From b8308147042b4428273a83206a10546a502d28b3 Mon Sep 17 00:00:00 2001
From: f01d-zero <dev@itsscb.de>
Date: Mon, 10 Aug 2026 11:07:03 +0200
Subject: [PATCH] feat: add intro1 exercise

- compile gate: main lacks tail expression until TODO uncommented
- drop .gitkeep files; rustlings dev check forbids extra files
- in-loop TTY check lets solution exit clean under piped stdout
---
 Cargo.toml                   |  5 ++++-
 exercises/.gitkeep           |  1 -
 exercises/00_intro/intro1.rs | 36 ++++++++++++++++++++++++++++++++++++
 info.toml                    |  7 +++++--
 solutions/.gitkeep           |  1 -
 solutions/00_intro/intro1.rs | 33 +++++++++++++++++++++++++++++++++
 6 files changed, 78 insertions(+), 5 deletions(-)
 delete mode 100644 exercises/.gitkeep
 create mode 100644 exercises/00_intro/intro1.rs
 delete mode 100644 solutions/.gitkeep
 create mode 100644 solutions/00_intro/intro1.rs

diff --git a/Cargo.toml b/Cargo.toml
index ddb7887..cf174e6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,9 @@
 # Don't edit the `bin` list manually. Run `rustlings dev update` after changing
 # exercises or solutions.
-bin = []
+bin = [
+  { name = "intro1", path = "exercises/00_intro/intro1.rs" },
+  { name = "intro1_sol", path = "solutions/00_intro/intro1.rs" },
+]
 
 [package]
 name = "ratlings"
diff --git a/exercises/.gitkeep b/exercises/.gitkeep
deleted file mode 100644
index 8b13789..0000000
--- a/exercises/.gitkeep
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/exercises/00_intro/intro1.rs b/exercises/00_intro/intro1.rs
new file mode 100644
index 0000000..b8c5581
--- /dev/null
+++ b/exercises/00_intro/intro1.rs
@@ -0,0 +1,36 @@
+use ratatui::{DefaultTerminal, Frame};
+use std::io::IsTerminal;
+
+// Do not modify this line
+fn main() -> std::io::Result<()> {
+    // TODO: run the TUI app.
+    // ratatui::run(app)
+    todo!("run the TUI app.")
+}
+
+fn app(terminal: &mut DefaultTerminal) -> std::io::Result<()> {
+    loop {
+        terminal.draw(render)?;
+        if !std::io::stdout().is_terminal() || ratatui::crossterm::event::read()?.is_key_press() {
+            break Ok(());
+        }
+    }
+}
+
+fn render(frame: &mut Frame) {
+    frame.render_widget("hello world", frame.area());
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ratatui::{Terminal, backend::TestBackend};
+
+    #[test]
+    fn renders_hello_world() {
+        let mut terminal =
+            Terminal::new(TestBackend::new(15, 1)).expect("test backend initialization");
+        terminal.draw(render).expect("render frame");
+        terminal.backend().assert_buffer_lines(["hello world    "]);
+    }
+}
diff --git a/info.toml b/info.toml
index 5fdea47..f18a9ad 100644
--- a/info.toml
+++ b/info.toml
@@ -11,8 +11,6 @@ final_message = """
 You finished Ratlings! 🎉
 """
 
-exercises = []
-
 # Add exercise metadata here. See CONTRIBUTING.md and the Rustlings community
 # exercises guide: https://rustlings.rust-lang.org/community-exercises/
 #
@@ -20,3 +18,8 @@ exercises = []
 # name = "example"
 # dir = "section"
 # hint = "A helpful hint."
+
+[[exercises]]
+name = "intro1"
+dir = "00_intro"
+hint = "Uncomment the line below the TODO-comment."
diff --git a/solutions/.gitkeep b/solutions/.gitkeep
deleted file mode 100644
index 8b13789..0000000
--- a/solutions/.gitkeep
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/solutions/00_intro/intro1.rs b/solutions/00_intro/intro1.rs
new file mode 100644
index 0000000..e45486d
--- /dev/null
+++ b/solutions/00_intro/intro1.rs
@@ -0,0 +1,33 @@
+use ratatui::{DefaultTerminal, Frame};
+use std::io::IsTerminal;
+
+fn main() -> std::io::Result<()> {
+    ratatui::run(app)
+}
+
+fn app(terminal: &mut DefaultTerminal) -> std::io::Result<()> {
+    loop {
+        terminal.draw(render)?;
+        if !std::io::stdout().is_terminal() || ratatui::crossterm::event::read()?.is_key_press() {
+            break Ok(());
+        }
+    }
+}
+
+fn render(frame: &mut Frame) {
+    frame.render_widget("hello world", frame.area());
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use ratatui::{Terminal, backend::TestBackend};
+
+    #[test]
+    fn renders_hello_world() {
+        let mut terminal =
+            Terminal::new(TestBackend::new(15, 1)).expect("test backend initialization");
+        terminal.draw(render).expect("render frame");
+        terminal.backend().assert_buffer_lines(["hello world    "]);
+    }
+}