Added ability to read package manifest json from provided path

Sources/Frontend/Commands/ScanCommand.swift

@@ -114,6 +114,9 @@ struct ScanCommand: FrontendCommand {
     @Flag(help: "Only output results")
     var quiet: Bool = defaultConfiguration.$quiet.defaultValue
 
+    @Option(parsing: .upToNextOption, help: "JSON package manifest path (obtained using `swift package describe --type json` or manually)")
+    var jsonPackageManifestPath: [FilePath] = defaultConfiguration.$jsonPackageManifestPath.defaultValue
+
     private static let defaultConfiguration = Configuration()
 
     func run() throws {
@@ -162,6 +165,7 @@ struct ScanCommand: FrontendCommand {
         configuration.apply(\.$buildArguments, buildArguments)
         configuration.apply(\.$relativeResults, relativeResults)
         configuration.apply(\.$retainCodableProperties, retainCodableProperties)
+        configuration.apply(\.$jsonPackageManifestPath, jsonPackageManifestPath)
 
         try scanBehavior.main { project in
             try Scan().perform(project: project)

Sources/PeripheryKit/SPM/SPM.swift

@@ -10,12 +10,21 @@ public struct SPM {
     }
 
     public struct Package: Decodable {
-        public static func load() throws -> Self {
+        public static func load(jsonPackageManifestPath: [FilePath] = []) throws -> Self {
             Logger().contextualized(with: "spm:package").debug("Loading \(FilePath.current)")
-            let jsonString = try Shell.shared.exec(["swift", "package", "describe", "--type", "json"], stderr: false)
 
-            guard let jsonData = jsonString.data(using: .utf8) else {
-                throw PeripheryError.packageError(message: "Failed to read swift package description.")
+            let jsonData: Data
+
+            if let path = jsonPackageManifestPath.first {
+                jsonData = try Data(contentsOf: path.url)
+            } else {
+                let jsonString = try Shell.shared.exec(["swift", "package", "describe", "--type", "json"], stderr: false)
+
+                guard let data = jsonString.data(using: .utf8) else {
+                    throw PeripheryError.packageError(message: "Failed to read swift package description.")
+                }
+
+                jsonData = data
             }
 
             let decoder = JSONDecoder()

Sources/PeripheryKit/SPM/SPMProjectDriver.swift

@@ -5,7 +5,7 @@ import Shared
 public final class SPMProjectDriver {
     public static func build() throws -> Self {
         let configuration = Configuration.shared
-        let package = try SPM.Package.load()
+        let package = try SPM.Package.load(jsonPackageManifestPath: configuration.jsonPackageManifestPath)
         let targets: [SPM.Target]
 
         if !configuration.schemes.isEmpty {

Sources/Shared/Configuration.swift

@@ -110,6 +110,9 @@ public final class Configuration {
     @Setting(key: "relative_results", defaultValue: false)
     public var relativeResults: Bool
 
+    @Setting(key: "json_package_manifest_path", defaultValue: [])
+    public var jsonPackageManifestPath: [FilePath]
+
     // Non user facing.
     public var guidedSetup: Bool = false
     public var removalOutputBasePath: FilePath?