Address issues raised in review

- serial port name comparison is now case-insensitive
- added docstrings which were missing for some subcommands
- espflash now displays help and exits if no arguments provided

Author: jessebraham

cargo-espflash/src/main.rs

@@ -53,7 +53,9 @@ struct EspFlashOpts {
 
 #[derive(Parser)]
 pub enum SubCommand {
+    /// Display information about the connected board and exit without flashing
     BoardInfo(ConnectOpts),
+    /// Save the image to disk instead of flashing to device
     SaveImage(SaveImageOpts),
 }
 
@@ -82,7 +84,6 @@ pub struct BuildOpts {
     pub unstable: Option<Vec<String>>,
 }
 
-/// Save the image to disk instead of flashing to device
 #[derive(Parser)]
 pub struct SaveImageOpts {
     #[clap(flatten)]

espflash/src/cli/serial.rs

@@ -64,7 +64,7 @@ pub fn get_serial_port_info(
 fn find_serial_port(ports: &[SerialPortInfo], name: String) -> Option<SerialPortInfo> {
     ports
         .iter()
-        .find(|port| port.port_name == name)
+        .find(|port| port.port_name.to_lowercase() == name.to_lowercase())
         .map(|port| port.to_owned())
 }
 

espflash/src/main.rs

@@ -28,11 +28,12 @@ struct Opts {
 
 #[derive(Parser)]
 pub enum SubCommand {
+    /// Display information about the connected board and exit without flashing
     BoardInfo(ConnectOpts),
+    /// Save the image to disk instead of flashing to device
     SaveImage(SaveImageOpts),
 }
 
-/// Save the image to disk instead of flashing to device
 #[derive(Parser)]
 pub struct SaveImageOpts {
     /// Image format to flash
@@ -52,8 +53,15 @@ fn main() -> Result<()> {
     let mut opts = Opts::parse();
     let config = Config::load()?;
 
-    // If only a single argument is passed, it's always going to be the ELF file. In
-    // the case that the serial port was not provided as a command-line argument,
+    // If neither the IMAGE nor SERIAL arguments have been provided, print the help
+    // message and exit.
+    if opts.image.is_none() && opts.connect_opts.serial.is_none() {
+        Opts::into_app().print_help().ok();
+        return Ok(());
+    }
+
+    // If only a single argument is passed, it *should* always be the ELF file.
+    // In the case that the serial port was not provided as a command-line argument,
     // we will either load the value specified in the configuration file or do port
     // auto-detection instead.
     if opts.image.is_none() && opts.connect_opts.serial.is_some() {