config terminal simulation for specific stdios only

tests/by-util/test_nohup.rs

@@ -45,7 +45,7 @@ fn test_nohup_with_pseudo_terminal_emulation_on_stdin_stdout_stderr_get_replaced
     let result = ts
         .ucmd()
         .terminal_simulation(true)
-        .args(&["sh", "is_atty.sh"])
+        .args(&["sh", "is_a_tty.sh"])
         .succeeds();
 
     assert_eq!(
@@ -58,6 +58,6 @@ fn test_nohup_with_pseudo_terminal_emulation_on_stdin_stdout_stderr_get_replaced
     // this proves that nohup was exchanging the stdio file descriptors
     assert_eq!(
         std::fs::read_to_string(ts.fixtures.plus_as_string("nohup.out")).unwrap(),
-        "stdin is not atty\nstdout is not atty\nstderr is not atty\n"
+        "stdin is not a tty\nstdout is not a tty\nstderr is not a tty\n"
     );
 }

tests/common/util.rs

@@ -1207,6 +1207,15 @@ impl TestScenario {
     }
 }
 
+#[cfg(unix)]
+#[derive(Debug, Default)]
+pub struct TerminalSimulation {
+    size: Option<libc::winsize>,
+    stdin: bool,
+    stdout: bool,
+    stderr: bool,
+}
+
 /// A `UCommand` is a builder wrapping an individual Command that provides several additional features:
 /// 1. it has convenience functions that are more ergonomic to use for piping in stdin, spawning the command
 ///       and asserting on the results.
@@ -1242,9 +1251,7 @@ pub struct UCommand {
     stderr_to_stdout: bool,
     timeout: Option<Duration>,
     #[cfg(unix)]
-    terminal_simulation: bool,
+    terminal_simulation: Option<TerminalSimulation>,
-    #[cfg(unix)]
-    terminal_size: Option<libc::winsize>,
     tmpd: Option<Rc<TempDir>>, // drop last
 }
 
@@ -1425,22 +1432,32 @@ impl UCommand {
 
     /// Set if process should be run in a simulated terminal
     ///
-    /// This is useful to test behavior that is only active if [`stdout.is_terminal()`] is [`true`].
+    /// This is useful to test behavior that is only active if e.g. [`stdout.is_terminal()`] is [`true`].
+    /// This function uses default terminal size and attaches stdin, stdout and stderr to that terminal.
+    /// For more control over the terminal simulation, use `terminal_sim_stdio`
     /// (unix: pty, windows: ConPTY[not yet supported])
     #[cfg(unix)]
     pub fn terminal_simulation(&mut self, enable: bool) -> &mut Self {
-        self.terminal_simulation = enable;
+        if enable {
+            self.terminal_simulation = Some(TerminalSimulation {
+                stdin: true,
+                stdout: true,
+                stderr: true,
+                ..Default::default()
+            });
+        } else {
+            self.terminal_simulation = None;
+        }
         self
     }
 
-    /// Set if process should be run in a simulated terminal with specific size
+    /// Allows to simulate a terminal use-case with specific properties.
     ///
-    /// This is useful to test behavior that is only active if [`stdout.is_terminal()`] is [`true`].
+    /// This is useful to test behavior that is only active if e.g. [`stdout.is_terminal()`] is [`true`].
-    /// And the size of the terminal matters additionally.
+    /// This function allows to set a specific size and to attach the terminal to only parts of the in/out.
     #[cfg(unix)]
-    pub fn terminal_size(&mut self, win_size: libc::winsize) -> &mut Self {
+    pub fn terminal_sim_stdio(&mut self, config: TerminalSimulation) -> &mut Self {
-        self.terminal_simulation(true);
+        self.terminal_simulation = Some(config);
-        self.terminal_size = Some(win_size);
         self
     }
 
@@ -1628,35 +1645,48 @@ impl UCommand {
         };
 
         #[cfg(unix)]
-        if self.terminal_simulation {
+        if let Some(simulated_terminal) = &self.terminal_simulation {
-            let terminal_size = self.terminal_size.unwrap_or(libc::winsize {
+            let terminal_size = simulated_terminal.size.unwrap_or(libc::winsize {
                 ws_col: 80,
                 ws_row: 30,
                 ws_xpixel: 80 * 8,
                 ws_ypixel: 30 * 10,
             });
 
