Prepare CLI for move into mainline

packages/cli/src/logging.rs

@@ -0,0 +1,35 @@
+use fern::colors::{Color, ColoredLevelConfig};
+
+pub fn set_up_logging() {
+    // configure colors for the whole line
+    let colors_line = ColoredLevelConfig::new()
+        .error(Color::Red)
+        .warn(Color::Yellow)
+        // we actually don't need to specify the color for debug and info, they are white by default
+        .info(Color::White)
+        .debug(Color::White)
+        // depending on the terminals color scheme, this is the same as the background color
+        .trace(Color::BrightBlack);
+
+    // configure colors for the name of the level.
+    // since almost all of them are the same as the color for the whole line, we
+    // just clone `colors_line` and overwrite our changes
+    let colors_level = colors_line.info(Color::Green);
+    // here we set up our fern Dispatch
+    fern::Dispatch::new()
+        .format(move |out, message, record| {
+            out.finish(format_args!(
+                "{color_line}[{level}{color_line}] {message}\x1B[0m",
+                color_line = format_args!(
+                    "\x1B[{}m",
+                    colors_line.get_color(&record.level()).to_fg_str()
+                ),
+                level = colors_level.color(record.level()),
+                message = message,
+            ));
+        })
+        .level(log::LevelFilter::Info)
+        .chain(std::io::stdout())
+        .apply()
+        .unwrap();
+}