Fix panic on --runs 0 (#923)

* fix: reject --runs/--max-runs 0, clamp --min-runs to 1

* Validate positive run counts with clap

---------

Co-authored-by: VXNCXNX <VXNCXNX@users.noreply.github.com>
Co-authored-by: David Peter <mail@david-peter.de>

src/cli.rs

@@ -41,6 +41,7 @@ fn build_command() -> Command {
                 .short('w')
                 .value_name("NUM")
                 .action(ArgAction::Set)
+                .value_parser(clap::value_parser!(u64))
                 .help(
                     "Perform NUM warmup runs before the actual benchmark. This can be used \
                      to fill (disk) caches for I/O-heavy programs.",
@@ -52,6 +53,7 @@ fn build_command() -> Command {
                 .short('m')
                 .action(ArgAction::Set)
                 .value_name("NUM")
+                .value_parser(clap::value_parser!(u64).range(1..))
                 .help("Perform at least NUM runs for each command (default: 10)."),
         )
         .arg(
@@ -60,6 +62,7 @@ fn build_command() -> Command {
                 .short('M')
                 .action(ArgAction::Set)
                 .value_name("NUM")
+                .value_parser(clap::value_parser!(u64).range(1..))
                 .help("Perform at most NUM runs for each command. By default, there is no limit."),
         )
         .arg(
@@ -69,6 +72,7 @@ fn build_command() -> Command {
                 .short('r')
                 .action(ArgAction::Set)
                 .value_name("NUM")
+                .value_parser(clap::value_parser!(u64).range(1..))
                 .help("Perform exactly NUM runs for each command. If this option is not specified, \
                        hyperfine automatically determines the number of runs."),
         )

src/options.rs

@@ -275,22 +275,15 @@ impl Default for Options {
 impl Options {
     pub fn from_cli_arguments<'a>(matches: &ArgMatches) -> Result<Self, OptionsError<'a>> {
         let mut options = Self::default();
-        let param_to_u64 = |param| {
-            matches
-                .get_one::<String>(param)
-                .map(|n| {
-                    n.parse::<u64>()
-                        .map_err(|e| OptionsError::IntParsingError(param, e))
-                })
-                .transpose()
-        };
+        options.warmup_count = matches
+            .get_one::<u64>("warmup")
+            .copied()
+            .unwrap_or(options.warmup_count);
 
-        options.warmup_count = param_to_u64("warmup")?.unwrap_or(options.warmup_count);
+        let mut min_runs = matches.get_one::<u64>("min-runs").copied();
+        let mut max_runs = matches.get_one::<u64>("max-runs").copied();
 
-        let mut min_runs = param_to_u64("min-runs")?;
-        let mut max_runs = param_to_u64("max-runs")?;
-
-        if let Some(runs) = param_to_u64("runs")? {
+        if let Some(&runs) = matches.get_one::<u64>("runs") {
             min_runs = Some(runs);
             max_runs = Some(runs);
         }

tests/integration_tests.rs

@@ -74,6 +74,32 @@ fn exits_quietly_when_stdout_is_closed() {
     }
 }
 
+#[test]
+fn fails_with_zero_runs() {
+    for option in ["--runs", "--min-runs", "--max-runs"] {
+        hyperfine()
+            .arg(option)
+            .arg("0")
+            .arg("echo dummy benchmark")
+            .assert()
+            .code(2)
+            .stderr(predicate::str::contains(format!(
+                "invalid value '0' for '{option} <NUM>'"
+            )));
+    }
+}
+
+#[test]
+fn min_runs_of_one_still_performs_one_run() {
+    hyperfine_debug()
+        .arg("--min-runs=1")
+        .arg("--warmup=0")
+        .arg("sleep 4")
+        .assert()
+        .success()
+        .stdout(predicate::str::contains("Time (abs ≡)"));
+}
+
 #[test]
 fn can_run_commands_without_a_shell() {
     hyperfine()