Improve capabilities of ion schema subcommands

Cargo.toml

@@ -13,14 +13,16 @@ keywords = ["format", "parse", "encode"]
 
 [dependencies]
 anyhow = "1.0"
-clap = { version = "4.5.8", features = ["cargo", "env"] }
+clap = { version = "4.5.8", features = ["cargo", "env","wrap_help"] }
 colored = "2.0.0"
 digest = "0.9"
 sha2 = "0.9"
 sha3 = "0.9"
 flate2 = "1.0"
 infer = "0.15.0"
-ion-rs = { version = "1.0.0-rc.8", features = ["experimental", "experimental-ion-hash"] }
+# ion-rs version must be pinned because we are using experimental features
+# See https://github.com/amazon-ion/ion-cli/issues/155
+ion-rs = { version = "=1.0.0-rc.8", features = ["experimental", "experimental-ion-hash"] }
 tempfile = "3.2.0"
 ion-schema = "0.14.0"
 lowcharts = "0.5.8"

src/bin/ion/commands/schema/check.rs

@@ -0,0 +1,38 @@
+use crate::commands::schema::IonSchemaCommandInput;
+use crate::commands::IonCliCommand;
+use anyhow::Result;
+use clap::{Arg, ArgAction, ArgMatches, Command};
+
+pub struct CheckCommand;
+
+impl IonCliCommand for CheckCommand {
+    fn name(&self) -> &'static str {
+        "check"
+    }
+
+    fn about(&self) -> &'static str {
+        "Loads a schema and checks it for problems."
+    }
+
+    fn is_stable(&self) -> bool {
+        false
+    }
+
+    fn configure_args(&self, command: Command) -> Command {
+        command.args(IonSchemaCommandInput::schema_args()).arg(
+            Arg::new("show-debug")
+                .short('D')
+                .long("show-debug")
+                .action(ArgAction::SetTrue),
+        )
+    }
+
+    fn run(&self, _command_path: &mut Vec<String>, args: &ArgMatches) -> Result<()> {
+        let ion_schema_input = IonSchemaCommandInput::read_from_args(args)?;
+        let schema = ion_schema_input.get_schema();
+        if args.get_flag("show-debug") {
+            println!("Schema: {:#?}", schema);
+        }
+        Ok(())
+    }
+}