil) {
+        self.name = name
+        self.lineNumber = lineNumber
+    }
+}
+
 public struct Target: Sendable {
     public let name: String
     public let type: TargetType
     public let dependencies: [String]
+    public let dependencyInfo: [DependencyInfo]
     public let path: String?
 
     public init(name: String, type: TargetType, dependencies: [String], path: String?) {
         self.name = name
         self.type = type
         self.dependencies = dependencies
+        self.dependencyInfo = dependencies.map { DependencyInfo(name: $0) }
+        self.path = path
+    }
+    
+    public init(name: String, type: TargetType, dependencyInfo: [DependencyInfo], path: String?) {
+        self.name = name
+        self.type = type
+        self.dependencies = dependencyInfo.map { $0.name }
+        self.dependencyInfo = dependencyInfo
         self.path = path
     }
 

Sources/SwiftDependencyAuditLib/PackageParser.swift

@@ -33,7 +33,7 @@ public actor PackageParser {
         let dependencies = try extractDependencies(from: content)
 
         // Extract targets
-        let targets = try extractTargets(from: content)
+        let targets = try extractTargets(from: content, packageContent: content)
 
         return PackageInfo(
             name: packageName,
@@ -89,7 +89,7 @@ public actor PackageParser {
         return dependencies
     }
 
-    private func extractTargets(from content: String) throws -> [Target] {
+    private func extractTargets(from content: String, packageContent: String) throws -> [Target] {
         var targets: [Target] = []
 
         // Try to extract targets from both patterns:
@@ -117,12 +117,12 @@ public actor PackageParser {
         for match in targetsSection.matches(of: executableRegex) {
             let name = String(match.1)
             let dependenciesStr = String(match.2)
-            let dependencies = parseDependencyList(dependenciesStr)
+            let dependencyInfo = parseDependencyListWithLineNumbers(dependenciesStr, targetName: name, packageContent: packageContent)
 
             targets.append(Target(
                 name: name,
                 type: .executable,
-                dependencies: dependencies,
+                dependencyInfo: dependencyInfo,
                 path: nil
             ))
         }
@@ -131,12 +131,12 @@ public actor PackageParser {
         for match in targetsSection.matches(of: libraryRegex) {
             let name = String(match.1)
             let dependenciesStr = String(match.2)
-            let dependencies = parseDependencyList(dependenciesStr)
+            let dependencyInfo = parseDependencyListWithLineNumbers(dependenciesStr, targetName: name, packageContent: packageContent)
 
             targets.append(Target(
                 name: name,
                 type: .library,
-                dependencies: dependencies,
+                dependencyInfo: dependencyInfo,
                 path: nil
             ))
         }
@@ -145,12 +145,12 @@ public actor PackageParser {
         for match in targetsSection.matches(of: testRegex) {
             let name = String(match.1)
             let dependenciesStr = String(match.2)
-            let dependencies = parseDependencyList(dependenciesStr)
+            let dependencyInfo = parseDependencyListWithLineNumbers(dependenciesStr, targetName: name, packageContent: packageContent)
 
             targets.append(Target(
                 name: name,
                 type: .test,
-                dependencies: dependencies,
+                dependencyInfo: dependencyInfo,
                 path: nil
             ))
         }
@@ -159,12 +159,12 @@ public actor PackageParser {
         for match in targetsSection.matches(of: macroRegex) {
             let name = String(match.1)
             let dependenciesStr = String(match.2)
-            let dependencies = parseDependencyList(dependenciesStr)
+            let dependencyInfo = parseDependencyListWithLineNumbers(dependenciesStr, targetName: name, packageContent: packageContent)
 
             targets.append(Target(
                 name: name,
                 type: .library, // Treat macros as library targets for dependency analysis
-                dependencies: dependencies,
+                dependencyInfo: dependencyInfo,
                 path: nil
             ))
         }
@@ -197,12 +197,12 @@ public actor PackageParser {
         for match in targetsSection.matches(of: pluginRegex) {
             let name = String(match.1)
             let dependenciesStr = String(match.2)
-            let dependencies = parseDependencyList(dependenciesStr)
+            let dependencyInfo = parseDependencyListWithLineNumbers(dependenciesStr, targetName: name, packageContent: packageContent)
 
             targets.append(Target(
                 name: name,
                 type: .plugin,
-                dependencies: dependencies,
+                dependencyInfo: dependencyInfo,
                 path: nil
             ))
         }
@@ -383,6 +383,79 @@ public actor PackageParser {
         return dependencies
     }
 
+    private func parseDependencyListWithLineNumbers(_ dependenciesStr: String, targetName: String, packageContent: String) -> [DependencyInfo] {
+        var dependencyInfos: [DependencyInfo] = []
+        
+        // Get the line numbers for dependencies by searching in the full package content
+        let dependencies = parseDependencyList(dependenciesStr)
+        
+        for dependency in dependencies {
+            if let lineNumber = findDependencyLineNumber(dependency: dependency, targetName: targetName, in: packageContent) {
+                dependencyInfos.append(DependencyInfo(name: dependency, lineNumber: lineNumber))
+            } else {
+                dependencyInfos.append(DependencyInfo(name: dependency, lineNumber: nil))
+            }
+        }
+        
+        return dependencyInfos
+    }
+    
+    private func findDependencyLineNumber(dependency: String, targetName: String, in content: String) -> Int? {
+        let lines = content.components(separatedBy: .newlines)
+        
+        // Find the target declaration first
+        var targetStartLine: Int?
+        var targetEndLine: Int?
+        var braceDepth = 0
+        var inTarget = false
+        
+        for (index, line) in lines.enumerated() {
+            if line.contains("name: \"\(targetName)\"") && (line.contains(".target") || line.contains(".executableTarget") || line.contains(".testTarget") || line.contains(".macro") || line.contains(".plugin")) {
+                targetStartLine = index + 1
+                inTarget = true
+                braceDepth = 0
+            }
+            
+            if inTarget {
+                // Count braces to determine where the target declaration ends
+                for char in line {
+                    if char == "(" {
+                        braceDepth += 1
+                    } else if char == ")" {
+                        braceDepth -= 1
+                        if braceDepth == 0 {
+                            targetEndLine = index + 1
+                            break
+                        }
+                    }
+                }
+                
+                if let targetEndLine = targetEndLine {
+                    break
+                }
+            }
+        }
+        
+        // Search for the dependency within the target declaration
+        if let startLine = targetStartLine, let endLine = targetEndLine {
+            for lineIndex in (startLine - 1)..<min(endLine, lines.count) {
+                let line = lines[lineIndex]
+                // Look for the dependency name in quotes or as a product name
+                if line.contains("\"\(dependency)\"") {
+                    return lineIndex + 1
+                }
+            }
+        }
+        
+        return nil
+    }
+    
+    private func findLineNumber(for range: Range<String.Index>, in content: String) -> Int? {
+        let prefix = content[..<range.lowerBound]
+        let lineNumber = prefix.components(separatedBy: .newlines).count
+        return lineNumber
+    }
+    
     private func repoNameToModuleName(_ repoName: String) -> String {
         // Convert common repository naming patterns to module names
         let cleanedName = repoName

Sources/SwiftDependencyAuditLib/XcodeOutput.swift

@@ -34,9 +34,10 @@ public struct XcodeOutput {
         )
     }
 
-    public static func unusedDependencyWarning(dependency: String, packageFile: String) -> String {
+    public static func unusedDependencyWarning(dependency: String, packageFile: String, line: Int? = nil) -> String {
         return warning(
             file: packageFile,
+            line: line,
             message: "Unused dependency '\(dependency)' is declared but never imported"
         )
     }