// Copyright 2014 The Flutter Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.

import 'dart:async';

import 'dart:convert';

import 'dart:core' hide print;

import 'dart:io' as io;

import 'package:path/path.dart' as path;

import 'utils.dart';

/// Runs the `executable` and returns standard output as a stream of lines.

///

/// The returned stream reaches its end immediately after the command exits.

///

/// If `expectNonZeroExit` is false and the process exits with a non-zero exit

/// code fails the test immediately by exiting the test process with exit code

/// 1.

Stream<String> runAndGetStdout(String executable, List<String> arguments, {

String? workingDirectory,

Map<String, String>? environment,

bool expectNonZeroExit = false,

}) async* {

final StreamController<String> output = StreamController<String>();

final Future<CommandResult?> command = runCommand(

executable,

arguments,

workingDirectory: workingDirectory,

environment: environment,

expectNonZeroExit: expectNonZeroExit,

// Capture the output so it's not printed to the console by default.

outputMode: OutputMode.capture,

outputListener: (String line, io.Process process) {

output.add(line);

},

);

// Close the stream controller after the command is complete. Otherwise,

// the yield* will never finish.

command.whenComplete(output.close);

yield* output.stream;

}

/// Represents a running process launched using [startCommand].

class Command {

Command._(this.process, this._time, this._savedStdout, this._savedStderr);

/// The raw process that was launched for this command.

final io.Process process;

final Stopwatch _time;

final Future<String> _savedStdout;

final Future<String> _savedStderr;

}

/// The result of running a command using [startCommand] and [runCommand];

class CommandResult {

CommandResult._(this.exitCode, this.elapsedTime, this.flattenedStdout, this.flattenedStderr);

/// The exit code of the process.

final int exitCode;

/// The amount of time it took the process to complete.

final Duration elapsedTime;

/// Standard output decoded as a string using UTF8 decoder.

final String? flattenedStdout;

/// Standard error output decoded as a string using UTF8 decoder.

final String? flattenedStderr;

}

/// Starts the `executable` and returns a command object representing the

/// running process.

///

/// `outputListener` is called for every line of standard output from the

/// process, and is given the [Process] object. This can be used to interrupt

/// an indefinitely running process, for example, by waiting until the process

/// emits certain output.

///

/// `outputMode` controls where the standard output from the command process

/// goes. See [OutputMode].

Future<Command> startCommand(String executable, List<String> arguments, {

String? workingDirectory,

Map<String, String>? environment,

OutputMode outputMode = OutputMode.print,

bool Function(String)? removeLine,

void Function(String, io.Process)? outputListener,

}) async {

final String commandDescription = '${path.relative(executable, from: workingDirectory)} ${arguments.join(' ')}';

final String relativeWorkingDir = path.relative(workingDirectory ?? io.Directory.current.path);

print('RUNNING: cd $cyan$relativeWorkingDir$reset; $green$commandDescription$reset');

final Stopwatch time = Stopwatch()..start();

final io.Process process = await io.Process.start(executable, arguments,

workingDirectory: workingDirectory,

environment: environment,

);

return Command._(

process,

time,

process.stdout

.transform<String>(const Utf8Decoder())

.transform(const LineSplitter())

.where((String line) => removeLine == null || !removeLine(line))

.map<String>((String line) {

final String formattedLine = '$line\n';

if (outputListener != null) {

outputListener(formattedLine, process);

}

switch (outputMode) {

case OutputMode.print:

print(line);

break;

case OutputMode.capture:

break;

}

return line;

})

.join('\n'),

process.stderr

.transform<String>(const Utf8Decoder())

.transform(const LineSplitter())

.map<String>((String line) {

switch (outputMode) {

case OutputMode.print:

print(line);

break;

case OutputMode.capture:

break;

}

return line;

})

.join('\n'),

);

}

/// Runs the `executable` and waits until the process exits.

///

/// If the process exits with a non-zero exit code and `expectNonZeroExit` is

/// false, calls foundError (which does not terminate execution!).

///

/// `outputListener` is called for every line of standard output from the

/// process, and is given the [Process] object. This can be used to interrupt

/// an indefinitely running process, for example, by waiting until the process

/// emits certain output.

///

/// Returns the result of the finished process.

///

/// `outputMode` controls where the standard output from the command process

/// goes. See [OutputMode].

Future<CommandResult> runCommand(String executable, List<String> arguments, {

String? workingDirectory,

Map<String, String>? environment,

bool expectNonZeroExit = false,

int? expectedExitCode,

String? failureMessage,

OutputMode outputMode = OutputMode.print,

bool Function(String)? removeLine,

void Function(String, io.Process)? outputListener,

}) async {

final String commandDescription = '${path.relative(executable, from: workingDirectory)} ${arguments.join(' ')}';

final String relativeWorkingDir = path.relative(workingDirectory ?? io.Directory.current.path);

final Command command = await startCommand(executable, arguments,

workingDirectory: workingDirectory,

environment: environment,

outputMode: outputMode,

removeLine: removeLine,

outputListener: outputListener,

);

final CommandResult result = CommandResult._(

await command.process.exitCode,

command._time.elapsed,

await command._savedStdout,

await command._savedStderr,

);

if ((result.exitCode == 0) == expectNonZeroExit || (expectedExitCode != null && result.exitCode != expectedExitCode)) {

// Print the output when we get unexpected results (unless output was

// printed already).

switch (outputMode) {

case OutputMode.print:

break;

case OutputMode.capture:

print(result.flattenedStdout);

print(result.flattenedStderr);

break;

}

String allOutput;

if (failureMessage == null) {

allOutput = '${result.flattenedStdout}\n${result.flattenedStderr}';

if (allOutput.split('\n').length > 10) {

allOutput = '(stdout/stderr output was more than 10 lines)';

}

} else {

allOutput = '';

}

foundError(<String>[

if (failureMessage != null)

failureMessage,

'${bold}Command: $green$commandDescription$reset',

if (failureMessage == null)

'$bold${red}Command exited with exit code ${result.exitCode} but expected ${expectNonZeroExit ? (expectedExitCode ?? 'non-zero') : 'zero'} exit code.$reset',

'${bold}Working directory: $cyan${path.absolute(relativeWorkingDir)}$reset',

if (allOutput.isNotEmpty)

'${bold}stdout and stderr output:\n$allOutput',

]);

} else {

print('ELAPSED TIME: ${prettyPrintDuration(result.elapsedTime)} for $green$commandDescription$reset in $cyan$relativeWorkingDir$reset');

}

return result;

}

/// Specifies what to do with the command output from [runCommand] and [startCommand].

enum OutputMode {

/// Forwards standard output and standard error streams to the test process'

/// standard output stream (i.e. stderr is redirected to stdout).

///

/// Use this mode if all you want is print the output of the command to the

/// console. The output is no longer available after the process exits.

print,

/// Saves standard output and standard error streams in memory.

///

/// Captured output can be retrieved from the [CommandResult] object.

///

/// Use this mode in tests that need to inspect the output of a command, or

/// when the output should not be printed to console.

capture,

}