From 9310b54d439d4a1a8d4d337987aa63884df0af76 Mon Sep 17 00:00:00 2001
From: Paul Buetow <paul@buetow.org>
Date: Wed, 20 May 2026 11:38:19 +0300
Subject: feat: add syscall aggregate sampling infrastructure (task 17)

---
 internal/flags/sampling_test.go | 78 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 internal/flags/sampling_test.go

(limited to 'internal/flags/sampling_test.go')

diff --git a/internal/flags/sampling_test.go b/internal/flags/sampling_test.go
new file mode 100644
index 0000000..0966c0f
--- /dev/null
+++ b/internal/flags/sampling_test.go
@@ -0,0 +1,78 @@
+package flags
+
+import (
+	"strings"
+	"testing"
+
+	"ior/internal/types"
+)
+
+func TestParseSamplingRates(t *testing.T) {
+	cfg, err := parseForTest(t,
+		"-syscall-sampling-families", "Time=100,misc=0",
+		"-syscall-sampling-syscalls", "futex=0,clock_gettime=7",
+	)
+	if err != nil {
+		t.Fatalf("parse returned error: %v", err)
+	}
+
+	if got := cfg.SyscallFamilySamplingRates[types.FamilyTime]; got != 100 {
+		t.Fatalf("Time family rate = %d, want 100", got)
+	}
+	if got := cfg.SyscallFamilySamplingRates[types.FamilyMisc]; got != 0 {
+		t.Fatalf("Misc family rate = %d, want 0", got)
+	}
+	if got := cfg.SyscallSamplingRates["futex"]; got != 0 {
+		t.Fatalf("futex rate = %d, want 0", got)
+	}
+	if got := cfg.SyscallSamplingRates["clock_gettime"]; got != 7 {
+		t.Fatalf("clock_gettime rate = %d, want 7", got)
+	}
+}
+
+func TestParseSamplingFamilyRejectsUnknown(t *testing.T) {
+	_, err := parseForTest(t, "-syscall-sampling-families", "Nope=4")
+	if err == nil {
+		t.Fatal("expected parse error")
+	}
+	if !strings.Contains(err.Error(), "invalid syscall family") {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func TestParseSamplingSyscallRejectsMalformedEntry(t *testing.T) {
+	_, err := parseForTest(t, "-syscall-sampling-syscalls", "futex")
+	if err == nil {
+		t.Fatal("expected parse error")
+	}
+	if !strings.Contains(err.Error(), "expected name=rate") {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func TestParseSamplingSyscallRejectsUnknownName(t *testing.T) {
+	_, err := parseForTest(t, "-syscall-sampling-syscalls", "not_a_syscall=2")
+	if err == nil {
+		t.Fatal("expected parse error")
+	}
+	if !strings.Contains(err.Error(), "invalid syscall in sampling map") {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func TestCloneDeepCopiesSamplingMaps(t *testing.T) {
+	cfg := NewFlags()
+	cfg.SyscallFamilySamplingRates[types.FamilyTime] = 5
+	cfg.SyscallSamplingRates["futex"] = 9
+
+	cloned := cfg.Clone()
+	cloned.SyscallFamilySamplingRates[types.FamilyTime] = 100
+	cloned.SyscallSamplingRates["futex"] = 1
+
+	if got := cfg.SyscallFamilySamplingRates[types.FamilyTime]; got != 5 {
+		t.Fatalf("original family rate mutated: got %d, want 5", got)
+	}
+	if got := cfg.SyscallSamplingRates["futex"]; got != 9 {
+		t.Fatalf("original syscall rate mutated: got %d, want 9", got)
+	}
+}
-- 
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