Adding some basic tests

ssl_exporter_test.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+func TestProbeHandler(t *testing.T) {
+
+	// Test the behaviour of various target URIs
+	//    'ok' denotes whether we expect a succesful https connection
+	//    'insecure' denotes whether we ignore invalid certs
+	cases := []struct {
+		uri      string
+		ok       bool
+		insecure bool
+	}{
+		// Test against an assumed valid, reachable and functioning HTTPS address
+		{uri: "https://google.com", ok: true, insecure: false},
+		// Test against a HTTP address
+		{uri: "http://google.com", ok: false, insecure: false},
+		// Test against an expired certificate when we're rejecting invalid certs
+		{uri: "https://expired.badssl.com", ok: false, insecure: false},
+		// Test against an expired certificate when we're accepting invalid certs
+		{uri: "https://expired.badssl.com", ok: true, insecure: true},
+		// Test against a target with no protocol
+		{uri: "google.com", ok: false, insecure: false},
+		// Test against a string with spaces
+		{uri: "with spaces", ok: false, insecure: false},
+		// Test against nothing
+		{uri: "", ok: false, insecure: false},
+	}
+
+	fmt.Println("Note: The error logs in these tests are expected. One of the important tests is that we return the expected body, even in the face of errors.")
+
+	for _, test := range cases {
+
+		uri := "/probe?target=" + test.uri
+		req, err := http.NewRequest("GET", uri, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		rr := httptest.NewRecorder()
+		handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			probeHandler(w, r, test.insecure)
+		})
+
+		handler.ServeHTTP(rr, req)
+
+		// We should always return a 200, no matter what
+		if status := rr.Code; status != http.StatusOK {
+			t.Errorf("handler returned wrong status code: got %v want %v",
+				status, http.StatusOK)
+		}
+
+		// Make sure we're getting the ssl_https_connect_success metric back
+		successString, err := regexp.MatchString("(ssl_https_connect_success [0-1])", rr.Body.String())
+		if err != nil {
+			t.Errorf("regexp against response body returned an error w/ %q", uri)
+		}
+		if !successString {
+			t.Errorf("can't find ssl_https_connect_success metric in response body w/ %q", uri)
+		}
+
+		// Make sure we're getting the result we expect from ssl_https_connect_success
+		ok := strings.Contains(rr.Body.String(), "ssl_https_connect_success 1")
+		if test.ok && !ok {
+			t.Errorf("expected https connection to succeed but it failed w/ %q", uri)
+		}
+		if !test.ok && ok {
+			t.Errorf("expected https connection to fail but it succeeded w/ %q", uri)
+		}
+
+	}
+}