feat: add canister query command

Author: Hans Larsen

dfx/src/commands/canister/mod.rs

@@ -5,14 +5,16 @@ use clap::{App, ArgMatches, SubCommand};
 
 mod call;
 mod install;
+mod query;
 
 fn builtins<T>() -> Vec<CliCommand<T>>
 where
     T: ClientEnv + ProjectConfigEnv,
 {
     vec![
-        CliCommand::new(install::construct(), install::exec),
         CliCommand::new(call::construct(), call::exec),
+        CliCommand::new(install::construct(), install::exec),
+        CliCommand::new(query::construct(), query::exec),
     ]
 }
 

dfx/src/commands/canister/query.rs

@@ -0,0 +1,76 @@
+use crate::lib::api_client::{query, Blob, CanisterQueryCall, QueryResponseReply, ReadResponse};
+use crate::lib::env::ClientEnv;
+use crate::lib::error::{DfxError, DfxResult};
+use clap::{App, Arg, ArgMatches, SubCommand};
+use tokio::runtime::Runtime;
+
+fn is_number(v: String) -> Result<(), String> {
+    v.parse::<u64>()
+        .map_err(|_| String::from("The value must be a number."))
+        .map(|_| ())
+}
+
+pub fn construct() -> App<'static, 'static> {
+    SubCommand::with_name("query")
+        .about("Query a canister.")
+        .arg(
+            Arg::with_name("canister")
+                .takes_value(true)
+                .help("The canister ID (a number) to query.")
+                .required(true)
+                .validator(is_number),
+        )
+        .arg(
+            Arg::with_name("method_name")
+                .help("The query method name file to use.")
+                .required(true),
+        )
+        .arg(
+            Arg::with_name("arguments")
+                .help("Arguments to pass to the method.")
+                .takes_value(true)
+                .multiple(true),
+        )
+}
+
+pub fn exec<T>(env: &T, args: &ArgMatches<'_>) -> DfxResult
+where
+    T: ClientEnv,
+{
+    // Read the config.
+    let canister_id = args.value_of("canister").unwrap().parse::<u64>()?;
+    let method_name = args.value_of("method_name").unwrap();
+    let arguments: Option<Vec<&str>> = args.values_of("arguments").map(|args| args.collect());
+
+    let client = env.get_client();
+    let install = query(
+        client,
+        CanisterQueryCall {
+            canister_id,
+            method_name: method_name.to_owned(),
+            arg: arguments
+                .map(|args| Blob(Vec::from(args[0])))
+                .unwrap_or_else(|| Blob(vec![])),
+        },
+    );
+
+    let mut runtime = Runtime::new().expect("Unable to create a runtime");
+    match runtime.block_on(install) {
+        Ok(ReadResponse::Pending) => {
+            println!("Pending");
+            Ok(())
+        }
+        Ok(ReadResponse::Replied {
+            reply: QueryResponseReply { arg: Blob(blob) },
+        }) => {
+            println!("{}", String::from_utf8_lossy(&blob));
+            Ok(())
+        }
+        Ok(ReadResponse::Rejected {
+            reject_code,
+            reject_message,
+        }) => Err(DfxError::ClientError(reject_code, reject_message)),
+        Ok(ReadResponse::Unknown) => Err(DfxError::Unknown("Unknown response".to_owned())),
+        Err(x) => Err(DfxError::from(x)),
+    }
+}