fix log condition

src/scriptlets/trusted-replace-fetch-response.js

@@ -33,9 +33,10 @@ import {
  * - pattern - optional, argument for matching contents of responseText that should be replaced. If set, `replacement` is required;
  * possible values:
  *   - '*' to match all text content
- *   - string
+ *   - non-empty string
  *   - regular expression
- * - replacement — optional, should be set if `pattern` is set. String to replace the response text content matched by `pattern`. Empty string to remove content.
+ * - replacement — optional, should be set if `pattern` is set. String to replace the response text content matched by `pattern`.
+ * Empty string to remove content. Defaults to empty string.
  * - propsToMatch - optional, string of space-separated properties to match; possible props:
  *   - string or regular expression for matching the URL passed to fetch call; empty string, wildcard `*` or invalid regular expression will match all fetch calls
  *   - colon-separated pairs `name:value` where
@@ -74,7 +75,7 @@ import {
  *     ```
  */
 /* eslint-enable max-len */
-export function trustedReplaceFetchResponse(source, pattern = '', replacement = '', propsToMatch) {
+export function trustedReplaceFetchResponse(source, pattern = '', replacement = '', propsToMatch = '') {
     // do nothing if browser does not support fetch or Proxy (e.g. Internet Explorer)
     // https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch
     // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy
@@ -84,14 +85,17 @@ export function trustedReplaceFetchResponse(source, pattern = '', replacement =
         return;
     }
 
-    const shouldLog = typeof pattern === 'undefined';
+    // eslint-disable-next-line no-console
+    const log = console.log.bind(console);
 
-    if (!shouldLog && (pattern === '' || typeof replacement === 'undefined')) {
+    // Only allow pattern as empty string for logging purposes
+    if (pattern === '' && replacement !== '') {
+        const logMessage = 'log: Pattern argument should not be empty string.';
+        log(source, logMessage);
         return;
     }
+    const shouldLog = pattern === '' && replacement === '';
 
-    // eslint-disable-next-line no-console
-    const log = console.log.bind(console);
     const nativeFetch = fetch;
 
     let shouldReplace = false;

src/scriptlets/trusted-replace-xhr-response.js

@@ -31,7 +31,7 @@ import {
  * - pattern - optional, argument for matching contents of responseText that should be replaced. If set, `replacement` is required;
  * possible values:
  *   - '*' to match all text content
- *   - string
+ *   - non-empty string
  *   - regular expression
  * - replacement — optional, should be set if `pattern` is set. String to replace matched content with. Empty string to remove content.
  * - propsToMatch — optional, string of space-separated properties to match for extra condition; possible props:
@@ -77,12 +77,18 @@ export function trustedReplaceXhrResponse(source, pattern = '', replacement = ''
         return;
     }
 
-    if (typeof pattern === 'undefined' || typeof replacement === 'undefined') {
+    // eslint-disable-next-line no-console
+    const log = console.log.bind(console);
+
+    // Only allow pattern as empty string for logging purposes
+    if (pattern === '' && replacement !== '') {
+        const logMessage = 'log: Pattern argument should not be empty string.';
+        log(source, logMessage);
         return;
     }
 
-    // eslint-disable-next-line no-console
-    const log = console.log.bind(console);
+    const shouldLog = pattern === '' && replacement === '';
+
     const nativeOpen = window.XMLHttpRequest.prototype.open;
     const nativeSend = window.XMLHttpRequest.prototype.send;
 
@@ -93,7 +99,7 @@ export function trustedReplaceXhrResponse(source, pattern = '', replacement = ''
     const openWrapper = (target, thisArg, args) => {
         xhrData = getXhrData(...args);
 
-        if (pattern === '' && replacement === '') {
+        if (shouldLog) {
             // Log if no propsToMatch given
             const logMessage = `log: xhr( ${objectToString(xhrData)} )`;
             log(source, logMessage);