From 3298a6adf10cd0f4807bbcd6ce93c39af336779f Mon Sep 17 00:00:00 2001
From: doug-q <141026920+doug-q@users.noreply.github.com>
Date: Wed, 29 May 2024 10:43:09 +0100
Subject: [PATCH] feat(cli): Add verbosity, return `Hugr` from `run`. (#1116)

---
 Cargo.toml          |  3 ++-
 hugr-cli/Cargo.toml |  3 ++-
 hugr-cli/src/lib.rs | 26 ++++++++++++++++++++------
 hugr/src/main.rs    |  6 ++++--
 hugr/tests/cli.rs   | 22 ++++++++++++++++++++--
 5 files changed, 48 insertions(+), 12 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 54fed82da..8330b6447 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -57,9 +57,10 @@ typetag = "0.2.7"
 urlencoding = "2.1.2"
 webbrowser = "1.0.0"
 clap = { version = "4.5.4"}
+clap-stdin = "0.4.0"
+clap-verbosity-flag = "2.2.0"
 assert_cmd = "2.0.14"
 assert_fs = "1.1.1"
-clap-stdin = "0.4.0"
 predicates = "3.1.0"
 
 [profile.dev.package]
diff --git a/hugr-cli/Cargo.toml b/hugr-cli/Cargo.toml
index 067a08a67..90f71e362 100644
--- a/hugr-cli/Cargo.toml
+++ b/hugr-cli/Cargo.toml
@@ -15,7 +15,8 @@ categories = ["compilers"]
 
 [dependencies]
 clap = {workspace = true, features = ["derive"]}
-clap-stdin = { workspace = true }
+clap-stdin.workspace = true
+clap-verbosity-flag.workspace = true
 hugr-core = { path = "../hugr-core", version = "0.0.0" }
 serde_json.workspace = true
 thiserror.workspace = true
diff --git a/hugr-cli/src/lib.rs b/hugr-cli/src/lib.rs
index 421a900fa..07982b589 100644
--- a/hugr-cli/src/lib.rs
+++ b/hugr-cli/src/lib.rs
@@ -1,13 +1,18 @@
 //! Standard command line tools, used by the hugr binary.
 
-pub use clap::Parser;
 use clap_stdin::FileOrStdin;
-use hugr_core::{extension::ExtensionRegistry, Hugr, HugrView};
+use clap_verbosity_flag::{InfoLevel, Verbosity};
 use thiserror::Error;
+/// We reexport some clap types that are used in the public API.
+pub use {clap::Parser, clap_verbosity_flag::Level};
+
+use hugr_core::{extension::ExtensionRegistry, Hugr, HugrView};
+
 /// Validate and visualise a HUGR file.
 #[derive(Parser, Debug)]
 #[clap(version = "1.0", long_about = None)]
 #[clap(about = "Validate a HUGR.")]
+#[group(id = "hugr")]
 pub struct CmdLineArgs {
     input: FileOrStdin,
     /// Visualise with mermaid.
@@ -16,6 +21,9 @@ pub struct CmdLineArgs {
     /// Skip validation.
     #[arg(short, long, help = "Skip validation.")]
     no_validate: bool,
+    /// Verbosity.
+    #[command(flatten)]
+    verbose: Verbosity<InfoLevel>,
     // TODO YAML extensions
 }
 
@@ -38,7 +46,7 @@ pub const VALID_PRINT: &str = "HUGR valid!";
 
 impl CmdLineArgs {
     /// Run the HUGR cli and validate against an extension registry.
-    pub fn run(&self, registry: &ExtensionRegistry) -> Result<(), CliError> {
+    pub fn run(&self, registry: &ExtensionRegistry) -> Result<Hugr, CliError> {
         let mut hugr: Hugr = serde_json::from_reader(self.input.into_reader()?)?;
         if self.mermaid {
             println!("{}", hugr.mermaid_string());
@@ -46,9 +54,15 @@ impl CmdLineArgs {
 
         if !self.no_validate {
             hugr.update_validate(registry)?;
-
-            println!("{}", VALID_PRINT);
+            if self.verbosity(Level::Info) {
+                eprintln!("{}", VALID_PRINT);
+            }
         }
-        Ok(())
+        Ok(hugr)
+    }
+
+    /// Test whether a `level` message should be output.
+    pub fn verbosity(&self, level: Level) -> bool {
+        self.verbose.log_level_filter() >= level
     }
 }
diff --git a/hugr/src/main.rs b/hugr/src/main.rs
index a1bf109f4..2febb3baf 100644
--- a/hugr/src/main.rs
+++ b/hugr/src/main.rs
@@ -9,7 +9,7 @@ use hugr::std_extensions::logic::EXTENSION as LOGICS_EXTENSION;
 
 use hugr::extension::{ExtensionRegistry, PRELUDE};
 
-use hugr_cli::{CmdLineArgs, Parser};
+use hugr_cli::{CmdLineArgs, Level, Parser};
 
 fn main() {
     let opts = CmdLineArgs::parse();
@@ -27,7 +27,9 @@ fn main() {
     .unwrap();
 
     if let Err(e) = opts.run(&reg) {
-        eprintln!("{}", e);
+        if opts.verbosity(Level::Error) {
+            eprintln!("{}", e);
+        }
         std::process::exit(1);
     }
 }
diff --git a/hugr/tests/cli.rs b/hugr/tests/cli.rs
index 99ced61a4..1df2199a8 100644
--- a/hugr/tests/cli.rs
+++ b/hugr/tests/cli.rs
@@ -48,7 +48,7 @@ fn test_doesnt_exist(mut cmd: Command) {
 #[rstest]
 fn test_validate(test_hugr_file: NamedTempFile, mut cmd: Command) {
     cmd.arg(test_hugr_file.path());
-    cmd.assert().success().stdout(contains(VALID_PRINT));
+    cmd.assert().success().stderr(contains(VALID_PRINT));
 }
 
 #[rstest]
@@ -56,7 +56,15 @@ fn test_stdin(test_hugr_string: String, mut cmd: Command) {
     cmd.write_stdin(test_hugr_string);
     cmd.arg("-");
 
-    cmd.assert().success().stdout(contains(VALID_PRINT));
+    cmd.assert().success().stderr(contains(VALID_PRINT));
+}
+
+#[rstest]
+fn test_stdin_silent(test_hugr_string: String, mut cmd: Command) {
+    cmd.args(["-", "-q"]);
+    cmd.write_stdin(test_hugr_string);
+
+    cmd.assert().success().stderr(contains(VALID_PRINT).not());
 }
 
 #[rstest]
@@ -91,3 +99,13 @@ fn test_bad_json(mut cmd: Command) {
         .failure()
         .stderr(contains("Error parsing input"));
 }
+
+#[rstest]
+fn test_bad_json_silent(mut cmd: Command) {
+    cmd.write_stdin(r#"{"foo": "bar"}"#);
+    cmd.args(["-", "-qqq"]);
+
+    cmd.assert()
+        .failure()
+        .stderr(contains("Error parsing input").not());
+}