changes to run function for stdin pipe

Author: saehejkang

Tests/CLITests/Subcommands/Build/CLIBuildBase.swift

@@ -171,11 +171,7 @@ class TestCLIBuildBase: CLITest {
 
         args.append(contentsOf: otherArgs)
 
-        let stdinPipe = Pipe()
-        try stdinPipe.fileHandleForWriting.write(contentsOf: Data(dockerfileContents.utf8))
-        stdinPipe.fileHandleForWriting.closeFile()
-
-        let response = try run(arguments: args, stdin: stdinPipe)
+        let response = try run(arguments: args, stdin: dockerfileContents)
         if response.status != 0 {
             throw CLIError.executionFailed("build failed: stdout=\(response.output) stderr=\(response.error)")
         }

Tests/CLITests/Utilities/CLITest.swift

@@ -110,22 +110,25 @@ class CLITest {
         }
     }
 
-    func run(arguments: [String], stdin: Pipe? = nil, currentDirectory: URL? = nil) throws -> (output: String, error: String, status: Int32) {
+    func run(arguments: [String], stdin: String? = nil, currentDirectory: URL? = nil) throws -> (output: String, error: String, status: Int32) {
         let process = Process()
         process.executableURL = try executablePath
         process.arguments = arguments
         if let directory = currentDirectory {
             process.currentDirectoryURL = directory
         }
 
+        let inputPipe = Pipe()
         let outputPipe = Pipe()
         let errorPipe = Pipe()
+        process.standardInput = inputPipe
         process.standardOutput = outputPipe
         process.standardError = errorPipe
 
-        if let stdin = stdin {
-            process.standardInput = stdin
+        if let data = stdin?.data(using: .utf8) {
+            inputPipe.fileHandleForWriting.write(data)
         }
+        inputPipe.fileHandleForWriting.closeFile()
 
         do {
             try process.run()