Add an example for interact session with callbacks

Co-authored-by: Gary Boone <https://github.com/GaryBoone/>
Signed-off-by: Maxim Zhiburt <[email protected]>

.gitignore

@@ -8,3 +8,7 @@ Cargo.lock
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
+
+# Python cache
+**/*.pyc
+__pycache__

examples/interact_with_callbacks.rs

@@ -0,0 +1,31 @@
+#[cfg(not(feature = "async"))]
+fn main() {
+    let mut session =
+        expectrl::spawn("python ./tests/source/ansi.py").expect("Can't spawn a session");
+
+    let opts = expectrl::interact::InteractOptions::terminal()
+        .unwrap()
+        .on_input("HelloWorld!", |_| {
+            print!("You typed a magic word...\r\n");
+            Ok(())
+        });
+
+    opts.interact(&mut session).unwrap();
+}
+
+#[cfg(feature = "async")]
+fn main() {
+    let mut session =
+        expectrl::spawn("python ./tests/source/ansi.py").expect("Can't spawn a session");
+
+    let opts = expectrl::interact::InteractOptions::terminal()
+        .unwrap()
+        .on_input("HelloWorld!", |session| {
+            print!("You typed a magic word...\r\n");
+            Ok(())
+        });
+
+    futures_lite::future::block_on(async {
+        opts.interact(&mut session).await.unwrap();
+    });
+}

tests/source/ansi.py

@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+
+# The file was developed by https://github.com/GaryBoone/
+
+from colors import colorize, Color
+import sys
+import time
+import getpass
+
+NUM_LINES = 5
+SAME_LINE_ESC = "\033[F"
+
+def main():
+    """Demonstrate several kinds of terminal outputs.
+
+    Examples including ANSI codes, "\r" without "\n", writing to stdin, no-echo
+    inputs.
+    """
+
+    # Show a color.
+    print("status: ", colorize("good", Color.GREEN))
+
+    # Show same-line output via "\r".
+    for i in range(NUM_LINES):
+        sys.stdout.write(f"[{i+1}/{NUM_LINES}]: file{i}\r")
+        time.sleep(1)
+    print("\n")
+
+    # Show same-line output via an ANSI code.
+    for i in range(NUM_LINES):
+        print(f"{SAME_LINE_ESC}[{i+1}/{NUM_LINES}]: file{i}")
+        time.sleep(1)
+
+    # Handle prompts which don't repeat input to stdout.
+    print("Here is a test password prompt")
+    print(colorize("Do not enter a real password", Color.RED))
+    getpass.getpass()
+
+    # Handle simple input.
+    ans = input("Continue [y/n]:")
+    col = Color.GREEN if ans == "y" else Color.RED
+    print(f"You said: {colorize(ans, col)}")
+    if ans == "n" or ans == "":
+        sys.exit(0)
+
+    # Handle long-running process, like starting a server.
+    print("[Starting long running process...]")
+    print("[Ctrl-C to exit]")
+    while True:
+        print("status: ", colorize("good", Color.GREEN))
+        time.sleep(1)
+
+if __name__ == "__main__":
+    main()

tests/source/colors.py

@@ -0,0 +1,15 @@
+import enum
+
+class Color(enum.Enum):
+    RESET = "\33[0m"
+    RED = "\33[31m"
+    GREEN = "\33[32m"
+    YELLOW = "\33[33m"
+
+
+def colorize(text: str, color: Color) -> str:
+    """Wrap `text` in terminal color directives.
+
+    The return value will show up as the given color when printed in a terminal.
+    """
+    return f"{color.value}{text}{Color.RESET.value}"