add small tests for the prometheus-exporter functions

tools/prometheus-exporter_test.go

@@ -0,0 +1,173 @@
+package tools
+
+import (
+	"testing"
+
+	"github.com/test-go/testify/assert"
+	"github.com/test-go/testify/require"
+)
+
+func intPtr(i int) *int {
+	return &i
+}
+
+func TestParseEndpoint(t *testing.T) {
+	tests := []struct {
+		name     string
+		endpoint string
+		want     struct {
+			host       string
+			startBlock *int
+			params     map[string]string
+			err        error
+		}
+	}{
+		{
+			name:     "valid endpoint with params",
+			endpoint: "my.domain:443?namespace=eth-mainnet",
+			want: struct {
+				host       string
+				startBlock *int
+				params     map[string]string
+				err        error
+			}{
+				host: "my.domain:443",
+				params: map[string]string{
+					"namespace": "eth-mainnet",
+				},
+				startBlock: nil,
+				err:        nil,
+			},
+		},
+		{
+			name:     "another example with both",
+			endpoint: "arb-one.streamingfast.io:443@123?namespace=arb-one",
+			want: struct {
+				host       string
+				startBlock *int
+				params     map[string]string
+				err        error
+			}{
+				host: "arb-one.streamingfast.io:443",
+				params: map[string]string{
+					"namespace": "arb-one",
+				},
+				startBlock: intPtr(123),
+				err:        nil,
+			},
+		},
+		{
+			name:     "valid endpoint with params and start block",
+			endpoint: "my.domain:443@-10?namespace=eth-mainnet&region=us-east",
+			want: struct {
+				host       string
+				startBlock *int
+				params     map[string]string
+				err        error
+			}{
+				host: "my.domain:443",
+				params: map[string]string{
+					"namespace": "eth-mainnet",
+					"region":    "us-east",
+				},
+				startBlock: intPtr(-10),
+				err:        nil,
+			},
+		},
+		{
+			name:     "valid endpoint with reversed params and start block",
+			endpoint: "my.domain:443?namespace=eth-mainnet&region=us-east@1234",
+			want: struct {
+				host       string
+				startBlock *int
+				params     map[string]string
+				err        error
+			}{
+				host: "my.domain:443",
+				params: map[string]string{
+					"namespace": "eth-mainnet",
+					"region":    "us-east",
+				},
+				startBlock: intPtr(1234),
+				err:        nil,
+			},
+		},
+		{
+			name:     "valid endpoint no params",
+			endpoint: "my.domain:443",
+			want: struct {
+				host       string
+				startBlock *int
+				params     map[string]string
+				err        error
+			}{
+				host:       "my.domain:443",
+				startBlock: nil,
+				params:     nil,
+				err:        nil,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			host, startBlock, params, err := parseEndpoint(tt.endpoint)
+			require.Equal(t, tt.want.err, err)
+			assert.EqualValues(t, tt.want.startBlock, startBlock)
+			assert.Equal(t, tt.want.host, host)
+			require.Equal(t, tt.want.params, params)
+		})
+	}
+}
+
+func TestExtractParams(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want map[string]string
+	}{
+		{
+			name: "single param",
+			in:   "namespace=eth-mainnet",
+			want: map[string]string{
+				"namespace": "eth-mainnet",
+			},
+		},
+		{
+			name: "multiple params",
+			in:   "namespace=eth-mainnet&region=us-east-1",
+			want: map[string]string{
+				"namespace": "eth-mainnet",
+				"region":    "us-east-1",
+			},
+		},
+		{
+			name: "no params",
+			in:   "",
+			want: map[string]string{},
+		},
+		{
+			name: "empty param value",
+			in:   "key=&blah=bloh",
+			want: map[string]string{
+				"key":  "",
+				"blah": "bloh",
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := extractParams(tt.in)
+			require.NoError(t, err)
+			if len(got) != len(tt.want) {
+				t.Errorf("extractParams() got %v params, want %v", len(got), len(tt.want))
+			}
+			for k, v := range tt.want {
+				if got[k] != v {
+					t.Errorf("extractParams()[%q] = %v, want %v", k, got[k], v)
+				}
+			}
+		})
+	}
+}