chore: improve help text for forge snapshot (#1304)

cli/src/cmd/forge/snapshot.rs

@@ -33,32 +33,39 @@ pub static RE_BASIC_SNAPSHOT_ENTRY: Lazy<Regex> = Lazy::new(|| {
 #[derive(Debug, Clone, Parser)]
 pub struct SnapshotArgs {
     /// All test arguments are supported
-    #[clap(flatten)]
+    #[clap(flatten, next_help_heading = "TEST OPTIONS")]
     pub(crate) test: test::TestArgs,
 
     /// Additional configs for test results
     #[clap(flatten)]
     config: SnapshotConfig,
 
+    /// Output a diff against a pre-existing snapshot.
+    ///
+    /// By default the comparison is done with .gas-snapshot.
     #[clap(
-        help = "Compare against a snapshot and display changes from the snapshot. Takes an optional snapshot file, [default: .gas-snapshot]",
         conflicts_with = "snap",
         long,
         value_hint = ValueHint::FilePath,
         value_name = "SNAPSHOT_FILE",
     )]
     diff: Option<Option<PathBuf>>,
 
+    /// Compare against a pre-existing snapshot, exiting with code 1 if they do not match.
+    ///
+    /// Outputs a diff if the snapshots do not match.
+    ///
+    /// By default the comparison is done with .gas-snapshot.
     #[clap(
-        help = "Run snapshot in 'check' mode and compares against an existing snapshot file, [default: .gas-snapshot]. Exits with 0 if snapshots match. Exits with 1 and prints a diff otherwise",
         conflicts_with = "diff",
         long,
         value_hint = ValueHint::FilePath,
         value_name = "SNAPSHOT_FILE",
     )]
     check: Option<Option<PathBuf>>,
 
-    #[clap(help = "How to format the output.", long)]
+    // Hidden because there is only one option
+    #[clap(help = "How to format the output.", long, hide(true))]
     format: Option<Format>,
 
     #[clap(
@@ -139,9 +146,9 @@ impl FromStr for Format {
 /// Additional filters that can be applied on the test results
 #[derive(Debug, Clone, Parser, Default)]
 struct SnapshotConfig {
-    #[clap(help = "sort results by ascending gas used.", long)]
+    #[clap(help = "Sort results by gas used (ascending).", long)]
     asc: bool,
-    #[clap(help = "sort results by descending gas used.", conflicts_with = "asc", long)]
+    #[clap(help = "Sort results by gas used (descending).", conflicts_with = "asc", long)]
     desc: bool,
     #[clap(help = "Only include tests that used more gas that the given amount.", long)]
     min: Option<u64>,