remove preconditions b/c their failures are impossible to debug

pinpill/pinpill/Configuration/PinpillConfiguration.swift

@@ -11,6 +11,7 @@ import Foundation
 class PinpillConfiguration: Codable {
     enum PinpillConfigurationError: Error {
         case missingRequiredConfig(String)
+        case invalidConfig(String)
     }
 
     static let kDefaultHeadless = true
@@ -94,7 +95,7 @@ class PinpillConfiguration: Codable {
         Logger.verbose(msg: "Found xcode path: \(xcodeTask.stdOut)")
         let xcodeURL = URL(fileURLWithPath: xcodeTask.stdOut.trimmingCharacters(in: .whitespacesAndNewlines))
 
-        let urls = PinpillURLs(
+        let urls = try PinpillURLs(
             fileManager: FileManager.default,
             testBundleURL: testBundleURL,
             appBundleURL: appBundleURL,
@@ -104,7 +105,7 @@ class PinpillConfiguration: Codable {
             outputURL: outputURL,
             simulatorPreferencesURL: simulatorPreferencesURL
         )
-        return PinpillConfiguration(
+        return try PinpillConfiguration(
             headless: headless,
             maxSims: maxSims,
             maxRetries: maxRetries,
@@ -131,18 +132,30 @@ class PinpillConfiguration: Codable {
         urls: PinpillURLs,
         recordVideo: Bool,
         recordScreenshot: Bool
-    ) {
+    ) throws {
         self.headless = headless
-        precondition(maxSims > 0, "maxSims must be a positive integer. Got \(maxSims)")
+        if (maxSims <= 0) {
+            throw PinpillConfigurationError.invalidConfig("maxSims must be a positive integer. Got \(maxSims)")
+        }
         self.maxSims = maxSims
-        precondition(maxRetries >= 0, "numTestRuns must be a non-negative integer. Got \(maxRetries)")
+
+        if (maxRetries < 0) {
+            throw PinpillConfigurationError.invalidConfig("numTestRuns must be a non-negative integer. Got \(maxRetries)")
+        }
         self.maxRetries = maxRetries
-        precondition(numTestRuns > 0, "numTestRuns must be a positive integer. Got \(numTestRuns)")
+
+        if (numTestRuns <= 0) {
+            throw PinpillConfigurationError.invalidConfig("numTestRuns must be a positive integer. Got \(numTestRuns)")
+        }
         self.numTestRuns = numTestRuns
         self.device = device
         self.runtime = runtime
-        precondition(!testTasks.isEmpty, "Must contain at least one test task")
+
+        if (testTasks.isEmpty) {
+            throw PinpillConfigurationError.invalidConfig("testTasks must be non-empty.")
+        }
         self.testTasks = testTasks
+
         self.environment = environment
         self.urls = urls
         self.recordVideo = recordVideo

pinpill/pinpill/Configuration/PinpillURLs.swift

@@ -9,6 +9,10 @@
 import Foundation
 
 class PinpillURLs: Codable {
+    enum PinpillURLError: Error {
+        case fileNotFoundError(String)
+    }
+
     let testBundleURL: URL
     let appBundleURL: URL
     let xcTestRunURL: URL
@@ -17,33 +21,25 @@ class PinpillURLs: Codable {
     let bpURL: URL
     let outputURL: URL
     let simulatorPreferencesURL: URL
-
     let simulatorURL: URL
 