-            let OpenptyResult {
+            if simulated_terminal.stdin {
-                slave: pi_slave,
+                let OpenptyResult {
-                master: pi_master,
+                    slave: pi_slave,
-            } = nix::pty::openpty(&terminal_size, None).unwrap();
+                    master: pi_master,
-            let OpenptyResult {
+                } = nix::pty::openpty(&terminal_size, None).unwrap();
-                slave: po_slave,
+                stdin_pty = Some(File::from(pi_master));
-                master: po_master,
+                command.stdin(pi_slave);
-            } = nix::pty::openpty(&terminal_size, None).unwrap();
+            }
-            let OpenptyResult {
-                slave: pe_slave,
-                master: pe_master,
-            } = nix::pty::openpty(&terminal_size, None).unwrap();
 
-            stdin_pty = Some(File::from(pi_master));
+            if simulated_terminal.stdout {
+                let OpenptyResult {
+                    slave: po_slave,
+                    master: po_master,
+                } = nix::pty::openpty(&terminal_size, None).unwrap();
+                captured_stdout = self.spawn_reader_thread(
+                    captured_stdout,
+                    po_master,
+                    "stdout_reader".to_string(),
+                );
+                command.stdout(po_slave);
+            }
 
-            captured_stdout =
+            if simulated_terminal.stderr {
-                self.spawn_reader_thread(captured_stdout, po_master, "stdout_reader".to_string());
+                let OpenptyResult {
-            captured_stderr =
+                    slave: pe_slave,
-                self.spawn_reader_thread(captured_stderr, pe_master, "stderr_reader".to_string());
+                    master: pe_master,
-
+                } = nix::pty::openpty(&terminal_size, None).unwrap();
-            command.stdin(pi_slave).stdout(po_slave).stderr(pe_slave);
+                captured_stderr = self.spawn_reader_thread(
+                    captured_stderr,
+                    pe_master,
+                    "stderr_reader".to_string(),
+                );
+                command.stderr(pe_slave);
+            }
         }
 
         #[cfg(unix)]
@@ -3609,10 +3639,10 @@ mod tests {
     fn test_simulation_of_terminal_false() {
         let scene = TestScenario::new("util");
 
