tolerate empty matches for response vars

Author: theodore-s-beers

checks/http.go

@@ -215,7 +215,7 @@ func parseVariables(body []byte, vardefs []api.HTTPRequestResponseVariable, vari
 				return fmt.Errorf("invalid response body variable configuration")
 			}
 			matches := re.FindStringSubmatch(bodyString)
-			if len(matches) == 2 && matches[1] != "" {
+			if len(matches) == 2 {
 				variables[vardef.Name] = matches[1]
 			}
 
@@ -254,7 +254,7 @@ func parseHeaderVariables(headers map[string]string, vardefs []api.HTTPRequestRe
 			}
 
 			matches := re.FindStringSubmatch(headerValue)
-			if len(matches) != 2 || matches[1] == "" {
+			if len(matches) != 2 {
 				continue
 			}
 			value = matches[1]

checks/http_test.go

@@ -205,9 +205,10 @@ func TestParseVariablesLeavesMissingValuesUnset(t *testing.T) {
 func TestParseVariablesCapturesBodyRegex(t *testing.T) {
 	variables := map[string]string{}
 	err := parseVariables(
-		[]byte(`<a href="/password-reset/abc123">reset</a>`),
+		[]byte(`<a href="/password-reset/abc123?next=">reset</a>`),
 		[]api.HTTPRequestResponseVariable{
 			{Name: "resetToken", BodyRegex: `/password-reset/([a-z0-9]+)`},
+			{Name: "nextPath", BodyRegex: `next=([^"]*)`},
 		},
 		variables,
 	)
@@ -217,6 +218,9 @@ func TestParseVariablesCapturesBodyRegex(t *testing.T) {
 	if variables["resetToken"] != "abc123" {
 		t.Fatalf("resetToken = %q, want abc123", variables["resetToken"])
 	}
+	if nextPath, ok := variables["nextPath"]; !ok || nextPath != "" {
+		t.Fatalf("nextPath = %q, %t, want empty string, true", nextPath, ok)
+	}
 }
 
 func TestParseVariablesRequiresCaptureSource(t *testing.T) {
@@ -237,9 +241,13 @@ func TestParseVariablesRequiresCaptureSource(t *testing.T) {
 func TestParseHeaderVariablesLeavesMissingValuesUnset(t *testing.T) {
 	variables := map[string]string{}
 	err := parseHeaderVariables(
-		map[string]string{"Set-Cookie": "session_id=abc123; Path=/; HttpOnly"},
+		map[string]string{
+			"Set-Cookie": "session_id=abc123; Path=/; HttpOnly",
+			"Location":   "/login?next=",
+		},
 		[]api.HTTPRequestResponseHeaderVariable{
 			{Name: "sessionID", Header: "Set-Cookie", Regex: "session_id=([^;]+)"},
+			{Name: "nextPath", Header: "Location", Regex: "next=([^&]*)"},
 			{Name: "missingHeader", Header: "X-Missing"},
 			{Name: "missingMatch", Header: "Set-Cookie", Regex: "missing=([^;]+)"},
 		},
@@ -251,6 +259,9 @@ func TestParseHeaderVariablesLeavesMissingValuesUnset(t *testing.T) {
 	if variables["sessionID"] != "abc123" {
 		t.Fatalf("sessionID = %q, want abc123", variables["sessionID"])
 	}
+	if nextPath, ok := variables["nextPath"]; !ok || nextPath != "" {
+		t.Fatalf("nextPath = %q, %t, want empty string, true", nextPath, ok)
+	}
 	if _, ok := variables["missingHeader"]; ok {
 		t.Fatalf("expected missing header variable to remain unset")
 	}