Command plugin should skip irrelevant targets when run without --target argument

Plugins/OpenAPIGeneratorCommand/plugin.swift

@@ -65,27 +65,39 @@ extension SwiftOpenAPIGeneratorPlugin: CommandPlugin {
         var hadASuccessfulRun = false
 
         for target in targets {
-            print("Considering target '\(target.name)':")
+            log("Considering target '\(target.name)':")
             guard let swiftTarget = target as? SwiftSourceModuleTarget else {
-                print("- Not a swift source module. Can't generate OpenAPI code.")
+                log("- Not a swift source module. Can't generate OpenAPI code.")
                 continue
             }
             do {
-                print("- Trying OpenAPI code generation.")
+                log("- Trying OpenAPI code generation.")
                 try runCommand(
                     targetWorkingDirectory: target.directory,
                     tool: context.tool,
                     sourceFiles: swiftTarget.sourceFiles,
                     targetName: target.name
                 )
-                print("- ✅ OpenAPI code generation for target '\(target.name)' successfully completed.")
+                log("- ✅ OpenAPI code generation for target '\(target.name)' successfully completed.")
                 hadASuccessfulRun = true
             } catch let error as PluginError {
+                if targetNameArguments.isEmpty, case .fileErrors(let errors) = error,
+                    Set(errors.map(\.fileKind)) == Set(FileError.Kind.allCases),
+                    errors.map(\.issue).allSatisfy({ $0 == FileError.Issue.noFilesFound })
+                {
+                    // The command plugin was run with no --target argument so its looping over all targets.
+                    // If a target does not have any of the required files, this should only be considered an error
+                    // if the plugin is being explicitly run on a target, either using the build plugin, or using the
+                    // command plugin with a --target argument.
+                    log("- Skipping because target isn't configured for OpenAPI code generation.")
+                    continue
+                }
+
                 if error.isMisconfigurationError {
-                    print("- Stopping because target isn't configured for OpenAPI code generation.")
+                    log("- Stopping because target is misconfigured for OpenAPI code generation.")
                     throw error
                 } else {
-                    print("- OpenAPI code generation failed with error.")
+                    log("- OpenAPI code generation failed with error.")
                     throw error
                 }
             }
@@ -94,3 +106,7 @@ extension SwiftOpenAPIGeneratorPlugin: CommandPlugin {
         guard hadASuccessfulRun else { throw PluginError.noTargetsWithExpectedFiles(targetNames: targets.map(\.name)) }
     }
 }
+
+private func log(_ message: @autoclosure () -> String) {
+    FileHandle.standardError.write(Data(message().appending("\n").utf8))
+}

Plugins/PluginsShared/PluginError.swift

@@ -14,7 +14,7 @@
 import PackagePlugin
 import Foundation
 
-enum PluginError: Swift.Error, CustomStringConvertible, LocalizedError {
+enum PluginError: Swift.Error, Equatable, CustomStringConvertible, LocalizedError {
     case incompatibleTarget(name: String)
     case generatorFailure(targetName: String)
     case noTargetsWithExpectedFiles(targetNames: [String])
@@ -55,10 +55,10 @@ enum PluginError: Swift.Error, CustomStringConvertible, LocalizedError {
     }
 }
 
-struct FileError: Swift.Error, CustomStringConvertible, LocalizedError {
+struct FileError: Swift.Error, Equatable, CustomStringConvertible, LocalizedError {
 
     /// The kind of the file.
-    enum Kind: CaseIterable {
+    enum Kind: Equatable, CaseIterable {
         /// Config file.
         case config
         /// OpenAPI document file.
@@ -73,7 +73,7 @@ struct FileError: Swift.Error, CustomStringConvertible, LocalizedError {
     }
 
     /// Encountered issue.
-    enum Issue {
+    enum Issue: Equatable {
         /// File wasn't found.
         case noFilesFound
         /// More than 1 file found.

scripts/run-integration-test.sh

@@ -45,4 +45,8 @@ swift package --package-path "${INTEGRATION_TEST_PACKAGE_PATH}" \
 log "Building integration test package: ${INTEGRATION_TEST_PACKAGE_PATH}"
 swift build --package-path "${INTEGRATION_TEST_PACKAGE_PATH}"
 
+log "Running command plugin on integration test package: ${INTEGRATION_TEST_PACKAGE_PATH}"
+swift package --package-path "${INTEGRATION_TEST_PACKAGE_PATH}" \
+ --allow-writing-to-package-directory generate-code-from-openapi
+
 log "✅ Successfully built integration test package."