Issue 2664 - Remove ignoreHeaders argument from parseFilter(s) and move the logic to the UI

lib/filterValidation.js

Index: lib/filterValidation.js
===================================================================
--- a/lib/filterValidation.js
+++ b/lib/filterValidation.js
@@ -19,6 +19,63 @@
 
 let {Filter, InvalidFilter, ElemHideBase} = require("filterClasses");
 
+/**
+ * An error returned by
+ * {@link module:filterValidation.parseFilter parseFilter()} or
+ * {@link module:filterValidation.parseFilters parseFilters()}
+ * indicating that a given filter cannot be parsed,
+ * contains an invalid CSS selector or is a filter list header.
+ *
+ * @constructor
+ */
+function FilterParsingError(type, details)
+{
+  /**
+   * Indicates why the filter is rejected. Possible choices:
+   * "invalid-filter", "invalid-css-selector", "unexpected-filter-list-header"
+   *
+   * @type {string}
+   */
+  this.type = type;
+
+  if (details)
+  {
+    if ("reason" in details)
+      this.reason = details.reason;
+    if ("selector" in details)
+      this.selector = details.selector;
+  }
+}
+FilterParsingError.prototype = {
+  /**
+   * The line number the error occurred on if
+   * {@link module:filterValidation.parseFilters parseFilters()}
+   * were used. Or null if the error was returned by
+   * {@link module:filterValidation.parseFilter parseFilter()}.
+   *
+   * @type {?number}
+   */
+  lineno: null,
+
+  /**
+   * Returns a detailed translated error message.
+   *
+   * @return {string}
+   */
+  toString: function()
+  {
+    let message = this.reason || ext.i18n.getMessage(
+      this.type.replace(/-/g, "_"),
+      "selector" in this ? "'" + this.selector + "'" : null
+    );
+
+    if (this.lineno)
+      message = ext.i18n.getMessage("line", this.lineno.toLocaleString()) + ": " + message;
+
+    return message;
+  }
+};
+
 function isValidCSSSelector(selector)
 {
   let style = document.createElement("style");
@@ -40,10 +97,10 @@
 
 /**
  * @typedef ParsedFilter
- * @property {?Filter} [filter]  The parsed filter if it is valid. Or null if
- *                               the given string is empty or a filter list header.
- * @property {string} [error]    An error message indicated that the filter cannot
- *                               be parsed or contains an invalid CSS selector.
+ * @property {?Filter} [filter]  The parsed filter if it is valid.
+ *                               Or null if the given string is empty.
+ * @property {FilterParsingError} [error]  See {@link module:filterValidation~FilterParsingError FilterParsingError}
+ *
  */
 
 let parseFilter =
@@ -51,32 +108,25 @@
  * Parses and validates a filter given by the user.
  *
  * @param {string}  text
- * @param {Boolean} [ignoreHeaders=false]  If true, {filter: null} is
-                                           returned instead an error
-                                           for filter list headers.
  * @return {ParsedFilter}
  */
-exports.parseFilter = function(text, ignoreHeaders)
+exports.parseFilter = function(text)
 {
   let filter = null;
   text = Filter.normalize(text);
 
   if (text)
   {
-    if (text[0] != "[")
-    {
-      filter = Filter.fromText(text);
+    if (text[0] == "[")
+      return {error: new FilterParsingError("unexpected-filter-list-header")};
 
-      if (filter instanceof InvalidFilter)
-        return {error: filter.reason};
+    filter = Filter.fromText(text);
 
-      if (filter instanceof ElemHideBase && !isValidCSSSelector(filter.selector))
-        return {error: ext.i18n.getMessage("invalid_css_selector", "'" + filter.selector + "'")};
-    }
-    else if (!ignoreHeaders)
-    {
-      return {error: ext.i18n.getMessage("unexpected_filter_list_header")};
-    }
+    if (filter instanceof InvalidFilter)
+      return {error: new FilterParsingError("invalid-filter", {reason: filter.reason})};
+
+    if (filter instanceof ElemHideBase && !isValidCSSSelector(filter.selector))
+      return {error: new FilterParsingError("invalid-css-selector", {selector: filter.selector})};
   }
 
   return {filter: filter};
@@ -84,35 +134,35 @@
 
 /**
  * @typedef ParsedFilters
- * @property {Filter[]} [filters]  The parsed filters if all of them are valid.
- * @property {string} [error]      An error message indicated that any filter cannot
- *                                 be parsed or contains an invalid CSS selector.
+ * @property {Filter[]} filters  The parsed result without invalid filters.
+ * @property {FilterParsingError[]} errors  See {@link module:filterValidation~FilterParsingError FilterParsingError}
  */
 
 /**
  * Parses and validates a newline-separated list of filters given by the user.
  *
  * @param {string}  text
- * @param {Boolean} [ignoreHeaders=false]  If true, filter list headers
- *                                         will be stripped instead of
- *                                         returning an error.
  * @return {ParsedFilters}
  */
-exports.parseFilters = function(text, ignoreHeaders)
+exports.parseFilters = function(text)
 {
   let lines = text.split("\n");
   let filters = [];
+  let errors = [];
 
   for (let i = 0; i < lines.length; i++)
   {
-    let {filter, error} = parseFilter(lines[i], ignoreHeaders);
-
-    if (error)
-      return {error: ext.i18n.getMessage("line", (i + 1).toString()) + ": " + error};
+    let {filter, error} = parseFilter(lines[i]);
 
     if (filter)
       filters.push(filter);
+
+    if (error)
+    {
+      error.lineno = i + 1;
+      errors.push(error);
+    }
   }
 
-  return {filters: filters};
+  return {filters: filters, errors: errors};
 };