如何为JUnit4模拟多个用户输入

Question

'我有多个用户输入提示，是否可以形成一个用户输入列表，并让它在时间到来时提取相应的输入？'

@Test
public void test1() {


String simulatedUserInput = "1n"+"2n"+"3n" ;

InputStream savedStandardInputStream = System.in;
System.setIn(new ByteArrayInputStream(simulatedUserInput.getBytes()));
// code that needs multiple user inputs
System.setIn(savedStandardInputStream);

ByteArrayOutputStream out = new ByteArrayOutputStream(); 
System.setOut(new PrintStream(out));

String[] args = {} ;
Demo.main(args);

String consoleOutPutString ="Enter side 1: "+ System.getProperty("line.separator")+"1"+ System.getProperty("line.separator"); 
consoleOutPutString +="Enter side 2: "+ System.getProperty("line.separator")+"2"+ System.getProperty("line.separator"); 
consoleOutPutString +="Enter side 3: "+ System.getProperty("line.separator")+"3"+ System.getProperty("line.separator"); 
consoleOutPutString +="This is not a triangle."+ System.getProperty("line.separator"); 
assertEquals(consoleOutPutString, out.toString());


}

}

"此代码不起作用">

在此处输入图像描述

Answer 1

您可以使用term4j:包装System.in

public static void main(String[] args) {
new YourApp(
new Stdin(),   // Stdin is a wrapper for Scanner.in
new Stdout()   // Stdout is a wrapper for System.out
).start(args);
}

这是Stdin的单元测试

@Test
public void readFromStdin() {
/**
* The standard system input (stdin) which keeps the expected input lines in-memory
*  instead of direct manipulations with {@link System#in} or {@link Console}.
*/
final Input stdin = new Stdin(
new InputOf(String.format("line1%nline2"))
);
MatcherAssert.assertThat(
"The 1st line was read from console",
stdin.value(),
new IsEqual("line1")
);
MatcherAssert.assertThat(
"The 2nd line was read from console",
stdin.value(),
new IsEqual("line2")
);
}

这是Stdout的单元测试

/**
* Simulate the STD print procedure using {@link StringWriter}.
*/
@Test
public void printToWriter() {
// Write 4 lines delimited by `n` or `rn` to the StringWriter
final StringWriter swter = new StringWriter();
final Output std = new Stdout(swter);
std.print("line1", "line2");
std.print("line3", "line4");
// Check that the result string has 4 lines
MatcherAssert.assertThat(
"4 lines of text were printed to the output",
swter.toString(),
new HasLines("line1", "line2", "line3", "line4")
);
}

对于您的情况，您可以使用以下代码在测试中模拟System.in和System.out：

public class YourAppTest {
@Test
public void skeleton(){
Input stdin = new Stdin(  
new InputOf(String.format("line1%nline2"))  // expected multiple user input from terminal
);
StringWriter stdout = new StringWriter();  // the app output to terminal
new YourApp(stdin, new Stdout(stdout))
.start(...);
MatcherAssert.assertThat(
"4 lines of text were printed to the output",
out.toString(),
new HasLines("line1", "line2", "line3", "line4")
);
}
}