docs: rework documentation, prepare pre-release

Signed-off-by: Henry <mail@henrygressmann.de>

4 files changed, 15 insertions, 9 deletions

diff --git a/crates/cli/Cargo.toml b/crates/cli/Cargo.toml
index caf541b..8472afb 100644
--- a/crates/cli/Cargo.toml
+++ b/crates/cli/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name="tinywasm-cli"
 version.workspace=true
-description="TinyWasm CLI"
+description="Command-line interface for TinyWasm"
 edition.workspace=true
 license.workspace=true
 authors.workspace=true
@@ -9,6 +9,7 @@ repository.workspace=true
 rust-version.workspace=true
 keywords.workspace=true
 categories=["wasm"]
+readme="README.md"
 
 [[bin]]
 name="tinywasm-cli"
diff --git a/crates/cli/README.md b/crates/cli/README.md
index 70b2cff..aa4d0c8 100644
--- a/crates/cli/README.md
+++ b/crates/cli/README.md
@@ -8,4 +8,6 @@ It is recommended to use the library directly instead of the CLI.
 ```bash
 $ cargo install tinywasm-cli
 $ tinywasm-cli --help
+$ tinywasm-cli run ./module.wasm
+$ tinywasm-cli run ./module.wasm -f add -a i32:1 -a i32:2
 ```
diff --git a/crates/cli/src/args.rs b/crates/cli/src/args.rs
index 1fec2d5..0333c92 100644
--- a/crates/cli/src/args.rs
+++ b/crates/cli/src/args.rs
@@ -17,8 +17,11 @@ impl From<WasmArg> for WasmValue {
 impl FromStr for WasmArg {
     type Err = String;
     fn from_str(s: &str) -> std::prelude::v1::Result<Self, Self::Err> {
-        let [ty, val]: [&str; 2] =
-            s.split(':').collect::<Vec<_>>().try_into().map_err(|e| format!("invalid arguments: {e:?}"))?;
+        let [ty, val]: [&str; 2] = s
+            .split(':')
+            .collect::<Vec<_>>()
+            .try_into()
+            .map_err(|_e| "invalid argument format; expected type:value".to_string())?;
 
         let arg: WasmValue = match ty {
             "i32" => val.parse::<i32>().map_err(|e| format!("invalid argument value for i32: {e:?}"))?.into(),
@@ -26,7 +29,7 @@ impl FromStr for WasmArg {
             "f32" => val.parse::<f32>().map_err(|e| format!("invalid argument value for f32: {e:?}"))?.into(),
             "f64" => val.parse::<f64>().map_err(|e| format!("invalid argument value for f64: {e:?}"))?.into(),
             "v128" => val.parse::<i128>().map_err(|e| format!("invalid argument value for v128: {e:?}"))?.into(),
-            t => return Err(format!("Invalid arg type: {t}")),
+            t => return Err(format!("invalid arg type `{t}`; expected one of i32, i64, f32, f64, v128")),
         };
 
         Ok(WasmArg(arg))
diff --git a/crates/cli/src/bin.rs b/crates/cli/src/bin.rs
index 9b283c3..7e32fed 100644
--- a/crates/cli/src/bin.rs
+++ b/crates/cli/src/bin.rs
@@ -19,7 +19,7 @@ struct TinyWasmCli {
     #[argh(subcommand)]
     nested: TinyWasmSubcommand,
 
-    /// log level
+    /// log level: trace, debug, info, warn, or error
     #[argh(option, short = 'l', default = "\"info\".to_string()")]
     log_level: String,
 }
@@ -53,15 +53,15 @@ struct Run {
     #[argh(positional)]
     wasm_file: String,
 
-    /// function to run
+    /// exported function to run; omit to only instantiate and run start
     #[argh(option, short = 'f')]
     func: Option<String>,
 
-    /// arguments to pass to the wasm file
+    /// arguments passed to the function in type:value form
     #[argh(option, short = 'a')]
     args: Vec<WasmArg>,
 
-    /// engine to use
+    /// engine to use (currently only `main`)
     #[argh(option, short = 'e', default = "Engine::Main")]
     engine: Engine,
 }
@@ -74,7 +74,7 @@ fn main() -> Result<()> {
         "warn" => log::LevelFilter::Warn,
         "error" => log::LevelFilter::Error,
         "info" => log::LevelFilter::Info,
-        _ => log::LevelFilter::Info,
+        other => return Err(eyre::eyre!("invalid log level `{other}`; expected trace, debug, info, warn, or error")),
     };
 
     pretty_env_logger::formatted_builder().filter_level(level).init();