Rework output methods to allow quiet and async sequence variants

Author: cmcgee1024

Sources/SwiftlyCore/ModeledCommandLine.swift

@@ -2,12 +2,6 @@ import Foundation
 import Subprocess
 import SystemPackage
 
-public enum CommandLineError: Error {
-    case invalidArgs
-    case errorExit(exitCode: Int32, program: String)
-    case unknownVersion
-}
-
 public protocol Runnable {
     func config() -> Configuration
 }
@@ -24,6 +18,7 @@ extension Runnable {
         error: Error = .discarded
     ) async throws -> CollectedResult<Output, Error> {
         var c = self.config()
+
         // TODO: someday the configuration might have its own environment from the modeled commands. That will require this to be able to merge the environment from the commands with the provided environment.
         c.environment = environment
 
@@ -40,6 +35,7 @@ extension Runnable {
         quiet: Bool = false,
     ) async throws {
         var c = self.config()
+
         // TODO: someday the configuration might have its own environment from the modeled commands. That will require this to be able to merge the environment from the commands with the provided environment.
         c.environment = environment
 
@@ -59,23 +55,78 @@ extension Runnable {
 
 public protocol Output: Runnable {}
 
-// TODO: look into making this something that can be Decodable (i.e. streamable)
 extension Output {
     public func output(
         environment: Environment = .inherit,
-        limit: Int
+        limit: Int,
+        quiet: Bool = false
     ) async throws -> String? {
         var c = self.config()
+
         // TODO: someday the configuration might have its own environment from the modeled commands. That will require this to be able to merge the environment from the commands with the provided environment.
         c.environment = environment
 
-        let output = try await Subprocess.run(
-            self.config(),
-            output: .string(limit: limit),
-            error: .standardError
-        )
+        if !quiet {
+            let result = try await Subprocess.run(
+                self.config(),
+                output: .string(limit: limit),
+                error: .standardError
+            )
 
-        return output.standardOutput
+            if !result.terminationStatus.isSuccess {
+                throw RunProgramError(terminationStatus: result.terminationStatus, config: c)
+            }
+
+            return result.standardOutput
+        } else {
+            let result = try await Subprocess.run(
+                self.config(),
+                output: .string(limit: limit),
+                error: .discarded
+            )
+
+            if !result.terminationStatus.isSuccess {
+                throw RunProgramError(terminationStatus: result.terminationStatus, config: c)
+            }
+
+            return result.standardOutput
+        }
+    }
+
+    public func output(
+        environment: Environment = .inherit,
+        limit _: Int,
+        quiet: Bool = false,
+        body: (AsyncBufferSequence) -> Void
+    ) async throws {
+        var c = self.config()
+
+        // TODO: someday the configuration might have its own environment from the modeled commands. That will require this to be able to merge the environment from the commands with the provided environment.
+        c.environment = environment
+
+        if !quiet {
+            let result = try await Subprocess.run(
+                self.config(),
+                error: .standardError
+            ) { _, sequence in
+                body(sequence)
+            }
+
+            if !result.terminationStatus.isSuccess {
+                throw RunProgramError(terminationStatus: result.terminationStatus, config: c)
+            }
+        } else {
+            let result = try await Subprocess.run(
+                self.config(),
+                error: .discarded
+            ) { _, sequence in
+                body(sequence)
+            }
+
+            if !result.terminationStatus.isSuccess {
+                throw RunProgramError(terminationStatus: result.terminationStatus, config: c)
+            }
+        }
     }
 }