-        let out = scene.ccmd("env").arg("sh").arg("is_atty.sh").succeeds();
+        let out = scene.ccmd("env").arg("sh").arg("is_a_tty.sh").succeeds();
         std::assert_eq!(
             String::from_utf8_lossy(out.stdout()),
-            "stdin is not atty\nstdout is not atty\nstderr is not atty\n"
+            "stdin is not a tty\nstdout is not a tty\nstderr is not a tty\n"
         );
         std::assert_eq!(
             String::from_utf8_lossy(out.stderr()),
@@ -3629,12 +3659,93 @@ mod tests {
         let out = scene
             .ccmd("env")
             .arg("sh")
-            .arg("is_atty.sh")
+            .arg("is_a_tty.sh")
             .terminal_simulation(true)
             .succeeds();
         std::assert_eq!(
             String::from_utf8_lossy(out.stdout()),
-            "stdin is atty\r\nstdout is atty\r\nstderr is atty\r\nterminal size: 30 80\r\n"
+            "stdin is a tty\r\nterminal size: 30 80\r\nstdout is a tty\r\nstderr is a tty\r\n"
+        );
+        std::assert_eq!(
+            String::from_utf8_lossy(out.stderr()),
+            "This is an error message.\r\n"
+        );
+    }
+
+    #[cfg(unix)]
+    #[cfg(feature = "env")]
+    #[test]
+    fn test_simulation_of_terminal_for_stdin_only() {
+        let scene = TestScenario::new("util");
+
+        let out = scene
+            .ccmd("env")
+            .arg("sh")
+            .arg("is_a_tty.sh")
+            .terminal_sim_stdio(TerminalSimulation {
+                stdin: true,
+                stdout: false,
+                stderr: false,
+                ..Default::default()
+            })
+            .succeeds();
+        std::assert_eq!(
+            String::from_utf8_lossy(out.stdout()),
+            "stdin is a tty\nterminal size: 30 80\nstdout is not a tty\nstderr is not a tty\n"
+        );
+        std::assert_eq!(
+            String::from_utf8_lossy(out.stderr()),
+            "This is an error message.\n"
+        );
+    }
+
+    #[cfg(unix)]
+    #[cfg(feature = "env")]
+    #[test]
+    fn test_simulation_of_terminal_for_stdout_only() {
+        let scene = TestScenario::new("util");
+
+        let out = scene
+            .ccmd("env")
+            .arg("sh")
+            .arg("is_a_tty.sh")
+            .terminal_sim_stdio(TerminalSimulation {
+                stdin: false,
+                stdout: true,
+                stderr: false,
+                ..Default::default()
+            })
+            .succeeds();
+        std::assert_eq!(
+            String::from_utf8_lossy(out.stdout()),
+            "stdin is not a tty\r\nstdout is a tty\r\nstderr is not a tty\r\n"
+        );
+        std::assert_eq!(
+            String::from_utf8_lossy(out.stderr()),
+            "This is an error message.\n"
+        );
+    }
+
+    #[cfg(unix)]
+    #[cfg(feature = "env")]
+    #[test]
+    fn test_simulation_of_terminal_for_stderr_only() {
+        let scene = TestScenario::new("util");
+
+        let out = scene
+            .ccmd("env")
+            .arg("sh")
+            .arg("is_a_tty.sh")
+            .terminal_sim_stdio(TerminalSimulation {
+                stdin: false,
+                stdout: false,
+                stderr: true,
+                ..Default::default()
+            })
+            .succeeds();
+        std::assert_eq!(
+            String::from_utf8_lossy(out.stdout()),
+            "stdin is not a tty\nstdout is not a tty\nstderr is a tty\n"
         );
         std::assert_eq!(
             String::from_utf8_lossy(out.stderr()),
@@ -3651,17 +3762,22 @@ mod tests {
         let out = scene
             .ccmd("env")
             .arg("sh")
-            .arg("is_atty.sh")
+            .arg("is_a_tty.sh")
-            .terminal_size(libc::winsize {
+            .terminal_sim_stdio(TerminalSimulation {
-                ws_col: 40,
+                size: Some(libc::winsize {
-                ws_row: 10,
+                    ws_col: 40,
-                ws_xpixel: 40 * 8,
+                    ws_row: 10,
-                ws_ypixel: 10 * 10,
+                    ws_xpixel: 40 * 8,
+                    ws_ypixel: 10 * 10,
+                }),
+                stdout: true,
+                stdin: true,
+                stderr: true,
             })
             .succeeds();
         std::assert_eq!(
             String::from_utf8_lossy(out.stdout()),
-            "stdin is atty\r\nstdout is atty\r\nstderr is atty\r\nterminal size: 10 40\r\n"
+            "stdin is a tty\r\nterminal size: 10 40\r\nstdout is a tty\r\nstderr is a tty\r\n"
         );
         std::assert_eq!(
             String::from_utf8_lossy(out.stderr()),

tests/fixtures/nohup/is_a_tty.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+if [ -t 0 ] ; then
+    echo "stdin is a tty"
+else
+    echo "stdin is not a tty"
+fi
+
+if [ -t 1 ] ; then
+    echo "stdout is a tty"
+else
+    echo "stdout is not a tty"
+fi
+
+if [ -t 2 ] ; then
+    echo "stderr is a tty"
+else
+    echo "stderr is not a tty"
+fi
+
+true

tests/fixtures/nohup/is_atty.sh

@@ -1,21 +0,0 @@
-#!/bin/bash
-
-if [ -t 0 ] ; then
-    echo "stdin is atty"
-else
-    echo "stdin is not atty"
-fi
-
-if [ -t 1 ] ; then
-    echo "stdout is atty"
-else
-    echo "stdout is not atty"
-fi
-
-if [ -t 2 ] ; then
-    echo "stderr is atty"
-else
-    echo "stderr is not atty"
-fi
-
-true

tests/fixtures/util/is_a_tty.sh

@@ -1,22 +1,22 @@
 #!/bin/bash
 
 if [ -t 0 ] ; then
-    echo "stdin is atty"
+    echo "stdin is a tty"
+    echo "terminal size: $(stty size)"
 else
-    echo "stdin is not atty"
+    echo "stdin is not a tty"
 fi
 
 if [ -t 1 ] ; then
-    echo "stdout is atty"
+    echo "stdout is a tty"
 else
-    echo "stdout is not atty"
+    echo "stdout is not a tty"
 fi
 
 if [ -t 2 ] ; then
-    echo "stderr is atty"
+    echo "stderr is a tty"
-    echo "terminal size: $(stty size)"
 else
-    echo "stderr is not atty"
+    echo "stderr is not a tty"
 fi
 
 >&2 echo "This is an error message."