Accept a bare integer as seconds for watchpr --interval

- add agent.ParseDurationFlag: bare integer means seconds, duration strings still parse
- take --interval as a string and parse it in the command
- reject unparseable and non-positive values with an error naming the flag

cmd/watchpr/main.go

@@ -7,6 +7,7 @@
 //	watchpr owner/repo#12 owner/repo:15
 //	watchpr --once --json owner/repo#12
 //	watchpr --interval 30s owner/repo#12
+//	watchpr --interval 30 owner/repo#12
 package main
 
 import (
@@ -34,7 +35,7 @@ func main() {
 // tests can invoke Execute and assert the exit behaviour without spawning a
 // process.
 func newRootCmd() *cobra.Command {
-	var interval time.Duration
+	var intervalFlag string
 	var once, jsonMode bool
 
 	root := &cobra.Command{
@@ -50,6 +51,10 @@ func newRootCmd() *cobra.Command {
 			if len(args) == 0 {
 				return fmt.Errorf("no PR references given (e.g. owner/repo#12)")
 			}
+			interval, err := agent.ParseDurationFlag("interval", intervalFlag)
+			if err != nil {
+				return err
+			}
 			refs := make([]agent.PRRef, 0, len(args))
 			for _, a := range args {
 				ref, err := agent.ParsePRRef(a)
@@ -68,7 +73,7 @@ func newRootCmd() *cobra.Command {
 	root.SetVersionTemplate("{{.Version}}\n")
 
 	f := root.Flags()
-	f.DurationVar(&interval, "interval", 60*time.Second, "Polling interval")
+	f.StringVar(&intervalFlag, "interval", "60s", "Polling interval: a duration (30s, 2m, 1h30m) or a bare number of seconds")
 	f.BoolVar(&once, "once", false, "Check once, print current state, and exit")
 	f.BoolVar(&jsonMode, "json", false, "Emit JSON")
 

cmd/watchpr/main_test.go

@@ -4,6 +4,7 @@ import (
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 )
 
@@ -70,3 +71,37 @@ func TestOnceRunsAnonymouslyWhenNoTokenIsAvailable(t *testing.T) {
 		t.Errorf("sent %d Authorization headers, want none", authHeaders)
 	}
 }
+
+// A bare integer interval means seconds and must survive flag parsing: the
+// command should fail on the missing PR reference, not on the flag value.
+func TestExecuteBareIntervalIsSeconds(t *testing.T) {
+	cmd := newRootCmd()
+	cmd.SetArgs([]string{"--interval", "15"})
+	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
+	err := cmd.Execute()
+	if err == nil {
+		t.Fatal("Execute() = nil, want the no-references error")
+	}
+	if !strings.Contains(err.Error(), "no PR references given") {
+		t.Fatalf("Execute() error = %v, want the no-references error", err)
+	}
+}
+
+// An unparseable interval is rejected before any Vault/Gitea call, with an
+// error naming the flag and showing valid forms.
+func TestExecuteBadIntervalErrors(t *testing.T) {
+	cmd := newRootCmd()
+	cmd.SetArgs([]string{"--interval", "soon", "unkin/repo#1"})
+	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
+	err := cmd.Execute()
+	if err == nil {
+		t.Fatal("Execute() = nil, want error for an unparseable --interval")
+	}
+	for _, want := range []string{"--interval", "30s"} {
+		if !strings.Contains(err.Error(), want) {
+			t.Errorf("Execute() error %q does not mention %q", err, want)
+		}
+	}
+}