From ccc248f4971d3924c91f3cf4bb1f0c30d4571217 Mon Sep 17 00:00:00 2001
From: rcourtman <courtmanr@gmail.com>
Date: Sun, 30 Nov 2025 04:50:51 +0000
Subject: [PATCH] Add unit tests for sanitizeNodeLabel
 (pulse-sensor-proxy/metrics.go)

---
 cmd/pulse-sensor-proxy/metrics_test.go | 227 +++++++++++++++++++++++++
 1 file changed, 227 insertions(+)
 create mode 100644 cmd/pulse-sensor-proxy/metrics_test.go

diff --git a/cmd/pulse-sensor-proxy/metrics_test.go b/cmd/pulse-sensor-proxy/metrics_test.go
new file mode 100644
index 0000000..dee2e33
--- /dev/null
+++ b/cmd/pulse-sensor-proxy/metrics_test.go
@@ -0,0 +1,227 @@
+package main
+
+import "testing"
+
+func TestSanitizeNodeLabel(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		// Basic cases
+		{
+			name:  "simple hostname",
+			input: "node1",
+			want:  "node1",
+		},
+		{
+			name:  "hostname with hyphen",
+			input: "node-1",
+			want:  "node-1",
+		},
+		{
+			name:  "hostname with underscore",
+			input: "node_1",
+			want:  "node_1",
+		},
+		{
+			name:  "hostname with dot",
+			input: "node.local",
+			want:  "node.local",
+		},
+		{
+			name:  "fqdn",
+			input: "node1.example.com",
+			want:  "node1.example.com",
+		},
+
+		// Case conversion
+		{
+			name:  "uppercase converted to lowercase",
+			input: "Node1",
+			want:  "node1",
+		},
+		{
+			name:  "mixed case",
+			input: "MyNode-Server",
+			want:  "mynode-server",
+		},
+		{
+			name:  "all uppercase",
+			input: "PRODSERVER01",
+			want:  "prodserver01",
+		},
+
+		// Special character handling
+		{
+			name:  "space replaced with underscore",
+			input: "node 1",
+			want:  "node_1",
+		},
+		{
+			name:  "colon replaced with underscore",
+			input: "node:1",
+			want:  "node_1",
+		},
+		{
+			name:  "at sign replaced with underscore",
+			input: "user@node",
+			want:  "user_node",
+		},
+		{
+			name:  "forward slash replaced",
+			input: "path/to/node",
+			want:  "path_to_node",
+		},
+		{
+			name:  "multiple special chars",
+			input: "node!@#$%^&*()+=[]{}|\\:;<>,?/~`",
+			want:  "node___________________________",
+		},
+		{
+			name:  "unicode replaced with underscore",
+			input: "节点1",
+			want:  "__1",
+		},
+		{
+			name:  "emoji replaced",
+			input: "server🔥hot",
+			want:  "server_hot",
+		},
+
+		// Length limits
+		{
+			name:  "exactly 63 chars preserved",
+			input: "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0",
+			want:  "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0",
+		},
+		{
+			name:  "longer than 63 chars truncated",
+			input: "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0123456789",
+			want:  "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0",
+		},
+		{
+			name:  "very long hostname truncated",
+			input: "this-is-a-very-long-hostname-that-exceeds-the-prometheus-label-value-limit-of-sixty-three-characters",
+			want:  "this-is-a-very-long-hostname-that-exceeds-the-prometheus-label-",
+		},
+
+		// Edge cases
+		{
+			name:  "empty string returns unknown",
+			input: "",
+			want:  "unknown",
+		},
+		{
+			name:  "all special chars returns unknown",
+			input: "!@#$%",
+			want:  "_____",
+		},
+		{
+			name:  "single char",
+			input: "a",
+			want:  "a",
+		},
+		{
+			name:  "numbers only",
+			input: "12345",
+			want:  "12345",
+		},
+		{
+			name:  "hyphen start preserved",
+			input: "-node",
+			want:  "-node",
+		},
+		{
+			name:  "underscore start preserved",
+			input: "_node",
+			want:  "_node",
+		},
+		{
+			name:  "dot start preserved",
+			input: ".hidden",
+			want:  ".hidden",
+		},
+
+		// Realistic node names
+		{
+			name:  "proxmox node style",
+			input: "pve-node1",
+			want:  "pve-node1",
+		},
+		{
+			name:  "ip address style",
+			input: "192.168.1.100",
+			want:  "192.168.1.100",
+		},
+		{
+			name:  "kubernetes node",
+			input: "k8s-worker-01.cluster.local",
+			want:  "k8s-worker-01.cluster.local",
+		},
+		{
+			name:  "docker container id prefix",
+			input: "abc123def456",
+			want:  "abc123def456",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := sanitizeNodeLabel(tt.input)
+			if got != tt.want {
+				t.Errorf("sanitizeNodeLabel(%q) = %q, want %q", tt.input, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestSanitizeNodeLabel_MaxLength(t *testing.T) {
+	// Test that all outputs are <= 63 chars
+	longInputs := []string{
+		"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+		"very-long-hostname-with-many-hyphens-and-lots-of-segments-here",
+		"node123456789012345678901234567890123456789012345678901234567890",
+	}
+
+	for _, input := range longInputs {
+		result := sanitizeNodeLabel(input)
+		if len(result) > 63 {
+			t.Errorf("sanitizeNodeLabel(%q) length = %d, want <= 63", input, len(result))
+		}
+	}
+}
+
+func TestSanitizeNodeLabel_NeverEmpty(t *testing.T) {
+	// Test that output is never empty
+	emptyishInputs := []string{
+		"",
+		"   ",
+	}
+
+	for _, input := range emptyishInputs {
+		result := sanitizeNodeLabel(input)
+		if result == "" {
+			t.Errorf("sanitizeNodeLabel(%q) returned empty string, should return 'unknown' or sanitized value", input)
+		}
+	}
+}
+
+func TestSanitizeNodeLabel_Idempotent(t *testing.T) {
+	// Applying sanitize twice should give same result as once
+	inputs := []string{
+		"node1",
+		"Node@Server",
+		"test.node.local",
+		"mixed-CASE_name.123",
+	}
+
+	for _, input := range inputs {
+		once := sanitizeNodeLabel(input)
+		twice := sanitizeNodeLabel(once)
+		if once != twice {
+			t.Errorf("sanitizeNodeLabel is not idempotent: sanitizeNodeLabel(%q) = %q, sanitizeNodeLabel(%q) = %q",
+				input, once, once, twice)
+		}
+	}
+}