-    init(fileManager: FileManager, testBundleURL: URL, appBundleURL: URL, xcTestRunURL: URL, xcodeURL: URL, bpURL: URL, outputURL: URL, simulatorPreferencesURL: URL) {
-        precondition(fileManager.fileExists(atPath: testBundleURL.path), "Test bundle not found at path \(testBundleURL.path)")
+    init(fileManager: FileManager, testBundleURL: URL, appBundleURL: URL, xcTestRunURL: URL, xcodeURL: URL, bpURL: URL, outputURL: URL, simulatorPreferencesURL: URL) throws {
         self.testBundleURL = testBundleURL
-
-        precondition(fileManager.fileExists(atPath: appBundleURL.path), "App bundle not found at path \(appBundleURL.path)")
         self.appBundleURL = appBundleURL
-
-        precondition(fileManager.fileExists(atPath: xcTestRunURL.path), ".xctestrun not found at path \(xcTestRunURL.path)")
         self.xcTestRunURL = xcTestRunURL
-
-        precondition(fileManager.fileExists(atPath: xcodeURL.path), "xcode not found at path \(xcodeURL.path)")
         self.xcodeURL = xcodeURL
-
-        precondition(fileManager.fileExists(atPath: bpURL.path), "bp executable not found at path \(bpURL.path)")
         self.bpURL = bpURL
-
-        // Don't verify this exists because bp will create it for us if it's missing.
         self.outputURL = outputURL
-
-        precondition(fileManager.fileExists(atPath: simulatorPreferencesURL.path), "simulator preferences not found at path \(simulatorPreferencesURL.path)")
         self.simulatorPreferencesURL = simulatorPreferencesURL
-
         testRootURL = xcTestRunURL.deletingLastPathComponent()
         simulatorURL = xcodeURL.appendingPathComponent("/Applications/Simulator.app/Contents/MacOS/Simulator")
+
+        try checkExists(fileManager: fileManager, path: testBundleURL, description: "test bundle")
+        try checkExists(fileManager: fileManager, path: appBundleURL, description: "app bundle")
+        try checkExists(fileManager: fileManager, path: xcTestRunURL, description: ".xctestrun")
+        try checkExists(fileManager: fileManager, path: testBundleURL, description: "xcode")
+        try checkExists(fileManager: fileManager, path: bpURL, description: "bp executable")
+        try checkExists(fileManager: fileManager, path: simulatorPreferencesURL, description: "simulator preferences")
     }
 
     func findXCTestURLs() -> [URL] {
@@ -58,4 +54,10 @@ class PinpillURLs: Codable {
 
         return pluginURLs.filter { $0.pathExtension == "xctest" }
     }
+
+    func checkExists(fileManager: FileManager, path: URL, description: String) throws {
+        if(!fileManager.fileExists(atPath: path.path)) {
+            throw PinpillURLError.fileNotFoundError("\(description) not found at path \(path)")
+        }
+    }
 }

pinpill/pinpill/PinpillCLI.swift

@@ -22,10 +22,10 @@ struct PinpillCLI: ParsableCommand {
     var headless: Bool = false
 
     @Flag(help: "Disable saving videos of test runs.")
-    var noRecordVideo: Bool
+    var noRecordVideo: Bool = false
 
     @Flag(help: "Disable saving screenshots of failed UI tests.")
-    var noRecordScreenshot: Bool
+    var noRecordScreenshot: Bool = false
 
     @Option(help: "Maximum number of concurrent simulators")
     var maxSims: Int?
@@ -113,15 +113,18 @@ struct PinpillCLI: ParsableCommand {
 
     func readArgumentsFromFile(fileManager: FileManager, path: String) -> JSONPinpillArguments? {
         let configURL = URL(fileURLWithPath: path)
-        precondition(fileManager.fileExists(atPath: configURL.path), "config file not found at path \(configURL.path)")
+        if (!fileManager.fileExists(atPath: configURL.path)) {
+            Logger.error(msg: "Config file not found at path \(configURL.path)")
+            return nil
+        }
         let decoder = JSONDecoder()
         do {
             let jsonArgs = try decoder.decode(JSONPinpillArguments.self, from: Data(contentsOf: configURL))
             Logger.verbose(msg: "Parsed arguments from file:")
             Logger.verbose(msg: jsonArgs.toJSON())
             return jsonArgs
         } catch {
-            Logger.error(msg: "error: failed to decode arguments from file at \(path).")
+            Logger.error(msg: "Failed to decode arguments from file at \(path).")
             return nil
         }
     }